The Renewable Heat Incentive Consultation closes today. Thanks to Kate de Selincourt who alerted me to this. I spent 40 minutes replying to some of the many questions and thought I would share my responses with blog readers. If you want to put your five pence worth in, be quick. It's here: RHI Consultation
1. What are your views about the proposed approach of a universally available tariff scheme? Is a tariff scheme the most efficient way to drive down technology costs, increase innovation and value for money, together with developing a homegrown supply chain? Please include reasoning for your response.
No, I think a tariff scheme, especially a deemed tariff scheme is not the way to go here. It seems to be modelled on FITs which have themselves been copied from Germany. FITs have been successful because they have been generous, but an installation-based subsidy has the potential to be just as successful and would be easier to comprehend from the consumer's standpoint and to administer for government agencies.
2. Do you think that there would be advantages in phasing or piloting roll out of the scheme? On what basis do you think it might make sense to phase or pilot the scheme?
Not really. FITS have been around long enough for us to know what is likely to happen. RHI has already been delayed. "Phasing" sounds like a polite way of adding further delay.
3. Do you think that there may be alternative or additional approaches to incentivising renewable heat deployment that we should pursue? What approaches do you think might add most value?
Yes. If there is to be any subsidy, it should be towards the installation costs. As with almost all non-fossil fuelled power sources, the running costs are generally much lower. It's the capital costs which are the barrier to uptake. Consequently, it makes little sense to incentivise the running costs, which is what the RHI is planning to do. The entry barriers remain just as large as ever, and only the rich or well connected will be able to take advantage of the RHI. This makes it regressive.
10. Do you agree with the proposed eligible technologies set out above? Are there others that should be considered for inclusion?
No, I don't. I am critical of the inclusion of biomass for reasons already made known to DECC. It is quite wrong-headed of us to be subsidising the burning of carbon-intensive fuels, and biomass is carbon-intensive. The inclusion of biomass in the RHI seems to be all about meeting 2020 EU targets for renewable usage, but that doesn't stop it being bad science.
If we must subsidise here, let's encourage the use of timber and other biomass materials in construction, where the carbon will be locked up for the critical years ahead when we have to reduce CO2 emissions.
11. Do you agree that an approved suppliers scheme is the best option for domestic biomass heat installations to demonstrate their use of sustainable fuel? Please provide reasoning with your response.
Hard to answer as I don't agree that biomass is a sustainable fuel. I guess some sort of auditing on the supply side is preferable to none at all, but I fear if biomass really takes off as a fuel source, that it will be sourced from further and further afield and that the auditing is likely to be compromised.
12. Do you agree that as part of the approved biomass supplier list we should assume a level of boiler efficiency?
Yes, if biomass is to be burnt, then at least control the boiler efficiencies. Insist on condensing biomass boilers at the very least.
23. What is the risk of switchback after the period over which tariff payments are made? Do you think this applies solely to biomass?
If you provide a mechanism for people to harvest a subsidy for their fuel bills, then of course there is a risk they will find another way of providing heating after the subsidy is withdrawn. That is yet another reason why capital cost subsidy is preferable.
39. Do you agree that deeming, as opposed to metering, is the most appropriate approach on which to base the calculation of RHI payments? If not, why not?
I can see why deeming is the preferred method, but I don't like it. It seems to highlight yet another problem with subsidising running costs, and not installation costs.
Showing posts with label Heat Pumps. Show all posts
Showing posts with label Heat Pumps. Show all posts
3 Apr 2012
The Future of Heating?
DECC (the Department of Energy and Climate Change) have published a document called The Future of Heating. It's what you might call a partial roadmap (yes, another one) describing how we might heat our homes and fire up what's left of our industry by 2050. I've spent a day immersed in it and have come away with some strange feelings.
It strikes me as a very strange document. It wings its way through 106 pages (typical for the genre) and goes into a fair amount of detail about many of the options facing us. Every now and then it asks for feedback, preferably evidence or experience-based. Nothing wrong with that, except that its never entirely clear whether its a narrative, a policy document or a consultation exercise. And its not entirely clear what sort of feedback they are looking for. Some of it very general, other questions are very specific.
I'm afraid I can't be much help on either front. For instance, I don't have experience of heat networks and I can't demonstrate the costs and benefits of them in reducing emissions, fuel poverty and/or fuel consumption. Neither can I tell you whether its a good idea to regulate the supply of heat through the networks. I feel so useless.
But another part of me feels that this document is actually designed to make me feel useless, because it seems to have everything under control. They don't need to know what little I know about heat networks because some geek at DECC has already been out there and done some research, and if you piece all this research together into one document, bugger me if you don't have a fully fledged strategy for a low carbon 2050. Yippee.
Only I didn't go Yippee at all. Instead I was left wondering about all the very basic questions they haven't asked. Like how much low carbon energy we will have to play with in 2050? And what will it cost? Without this information, every other policy set out in this document is nothing but conjecture.
Take §27 in the Exec Summary. It starts Reducing our demand for heat is a highly cost effective way of cutting emissions from buildings. Well, is it? No evidence is given to support this statement, it is just assumed to be the case. It might be cost effective to reduce demand by a little bit, but very expensive to reduce it by a lot (more than likely in fact). And without having some idea of what low carbon power sources will be available and how much they will cost, the cost-effectiveness of demand reduction is nothing more than guesswork.
I could go on, but it would labour the point. To be fair, the purpose of the document is to look at the many ways there are of being efficient with heat, from undertaking extreme retrofits to building heat networks and creating inter-seasonal heat stores. Even low carbon cooking gets a look-in. It's nothing if not a thorough review of all the options that are potentially there.
But it's all just a bit weightless. Without some way of knowing what energy will cost, we have no way of making any judgements about what will be worth doing, and what we can safely discard. The document ends up being nothing more than a long list of possible solutions, mixed in with boundless good intentions. We are informed that the grid will be decarbonised, but aren't told how much electricity it will supply. Nor are we informed whether we can use this electricity directly for heating, though we are given a hefty nod in that direction by the many hints dropped that heat pumps are about to save us all.
Instead, we are informed that the Green Deal, the Energy Company Obligation and Smart Meters will remove upfront costs, help vulnerable consumers and enable people to make the best use of their energy. Maybe, but at this point it starts to read like an election manifesto, and I begin to loose the will to carry on reading.....
It strikes me as a very strange document. It wings its way through 106 pages (typical for the genre) and goes into a fair amount of detail about many of the options facing us. Every now and then it asks for feedback, preferably evidence or experience-based. Nothing wrong with that, except that its never entirely clear whether its a narrative, a policy document or a consultation exercise. And its not entirely clear what sort of feedback they are looking for. Some of it very general, other questions are very specific.
I'm afraid I can't be much help on either front. For instance, I don't have experience of heat networks and I can't demonstrate the costs and benefits of them in reducing emissions, fuel poverty and/or fuel consumption. Neither can I tell you whether its a good idea to regulate the supply of heat through the networks. I feel so useless.
But another part of me feels that this document is actually designed to make me feel useless, because it seems to have everything under control. They don't need to know what little I know about heat networks because some geek at DECC has already been out there and done some research, and if you piece all this research together into one document, bugger me if you don't have a fully fledged strategy for a low carbon 2050. Yippee.
Only I didn't go Yippee at all. Instead I was left wondering about all the very basic questions they haven't asked. Like how much low carbon energy we will have to play with in 2050? And what will it cost? Without this information, every other policy set out in this document is nothing but conjecture.
Take §27 in the Exec Summary. It starts Reducing our demand for heat is a highly cost effective way of cutting emissions from buildings. Well, is it? No evidence is given to support this statement, it is just assumed to be the case. It might be cost effective to reduce demand by a little bit, but very expensive to reduce it by a lot (more than likely in fact). And without having some idea of what low carbon power sources will be available and how much they will cost, the cost-effectiveness of demand reduction is nothing more than guesswork.
I could go on, but it would labour the point. To be fair, the purpose of the document is to look at the many ways there are of being efficient with heat, from undertaking extreme retrofits to building heat networks and creating inter-seasonal heat stores. Even low carbon cooking gets a look-in. It's nothing if not a thorough review of all the options that are potentially there.
But it's all just a bit weightless. Without some way of knowing what energy will cost, we have no way of making any judgements about what will be worth doing, and what we can safely discard. The document ends up being nothing more than a long list of possible solutions, mixed in with boundless good intentions. We are informed that the grid will be decarbonised, but aren't told how much electricity it will supply. Nor are we informed whether we can use this electricity directly for heating, though we are given a hefty nod in that direction by the many hints dropped that heat pumps are about to save us all.
Instead, we are informed that the Green Deal, the Energy Company Obligation and Smart Meters will remove upfront costs, help vulnerable consumers and enable people to make the best use of their energy. Maybe, but at this point it starts to read like an election manifesto, and I begin to loose the will to carry on reading.....
2 Aug 2011
Cantor on Air Source Heat Pumps
John Cantor has a deserved reputation as a knowledgeable and independent commentator on all things heat pump. And here he has distilled much of what he knows on the vexed issue of air-source heat pumps. Anyone thinking of installing such a beast would do well to read through John's thoughts beforehand.
He looks at why so many people end up being disappointed by their heat pumps, and what they might have done to ensure that the installation had worked better for them. He analyses the Energy Savings Trust survey last year which showed generally poor results for ASHPs, and undertakes some comparisons with Germany and Switzerland where heat pumps are more widely used and apparently give better results. And he looks at the implications of the widespread adoption of heat pumps to UK energy policy - can the Grid cope?
All in all, a really useful contribution to the debate, and a very practical guide as well.
He looks at why so many people end up being disappointed by their heat pumps, and what they might have done to ensure that the installation had worked better for them. He analyses the Energy Savings Trust survey last year which showed generally poor results for ASHPs, and undertakes some comparisons with Germany and Switzerland where heat pumps are more widely used and apparently give better results. And he looks at the implications of the widespread adoption of heat pumps to UK energy policy - can the Grid cope?
All in all, a really useful contribution to the debate, and a very practical guide as well.
28 Feb 2011
The Mackay Calculator gets even bigger
I've probably made a complete fool of myself, but vanity got the better of me last week and I agreed to test drive Prof. David Mackay's 2050 Pathway calculator. That's the spreadsheet (dressed up as a series of checkboxes and natty graphs) which he has created to try and tease out just how we might go about making the UK a low carbon sort of place by 2050 (just in time for my 97th birthday).
The results of my haphazard navigation are about to go on public display at the DECC website and, worse still, I am meant to be taking part in an online debate with some other guinea pigs on Thursday and Friday this week. It's being hailed as an energy-literate conversation, but trying to get to grips with this project is enough to make anyone feel like a numpty. You can't help but come into an exercise like this without carrying baggage, and I anticipated it being a showdown between pro- and anti-nuclear camps, but the funny thing is that, if you tweak the calculations a little, you can very easily arrive at a situation where we are literally swamped with low carbon electricity and are desperately exporting it to all and sundry. You can do this with or without nuclear power, so this particular aspect of the debate rather palls into insignificance.
Much more worrying, for me, is the decision on what to replace oil and gas with. At the moment, Mackay reckons it's biofuels or heat pumps, but of course I don't really warm towards either. That's my baggage. And also, I suspect, the reason I have been asked to guinea pig this stage of the project. "That Brinkley," thinks the Prof, "he hasn't a good word to say about biofuels or heat pumps, and he's always criticising the Renewable Heat Incentive, so let him try and work out how to get to 80% carbon reduction without them, ha!" Indeed, I'm not sure I can, so my immediate instinct is to call foul and to complain that there aren't enough checkboxes for the hydrogen economy which I imagine may ride to the rescue with a train load of fuel cells. Well, 2050 is still a long way off: it's pretty much all speculation, isn't it?
You can of course tweak the demand side as well, which I did with abandon. This makes everything about fifteen times more complicated, but it still leaves a big gap around heating, even if you max out every lever you have.
There's certainly some food for thought here. Take a look after Thursday and see what you make of it. It's going to be somewhere around here.
Mackay gets a nod as well today on a fascinating article about thermal underwear on the Low Tech site. No, really, it is fascinating. What interests them here is the Professor's claim that the average temperature in UK homes was 13°C in 1970. They ask how he knows this. In fact, this claim is expanded upon in the 2050 Pathway explanatory text which suggests the following:
The mean internal temperature of UK homes during the winter months was 17.5°C in 2007, compared with 16°C in 1990.
In fact, Mackay shows a graph of average internal temperature from 1970 to 2050. All good stuff, but just where does this information come from? And can we believe it?
In the meantime, it's off to Ecobuild where I'll be on Tuesday and Wednesday. In fact, I am on the rota to populate the PassivHaus trust stand on Wednesday afternoon, 2-4, so do drop by if you want to upbraid me.
The results of my haphazard navigation are about to go on public display at the DECC website and, worse still, I am meant to be taking part in an online debate with some other guinea pigs on Thursday and Friday this week. It's being hailed as an energy-literate conversation, but trying to get to grips with this project is enough to make anyone feel like a numpty. You can't help but come into an exercise like this without carrying baggage, and I anticipated it being a showdown between pro- and anti-nuclear camps, but the funny thing is that, if you tweak the calculations a little, you can very easily arrive at a situation where we are literally swamped with low carbon electricity and are desperately exporting it to all and sundry. You can do this with or without nuclear power, so this particular aspect of the debate rather palls into insignificance.
Much more worrying, for me, is the decision on what to replace oil and gas with. At the moment, Mackay reckons it's biofuels or heat pumps, but of course I don't really warm towards either. That's my baggage. And also, I suspect, the reason I have been asked to guinea pig this stage of the project. "That Brinkley," thinks the Prof, "he hasn't a good word to say about biofuels or heat pumps, and he's always criticising the Renewable Heat Incentive, so let him try and work out how to get to 80% carbon reduction without them, ha!" Indeed, I'm not sure I can, so my immediate instinct is to call foul and to complain that there aren't enough checkboxes for the hydrogen economy which I imagine may ride to the rescue with a train load of fuel cells. Well, 2050 is still a long way off: it's pretty much all speculation, isn't it?
You can of course tweak the demand side as well, which I did with abandon. This makes everything about fifteen times more complicated, but it still leaves a big gap around heating, even if you max out every lever you have.
There's certainly some food for thought here. Take a look after Thursday and see what you make of it. It's going to be somewhere around here.
Mackay gets a nod as well today on a fascinating article about thermal underwear on the Low Tech site. No, really, it is fascinating. What interests them here is the Professor's claim that the average temperature in UK homes was 13°C in 1970. They ask how he knows this. In fact, this claim is expanded upon in the 2050 Pathway explanatory text which suggests the following:
The mean internal temperature of UK homes during the winter months was 17.5°C in 2007, compared with 16°C in 1990.
In fact, Mackay shows a graph of average internal temperature from 1970 to 2050. All good stuff, but just where does this information come from? And can we believe it?
In the meantime, it's off to Ecobuild where I'll be on Tuesday and Wednesday. In fact, I am on the rota to populate the PassivHaus trust stand on Wednesday afternoon, 2-4, so do drop by if you want to upbraid me.
21 Oct 2010
Whither the Green Incentives?
So yesterday, George Osborne, the Chancellor, made his long awaited pronouncements on public spending. Of particular interest to this blog was the fate of the various green incentives, notably the Feed-in Tariff (FiT), the Renewable Heat Incentive (RHI) and the Green Deal. This is what he actually said:
The aim of all these investments is for Britain to be a leader of the new green economy. Creating jobs, saving energy costs, reducing carbon emissions. We will also introduce incentives to help families reduce their bills. We will introduce a funded Renewable Heat Incentive. Our Green Deal will encourage home energy efficiency at no upfront cost to homeowners and allow us to phase out the Warm Front programme.
The big news here is that the RHI survives. There has been feverish speculation that it was about to be ditched. There is more detail on the DECC website where we learn that:
£860 million funding for the Renewable Heat Incentive which will be introduced from 2011-12. This will drive a more-than-tenfold increase of renewable heat over the coming decade, shifting renewable heat from a fringe industry firmly into the mainstream. The Government will not be taking forward the previous administration’s plans of funding this scheme through an overly complex Renewable Heat levy.
It's all still rather delphic. Is the £860million a one-off? It sounds like a lot, but it's just 60,000 ground source heat pumps or biomass boilers, hardly enough to render them "mainstream." If commercial power plants get stuck in, the money will be gone in the blink of an eye. How will it be distributed? Who will qualify? What will the subsidies be worth? Until the details are published, we are not much the wiser. But it should at least be good news for all those heat pump suppliers whose order books have dried up this year because of the uncertainty over whether the RHI would survive in any fashion. Now they can say, "You will probably qualify for a subsidy but we can't say how much!" Great.
There is also more detail on FiTs
Feed-In Tariffs will be refocused on the most cost-effective technologies saving £40 million in 2014-15. The changes will be implemented at the first scheduled review of tariffs unless higher than expected deployment requires an early review.
It suggests that those who are currently signing up for the tariffs will be secure in the knowledge that the deal they are now getting will be good for many years. The statement that FiTs will be refocused on cost-effective technologies suggests, to me, that the very generous subsidies to solar PV will be greatly reduced, because it is by far the most expensive of the technologies covered.
As for the Green Deal? Nothing new here. We know it's coming, but what form it takes we have, as yet, no idea.
So the time for speculation is not past. I would be surprised if the RHI details will be available for many months yet. The FiT deal wasn't published until just before the FiT went live in April 2010, so I would expect those awaiting news of the critical levels of subsidy on the RHI to have wait a while longer yet. Not great news if you are still trying to decide how best to heat your home.
The aim of all these investments is for Britain to be a leader of the new green economy. Creating jobs, saving energy costs, reducing carbon emissions. We will also introduce incentives to help families reduce their bills. We will introduce a funded Renewable Heat Incentive. Our Green Deal will encourage home energy efficiency at no upfront cost to homeowners and allow us to phase out the Warm Front programme.
The big news here is that the RHI survives. There has been feverish speculation that it was about to be ditched. There is more detail on the DECC website where we learn that:
£860 million funding for the Renewable Heat Incentive which will be introduced from 2011-12. This will drive a more-than-tenfold increase of renewable heat over the coming decade, shifting renewable heat from a fringe industry firmly into the mainstream. The Government will not be taking forward the previous administration’s plans of funding this scheme through an overly complex Renewable Heat levy.
It's all still rather delphic. Is the £860million a one-off? It sounds like a lot, but it's just 60,000 ground source heat pumps or biomass boilers, hardly enough to render them "mainstream." If commercial power plants get stuck in, the money will be gone in the blink of an eye. How will it be distributed? Who will qualify? What will the subsidies be worth? Until the details are published, we are not much the wiser. But it should at least be good news for all those heat pump suppliers whose order books have dried up this year because of the uncertainty over whether the RHI would survive in any fashion. Now they can say, "You will probably qualify for a subsidy but we can't say how much!" Great.
There is also more detail on FiTs
Feed-In Tariffs will be refocused on the most cost-effective technologies saving £40 million in 2014-15. The changes will be implemented at the first scheduled review of tariffs unless higher than expected deployment requires an early review.
It suggests that those who are currently signing up for the tariffs will be secure in the knowledge that the deal they are now getting will be good for many years. The statement that FiTs will be refocused on cost-effective technologies suggests, to me, that the very generous subsidies to solar PV will be greatly reduced, because it is by far the most expensive of the technologies covered.
As for the Green Deal? Nothing new here. We know it's coming, but what form it takes we have, as yet, no idea.
So the time for speculation is not past. I would be surprised if the RHI details will be available for many months yet. The FiT deal wasn't published until just before the FiT went live in April 2010, so I would expect those awaiting news of the critical levels of subsidy on the RHI to have wait a while longer yet. Not great news if you are still trying to decide how best to heat your home.
28 Jul 2010
Renewable Heat Incentive: the chaos continues
I have already blogged extensively about the Renwable Heat Incentive (the RHI), and the problematic nature of this proposed subsidy for heat pumps, biomass boilers and hot water solar panels. It was launched back in February 2010 as a “consultation document” but, in truth, it was rather more than this because it gave details not only of the projected subsidies available but also of a timetable. It stated that it would come into effect in April 2011 and that anyone installing renewable heat equipment after July 2009 would qualify for the incentive. That sounds like a a detailed proposal to me. The document called for responses by April. That deadline has long since passed and there has been no word since then about what will happen next.
A change of government in May hasn’t helped, particularly as spending cuts now seem to be the order of the day. Potential customers are all delaying orders until the position of the RHI becomes clear. Manufacturers and installers are now having to lay off staff because the market has dried up because of the confusion. All that is needed is some guidance from central government to relieve the situation.
So yesterday, Chris Huhne, the Energy Secretary, gets up in parliament and delivers his first annual energy statement. Everyone connected to this small industry is holding their breath for news of the RHI. And this is what he says. “In the heating sector, I can confirm our strong commitment to action on renewable heat. The Government is considering responses to the Renewable Heat Incentive consultation and will set out detailed options following the Spending Review.”
Groans all round. That could mean anything. It certainly doesn’t sound like anything soonish. My guess is that we now won’t see any response to the RHI Consultation until sometime in 2011. By which time this small industry will be a whole lot smaller.
A change of government in May hasn’t helped, particularly as spending cuts now seem to be the order of the day. Potential customers are all delaying orders until the position of the RHI becomes clear. Manufacturers and installers are now having to lay off staff because the market has dried up because of the confusion. All that is needed is some guidance from central government to relieve the situation.
So yesterday, Chris Huhne, the Energy Secretary, gets up in parliament and delivers his first annual energy statement. Everyone connected to this small industry is holding their breath for news of the RHI. And this is what he says. “In the heating sector, I can confirm our strong commitment to action on renewable heat. The Government is considering responses to the Renewable Heat Incentive consultation and will set out detailed options following the Spending Review.”
Groans all round. That could mean anything. It certainly doesn’t sound like anything soonish. My guess is that we now won’t see any response to the RHI Consultation until sometime in 2011. By which time this small industry will be a whole lot smaller.
28 Jun 2010
Heat Pumps: troubling times
If you were to sit down and look for business ideas where there seems to be explosive growth potential, I reckon that heat pumps would pretty quickly bubble up towards the top of most peoples' lists. It's not exactly a new technology, having been around in one form or another since the 1950s, and in some territories (I'm thinking Sweden here, and maybe Switzerland) it's established as the No 1 method of providing home heating. But in the UK, it has been and remains distinctly fringe.
Now this is all set to change with the introduction of the Renewable Heat Incentive (RHI), about which I have blogged several times. The RHI promises to throw large dollops of money at people who choose to install heat pumps. Large dollops. Like enough to pay for the entire heat pump, and a good chunk of the running costs as well. Whether the RHI is a good thing or a bad thing I won't go into here, but what is indisputable is the RHI has the power to turn the home heating market upside down and make heat pumps No 1 here in the UK in a very short space of time. Which is its intention.
But right now, heat pump suppliers are having a very difficult time, because the RHI remains a consultation document and since it was launched earlier this year there has been a change of government and the new government has been very quiet (OK — completely silent) about its fate. At a time when new cuts are being announced on a daily basis, there is concern in the industry that the RHI won't see the light of day, even though the funding for it was due to be taken from our gas bills, rather than directly from the Treasury. The RHI consultation document signalled that the new subsidies would come into effect in April 2011, and that people purchasing heat pumps now would be be able to receive the payments as and when they become available. But it was only a consultation document......
So what has happened is entirely predictable. Heat pump suppliers now have interest in the product racing ahead at record levels, but no one is actually placing any orders because they are all waiting to see if the RHI is going ahead or not. So, far from booming, business is going backwards rather fast. It's nail biting time.
And against this difficult background, I keep hearing reports of unsatisfactory heat pump installations where either the heat pump fails to provide adequate levels of heating, or the electricity bills turn out to be way higher than was anticipated. Some manufacturers are getting mired in disputes with unhappy customers, and the nascent industry risks getting dragged down by adverse publicity before it's got off the ground.
It's not that the heat pumps themselves don't work. The failures seem to stem from two areas: one is that the houses in question are not nearly as energy efficient as they were designed to be, the other is that the collecting fields on ground source heat pumps are often too small, or that the ground conditions are too dry for the ground loops to work well. The first error is the fault of the builder, whilst the second is the fault of the heat pump installer, so you can guess how the blame is attributed when a dispute arises. It's messy.
When a plumber installs a conventional gas or oil fired heating system, they build in a huge margin of error. Because the additional capital costs of a larger boiler and larger radiators are not that great, it's no great cost to the plumber, and its worth it to prevent any potential disputes with unsatisfied clients. But heat pumps, especially ground source heat pumps, are expensive beasts (typical installation costs are upwards of £12,000) so there is a temptation to engineer their output far more closely to the designed demand, hence a much greater likelihood of the finished installation failing to deliver on expectations.
To avoid these problems, my suggestions would be:
• Make sure you are comparing like with like when looking at the quotations you get. Look at the heat output side of things. Don't just accept the supplier's word that their designed output will be adequate. Ask to see the calculations and ask what the margin of error is.
• Get a soil sample analysis carried out if you are going for a ground source heat pump. Tim Pullen tells me that the seasonal difference in heat draw between a dry, sandy soil and a wet, clay soil is huge - like 10w/m2 v 40w/m2. Some suppliers take this into account, many don't.
Now this is all set to change with the introduction of the Renewable Heat Incentive (RHI), about which I have blogged several times. The RHI promises to throw large dollops of money at people who choose to install heat pumps. Large dollops. Like enough to pay for the entire heat pump, and a good chunk of the running costs as well. Whether the RHI is a good thing or a bad thing I won't go into here, but what is indisputable is the RHI has the power to turn the home heating market upside down and make heat pumps No 1 here in the UK in a very short space of time. Which is its intention.
But right now, heat pump suppliers are having a very difficult time, because the RHI remains a consultation document and since it was launched earlier this year there has been a change of government and the new government has been very quiet (OK — completely silent) about its fate. At a time when new cuts are being announced on a daily basis, there is concern in the industry that the RHI won't see the light of day, even though the funding for it was due to be taken from our gas bills, rather than directly from the Treasury. The RHI consultation document signalled that the new subsidies would come into effect in April 2011, and that people purchasing heat pumps now would be be able to receive the payments as and when they become available. But it was only a consultation document......
So what has happened is entirely predictable. Heat pump suppliers now have interest in the product racing ahead at record levels, but no one is actually placing any orders because they are all waiting to see if the RHI is going ahead or not. So, far from booming, business is going backwards rather fast. It's nail biting time.
And against this difficult background, I keep hearing reports of unsatisfactory heat pump installations where either the heat pump fails to provide adequate levels of heating, or the electricity bills turn out to be way higher than was anticipated. Some manufacturers are getting mired in disputes with unhappy customers, and the nascent industry risks getting dragged down by adverse publicity before it's got off the ground.
It's not that the heat pumps themselves don't work. The failures seem to stem from two areas: one is that the houses in question are not nearly as energy efficient as they were designed to be, the other is that the collecting fields on ground source heat pumps are often too small, or that the ground conditions are too dry for the ground loops to work well. The first error is the fault of the builder, whilst the second is the fault of the heat pump installer, so you can guess how the blame is attributed when a dispute arises. It's messy.
When a plumber installs a conventional gas or oil fired heating system, they build in a huge margin of error. Because the additional capital costs of a larger boiler and larger radiators are not that great, it's no great cost to the plumber, and its worth it to prevent any potential disputes with unsatisfied clients. But heat pumps, especially ground source heat pumps, are expensive beasts (typical installation costs are upwards of £12,000) so there is a temptation to engineer their output far more closely to the designed demand, hence a much greater likelihood of the finished installation failing to deliver on expectations.
To avoid these problems, my suggestions would be:
• Make sure you are comparing like with like when looking at the quotations you get. Look at the heat output side of things. Don't just accept the supplier's word that their designed output will be adequate. Ask to see the calculations and ask what the margin of error is.
• Get a soil sample analysis carried out if you are going for a ground source heat pump. Tim Pullen tells me that the seasonal difference in heat draw between a dry, sandy soil and a wet, clay soil is huge - like 10w/m2 v 40w/m2. Some suppliers take this into account, many don't.
21 Jun 2010
Part L and the Fuel Factors
If you want a good example of how contentious and how political the building regs have become, then the fuel factors are a great example.
The aim of Part L is to make our buildings more energy efficient. And the aim of energy efficiency is to reduce carbon emissions. But they are not quite one and the same thing, because one of the big imponderables about energy efficiency is the choice of fuel you use for heating. Each available fuel has a known carbon intensity, conventionally expressed as kilograms of carbon dioxide released for every kilowatt-hour burned. Or kg Co2/kWh, if you like abbreviations.
Now if carbon reduction was your sole aim, you could simply switch to a very low carbon fuel — we are talking biomass here, wood chips, pellets or logs — and not give two hoots about all this energy efficiency malarky. But that sort of seems a little illogical, doesn't it? Just because you chose to burn wood somehow shouldn't mean you can forget about double glazing and insulation. So Part L fuel factors take this into account and assume that no fuel can score better than mains gas.
But what of the alternative fuels? What if you are a rural selfbuilder and you are away from gas mains? Logically, you would think that your building plans would have to take the carbon intensity of your chosen fuel into account. And Part L does just that, via it's fuel factor table. If you want to heat with oil, you have to build to a higher standard. And if you want an electric heat pump, you need to build to a higher standard still. It's all explained in Table 1 of the new Part L, the Fuel Factor Table.
But the increased build standards don't fully reflect the carbon intensity of the various fuels and here is a natty graph to show you what the situation actually is. The true carbon intensity of each fuel relative to mains gas (as defined in SAP 2009) is in blue; the way they are each treated in Part L is in red.
The one that leaps out is electricity which is two and a half times more carbon intensive than mains gas but only gets penalised by 47% in Part L. That's still a penalty, for sure, but looked at another way, it represents (yet another?) subsidy for electric heat pumps.
Now some might argue that what is at issue here is not so much the current carbon intensity of electricity, but the future intensity. If the government's targets are met, then in a decade or so, the grid will be considerably greener than today and the carbon intensity of electricity will fall. So maybe it is justifiable to treat electricity so lightly in 2010.
But — make no mistake — the fuel factor tables don't represent the true carbon intensity of the fuels in question. They come with a very large slice of political meddling.
The aim of Part L is to make our buildings more energy efficient. And the aim of energy efficiency is to reduce carbon emissions. But they are not quite one and the same thing, because one of the big imponderables about energy efficiency is the choice of fuel you use for heating. Each available fuel has a known carbon intensity, conventionally expressed as kilograms of carbon dioxide released for every kilowatt-hour burned. Or kg Co2/kWh, if you like abbreviations.
Now if carbon reduction was your sole aim, you could simply switch to a very low carbon fuel — we are talking biomass here, wood chips, pellets or logs — and not give two hoots about all this energy efficiency malarky. But that sort of seems a little illogical, doesn't it? Just because you chose to burn wood somehow shouldn't mean you can forget about double glazing and insulation. So Part L fuel factors take this into account and assume that no fuel can score better than mains gas.
But what of the alternative fuels? What if you are a rural selfbuilder and you are away from gas mains? Logically, you would think that your building plans would have to take the carbon intensity of your chosen fuel into account. And Part L does just that, via it's fuel factor table. If you want to heat with oil, you have to build to a higher standard. And if you want an electric heat pump, you need to build to a higher standard still. It's all explained in Table 1 of the new Part L, the Fuel Factor Table.
But the increased build standards don't fully reflect the carbon intensity of the various fuels and here is a natty graph to show you what the situation actually is. The true carbon intensity of each fuel relative to mains gas (as defined in SAP 2009) is in blue; the way they are each treated in Part L is in red.
The one that leaps out is electricity which is two and a half times more carbon intensive than mains gas but only gets penalised by 47% in Part L. That's still a penalty, for sure, but looked at another way, it represents (yet another?) subsidy for electric heat pumps.
Now some might argue that what is at issue here is not so much the current carbon intensity of electricity, but the future intensity. If the government's targets are met, then in a decade or so, the grid will be considerably greener than today and the carbon intensity of electricity will fall. So maybe it is justifiable to treat electricity so lightly in 2010.
But — make no mistake — the fuel factor tables don't represent the true carbon intensity of the fuels in question. They come with a very large slice of political meddling.
11 Mar 2010
Is David MacKay becoming part of the problem?
Ever since Without Hot Air first hit the scene in 2008, Professor David MacKay has been the Man of the Moment. If you haven't yet read the book - which is available online as a pdf for free - then you should, because it's a great read. Bright. Cogent. And to the point. And very Cambridge, in the way that Cambridge has become a centre of excellence for the understanding of climate change. You don't find many sceptics in Cambridge - just pointy-heads and loads of nerds clever enough to make out what is going on in our atmosphere. Mackay is a pointy head par excellence but one who has the ability to explain it all to mere mortals who don't happen to inhabit one of Cambridge's rarefied quadrangles.But recently I have begun to hear dark mutterings about Mackay's new found influence with government, and this has now turned up in the comments column on my blog. Now I've no reason to attack MacKay - why he's even written something nice about me on his blog once (as far back as March 9 2008)- and he seems like a pretty good bloke from all I can see and hear (I've never met him). But it seems people are upset that since he took the Queen's Shilling and became Chief Scientific Advisor of the Department of Energy and Climate Change in September 2009, he has used his new found influence to promote air source heat pumps as the answer to our problems.
"While in theory ground-source heat pumps might have better performance than air-source, because the ground temperature is usually closer than the air temperature to the indoor temperature, in practice an air-source heat pump might be the best and simplest choice," he writes in his book.
And yet there a dozens of knowledgeable people out there who are distinctly queasy about air source heat pumps and think they may just make matters worse, especially if people rip out their old boilers and switch to ASHP ASAP. But you have to do the maths in a little more detail than he has done to work out the difference between theoretical and actual performance. Or just listen to David Strong for a few minutes (something I had the pleasure of doing in Cambridge last night).
Yet ASHP has been installed as one of the primary beneficiaries of the Renewable Heat Incentive. Conspiracy theorists detect the hand of David Mackay in designing this incentive - what else would DECC's Chief Scientific Officer do?
So it would be good to know just what has been going on here. MacKay has come a long way very fast — he only completed his book in September 2008 — and it would be unlikely that it didn't contain one or two errors and omissions. The worry is that he's just been a bit too rushed in all this, and that he simply hasn't had time to get up to speed on the critical issues.
For lovers of irony, you can't help but reflect on the title of his book here. The thing about air-souce heat pumps is that, Without Hot Air, they are next to useless!
7 Mar 2010
On the Renewable Heat Incentive
If ever an idea was half-baked, it's the Renewable Heat Incentive. On Feb 26, I was at a briefing in London, given by the civil servants who have designed the scheme, and the more I heard, the more worried I became. "It's a world first in policy terms" we were told, "we are truly in uncharted territory and we need your help." Hmmm. The nice gent from the Country Landowners Association was beside himself with thanks to the men from the ministry. Need I say more?
The most revealing conversation that I had took place during the lunchbreak when the man from British Gas talked to me about the funding of this scheme. It's big. By 2020, if it goes ahead as designed, it will add something like 35% to everyone's gas bills, as it seems that's where the levy to pay for it all will be drawn from. It's designed to pay for as many as 1.7 million subsidised renewable heat installations by then, at which point it's going to be paying out over £2 billion a year.
Make no bones about it, this is a carbon tax, but one being introduced by stealth, as it will creep into our fuel bills without it ever appearing as an additional item. I don't have any objections to a carbon tax — quite the opposite — but I would like the money raised to be used wisely, and the RHI really doesn't tick that particular box.
Why not?
Put very simply, it's subsidising the wrong people to put in the wrong kit.
As it stands there are a number of iniquities in the RHI, which I think will prove to be irreconcilable with logic or fairness.
• Arbitrary barriers between competing technologies. The technologies supported are biomass, heat pumps and solar thermal. Anything to do with fossil fuel is unacceptable. This however hides a very inconvenient fact that electricity is itself mostly derived from fossil fuels, and that unless your heat pump is set up really well, there is every chance that you will end up burning more fossil fuel (indirectly) if you switch from oil or gas to an electric heat pump. And the biomass offering is inconsistent. It seems some forms of biomass burning will receive a subsidy whilst others will not. Most clearly shown over the distinction between wood stoves, wood stove-boilers and pellet boilers. And whether or not they can (or should) have back-up boiler systems in place. As it stands, it looks like pellet boilers are IN but wood stove-boilers are OUT. It's not as if pellet boilers are fundamentally better than wood stoves with backboilers: many people can incorporate wood stoves in the homes, but have nowhere to put a pellet boiler (which needs utility space, and lots of it - QED you have to be wealthy to have a pellet boiler - it's not just a question of cost, it's also having the space).
• Deeming. Unlike the equipment being installed under the Feed-in-Tariffs (the output of which can all be metered), you can't meter the output from home heating appliances. So you calculate what it might be (using SAP, a home energy estimator). But deeming is really nothing different to a capital grant spread out over a number of payments. The crucial link between performance and reward, which is a key feature of Feed-in-Tariffs is broken. Therefore mediocrity is rewarded the same as excellence.
• The supported technologies are rewarded on a financial basis. The more expensive an installation, the more money gets thrown at it. Whether or not it actually saves any carbon, or even saves any money to the end user, is not part of the calculation. So if it's IN, its paid for at full market rate plus a calculated return of 12% (though only 6% for solar panels - a distinction I remain puzzled by). If it's OUT, then no money is available.
• Thus it stops dead any innovation in technologies that lie outside the grant-aided scheme. It also stops innovation involving a more complex interaction of techniques - cf heat recovery ventilation that incorporates an air source heat pump.
• It's not at all clear why biomass should receive a subsidy. Is it truly a renewable fuel? It pumps just as much CO2 into the atmosphere as gas. It's only renewable in the sense that we can grow more of it, which we can't with gas. If biomass is to receive a subsidy, it should be for delaying the point in the cycle where it gets burned, not for burning it. Plus biomass boilers are only ever going to be available to a very small minority of people (who just happen to have large houses!).
• Switching from fossil fuel to electricity for home heating. Again, it's none too clear that this is a wise move. Until the grid becomes much greener, the net result of the RHI may well be to push up carbon emissions. With large question marks hanging over the future of electricity production in this country, and whether we will have an infrastructure that can cope with the current demand in a few years time, why are we loading yet further demand onto the system?
• Which leaves solar thermal. The one technology here which is truly renewable. But it only gets a subsidy worth half as much as heat pumps and biomass, despite it being much cheaper to install, and despite it being open to a far wider section of the population. A strange decision if ever!
• It all points to a failure on the part of central government to introduce a clear and structured carbon tax on fossil fuel consumption, which is the logical way to approach this problem. OK, I know the reason for this: it is said to be politically impossible, and no other country has tried to do it either, and now the electorate don't believe in global warming in any event. All good points. But if you don't address it, then you end up with half-baked incentives like this, which are dressed up to look progressive but end up being very expensive to administer and yet they don't begin to tackle the problem facing us.
The most revealing conversation that I had took place during the lunchbreak when the man from British Gas talked to me about the funding of this scheme. It's big. By 2020, if it goes ahead as designed, it will add something like 35% to everyone's gas bills, as it seems that's where the levy to pay for it all will be drawn from. It's designed to pay for as many as 1.7 million subsidised renewable heat installations by then, at which point it's going to be paying out over £2 billion a year.
Make no bones about it, this is a carbon tax, but one being introduced by stealth, as it will creep into our fuel bills without it ever appearing as an additional item. I don't have any objections to a carbon tax — quite the opposite — but I would like the money raised to be used wisely, and the RHI really doesn't tick that particular box.
Why not?
Put very simply, it's subsidising the wrong people to put in the wrong kit.
As it stands there are a number of iniquities in the RHI, which I think will prove to be irreconcilable with logic or fairness.
• Arbitrary barriers between competing technologies. The technologies supported are biomass, heat pumps and solar thermal. Anything to do with fossil fuel is unacceptable. This however hides a very inconvenient fact that electricity is itself mostly derived from fossil fuels, and that unless your heat pump is set up really well, there is every chance that you will end up burning more fossil fuel (indirectly) if you switch from oil or gas to an electric heat pump. And the biomass offering is inconsistent. It seems some forms of biomass burning will receive a subsidy whilst others will not. Most clearly shown over the distinction between wood stoves, wood stove-boilers and pellet boilers. And whether or not they can (or should) have back-up boiler systems in place. As it stands, it looks like pellet boilers are IN but wood stove-boilers are OUT. It's not as if pellet boilers are fundamentally better than wood stoves with backboilers: many people can incorporate wood stoves in the homes, but have nowhere to put a pellet boiler (which needs utility space, and lots of it - QED you have to be wealthy to have a pellet boiler - it's not just a question of cost, it's also having the space).
• Deeming. Unlike the equipment being installed under the Feed-in-Tariffs (the output of which can all be metered), you can't meter the output from home heating appliances. So you calculate what it might be (using SAP, a home energy estimator). But deeming is really nothing different to a capital grant spread out over a number of payments. The crucial link between performance and reward, which is a key feature of Feed-in-Tariffs is broken. Therefore mediocrity is rewarded the same as excellence.
• The supported technologies are rewarded on a financial basis. The more expensive an installation, the more money gets thrown at it. Whether or not it actually saves any carbon, or even saves any money to the end user, is not part of the calculation. So if it's IN, its paid for at full market rate plus a calculated return of 12% (though only 6% for solar panels - a distinction I remain puzzled by). If it's OUT, then no money is available.
• Thus it stops dead any innovation in technologies that lie outside the grant-aided scheme. It also stops innovation involving a more complex interaction of techniques - cf heat recovery ventilation that incorporates an air source heat pump.
• It's not at all clear why biomass should receive a subsidy. Is it truly a renewable fuel? It pumps just as much CO2 into the atmosphere as gas. It's only renewable in the sense that we can grow more of it, which we can't with gas. If biomass is to receive a subsidy, it should be for delaying the point in the cycle where it gets burned, not for burning it. Plus biomass boilers are only ever going to be available to a very small minority of people (who just happen to have large houses!).
• Switching from fossil fuel to electricity for home heating. Again, it's none too clear that this is a wise move. Until the grid becomes much greener, the net result of the RHI may well be to push up carbon emissions. With large question marks hanging over the future of electricity production in this country, and whether we will have an infrastructure that can cope with the current demand in a few years time, why are we loading yet further demand onto the system?
• Which leaves solar thermal. The one technology here which is truly renewable. But it only gets a subsidy worth half as much as heat pumps and biomass, despite it being much cheaper to install, and despite it being open to a far wider section of the population. A strange decision if ever!
• It all points to a failure on the part of central government to introduce a clear and structured carbon tax on fossil fuel consumption, which is the logical way to approach this problem. OK, I know the reason for this: it is said to be politically impossible, and no other country has tried to do it either, and now the electorate don't believe in global warming in any event. All good points. But if you don't address it, then you end up with half-baked incentives like this, which are dressed up to look progressive but end up being very expensive to administer and yet they don't begin to tackle the problem facing us.
9 Feb 2010
Thoughts on the Renewable Heat Incentive
Heat pumps
On p31 of the consultation document, it states that only efficient heat pumps will be permitted. However this ignores the fact that the efficiency of a heat pump is related to the work it is being asked to do, and not simply the manufacturing standard. The standard CoP (Coefficient of Performance - the higher the figure the better) figures used by heat pump manufacturers refer to an uplift of 35°C. For every 1°C above this that the system is required to deliver, the efficiency of the heat pump system reduces by around 3%. Therefore a heat pump may have an efficiency of 4.0 when delivering hot water at 40°C (suitable for underfloor heating) but this will reduce to less than 2.0 if used to heat radiators at over 70°C. If the published efficiency of the heat pump starts at 3.0, then the actual efficiency is likely to fall below 1.5 if used to heat conventional radiators.
A heat pump needs to perform at a CoP better than 1.5 in order to match the carbon output of an A rated oil fired boiler.
As it stands, this incentive will cause oil-fired boilers (as a technology) to be abandoned, without any clear justification. Many people with radiator-based central heating systems looking to replace a boiler will be tempted to switch to a heat pump solely because of the incentive, which looks like it's going to worth around £750-£1,000 a year for 18 years. And yet, unless the heat delivery system is changed (which is unlikely because it would be expensive and disruptive), the energy and carbon burned will actually increase, compared to an A rated oil-fired boiler. For this reason, air source heat pumps, in particular, are ill suited to replacing domestic boilers. There seems little logic in incentivising people to install them instead of efficient fossil-fuel boilers.
Insulation
Bearing this in mind, why shouldn't this incentive scheme be extended into areas where it has the capability to make a much more meaningful contribution to reducing carbon emissions? How about extending it to people undertaking significant energy efficiency upgrades, way beyond topping up loft insulation and adding cavity wall insulation? The cost bringing a 20th century (or older) house up to modern standards (something akin to the Passive House standard for refurbishment, or Energy Savings Trust A rating) is far greater than the cost of installing a heat pump. Estimates vary from around £12,000 up to £40,000 (if glazing is to be included as well). The carbon savings are also much greater, however there is no financial incentive other than making savings on fuel bills. As it stands, the payback on this type of work extends to many decades.
The UK Green Building Council is putting forward a Pay As You Save Scheme, whereby lenders will be encouraged to make loans to undertake such improvements and in exchange the repayments would be paid for from the savings from lower fuel bills. Such a scheme enjoys no official backing as yet. Why not add some element of subsidy to it by adding such refurbishment to list of "technologies" which the Renewable Heat Incentive is designed to reward?
On p31 of the consultation document, it states that only efficient heat pumps will be permitted. However this ignores the fact that the efficiency of a heat pump is related to the work it is being asked to do, and not simply the manufacturing standard. The standard CoP (Coefficient of Performance - the higher the figure the better) figures used by heat pump manufacturers refer to an uplift of 35°C. For every 1°C above this that the system is required to deliver, the efficiency of the heat pump system reduces by around 3%. Therefore a heat pump may have an efficiency of 4.0 when delivering hot water at 40°C (suitable for underfloor heating) but this will reduce to less than 2.0 if used to heat radiators at over 70°C. If the published efficiency of the heat pump starts at 3.0, then the actual efficiency is likely to fall below 1.5 if used to heat conventional radiators.
A heat pump needs to perform at a CoP better than 1.5 in order to match the carbon output of an A rated oil fired boiler.
As it stands, this incentive will cause oil-fired boilers (as a technology) to be abandoned, without any clear justification. Many people with radiator-based central heating systems looking to replace a boiler will be tempted to switch to a heat pump solely because of the incentive, which looks like it's going to worth around £750-£1,000 a year for 18 years. And yet, unless the heat delivery system is changed (which is unlikely because it would be expensive and disruptive), the energy and carbon burned will actually increase, compared to an A rated oil-fired boiler. For this reason, air source heat pumps, in particular, are ill suited to replacing domestic boilers. There seems little logic in incentivising people to install them instead of efficient fossil-fuel boilers.
Insulation
Bearing this in mind, why shouldn't this incentive scheme be extended into areas where it has the capability to make a much more meaningful contribution to reducing carbon emissions? How about extending it to people undertaking significant energy efficiency upgrades, way beyond topping up loft insulation and adding cavity wall insulation? The cost bringing a 20th century (or older) house up to modern standards (something akin to the Passive House standard for refurbishment, or Energy Savings Trust A rating) is far greater than the cost of installing a heat pump. Estimates vary from around £12,000 up to £40,000 (if glazing is to be included as well). The carbon savings are also much greater, however there is no financial incentive other than making savings on fuel bills. As it stands, the payback on this type of work extends to many decades.
The UK Green Building Council is putting forward a Pay As You Save Scheme, whereby lenders will be encouraged to make loans to undertake such improvements and in exchange the repayments would be paid for from the savings from lower fuel bills. Such a scheme enjoys no official backing as yet. Why not add some element of subsidy to it by adding such refurbishment to list of "technologies" which the Renewable Heat Incentive is designed to reward?
3 Feb 2010
More on Feed-in Tariffs
Yesterday I had the pleasure of reading through the two documents that the Department of Energy and Climate Change put on their website on Monday (Feb 1st). The first was the government's response to the Feed-in Tariffs consultation, which sets the rates for the tariffs for electricity generating technologies, principally PV, wind, hydro and micro-CHP. These feed-in tariffs are due to come into effect this April, but will apply to anyone who has fitted one of these technologies since July 2009, when the decision to switch to feed-in tariffs was made. There are no major changes to be found in the finished document, though the rates have been adjusted a little.
Feed-in Tariffs
What these feed-in tariffs essentially do is strip away the initial capital subsidies which have existed up till now and replace them with annual payments based on how much electricity you have produced. The amount depends on the technology. PV is very expensive to install and therefore gets a high rate of return, as much as 41.3p per kWh for 25 years for small retrofit installations. MicroCHP is much cheaper and therefore attracts a smaller subsidy — 10p per kWh for just ten years. The payments will be index linked. The amount you get paid will depend on what your meter says you have produced. You don't have to export all or any of this electricity to the grid, but if you do, you will get an additional 3p per kWh for your pains.
You'll have to sign a contract to say that you will keep the plant in good repair, and if you sell up and move house, the new owner collects the Feed-in Tariff. The rates paid are guaranteed for the duration of the contract, so in some respects this is a bit like buying index-linked gilts. How does it compare as an investment?
There is a worked example on page 33 showing how it might work with a small PV unit retrofitted onto a detached house. It assumes production of 2,000kWh per annum from the PV array on a house consuming 4,500kWh per annum. The income comes in via three different methods
1. The 2,000kWh produced by the PV attracts 41.3p/kWh or £826 per annum
2. It is assumed that half this amount is exported to the grid, which attracts an additional 3p/kWh or £30 per annum
3. The other half is consumed in the house which saves having to buy 1,000kWh at 13p/kWh from the electricity supplier, a saving of £130.
Combine these and the total income is £986 per annum. The question is, how much would this all cost to install? You'd probably need at 3kW system in order to generate 2,000kWh/annum - depends of course on your location and orientation. That's around 24m2, and the cost would be around £20,000 to install. So that's a return of around 5% for your investment (i.e. £1,000 a year for a £20,000 investment). With index linked gilts currently yielding just over 2%, that leaves three/fifths of the payment/savings to cover writing off the capital cost of the installation. That's £600 a year for 25 years = £15,000. That's not incredibly attractive, but it should be relatively safe. In theory, these contracts should be as safe as gilts (which are said to be the safest of all investments because they are government guaranteed), but in practice a future government might renege on the contract if it became politically expedient. An in addition, there would be added costs not factored into the equation. Servicing for one, insurance for another. With PV costing rather more than lead, there must be a risk that the arrays would get stolen, or may get damaged by hail or vandalism. There is also the issue of whether or not installing renewable technologies in the home really will add to the capital value of the house when you come to sell.
So the feed-in tariffs are an improvement on the lacklustre capital subsidies that have existed in the UK up till now, but they are still not the sort of eye watering investment opportunity that will get the City Boys throwing up PV on their roofs to make a quick buck. In reality, this is still only going to appeal to enthusiasts.
Having said that, I met one in Switzerland last week who had bought 800m2 of PV and installed it himself on the roof of a cattle shed belonging to a nearby farmer. 800m2! That'll be nearly a million quid's worth. And all because of their feed-in tariff.
Renewable Heat Incentive
The second document is the consultation for the Renewable Heat Incentive, which is similar to the feed-in tariff but for heat producing technologies, principally solar thermal, heat pumps and biomass boilers. It once again comes with a table of tariffs:
• Solar thermal to get 18p/kWh for 20 years
• Air source heat pumps to get 7.5p/kWh for 18 years
• Ground source heat pumps to get 7p/kWh for 23 years
• Solid biomass to get 9p/kWh for 15 years
There are some major differences between these subsidies and the Feed-in Tariffs. Firstly, the output of the units will be assumed rather than metered. Their word for it is deemed. This to me immediately presents a major problem, because it will be assumed that the installations will be working as designed. A lot of cheap and inadequate systems may end up being installed in order to harvest the subsidy. And, in particular, heat pumps may get installed into poorly insulated homes where they will not really be up to the job in hand.
More on this soon, but if this incentive scheme comes into effect (on the projected date of April 2011) it will effectively sound the death knell for conventional oil fired boilers which are already struggling to compete with heat pumps. This scheme will grant you around £1,000 a year for installing a heat pump. There is one ray of hope for the oil fired boiler makers and that is called FAME, which stands for fatty acid methyl ester. It's a biofuel produced from vegetable oil which can be blended with heating oil for use in domestic boilers. The paper suggests that an oil boiler could be converted to burn FAME and therefore obtain a subsidy, but details here are sketchy.
Feed-in Tariffs
What these feed-in tariffs essentially do is strip away the initial capital subsidies which have existed up till now and replace them with annual payments based on how much electricity you have produced. The amount depends on the technology. PV is very expensive to install and therefore gets a high rate of return, as much as 41.3p per kWh for 25 years for small retrofit installations. MicroCHP is much cheaper and therefore attracts a smaller subsidy — 10p per kWh for just ten years. The payments will be index linked. The amount you get paid will depend on what your meter says you have produced. You don't have to export all or any of this electricity to the grid, but if you do, you will get an additional 3p per kWh for your pains.
You'll have to sign a contract to say that you will keep the plant in good repair, and if you sell up and move house, the new owner collects the Feed-in Tariff. The rates paid are guaranteed for the duration of the contract, so in some respects this is a bit like buying index-linked gilts. How does it compare as an investment?
There is a worked example on page 33 showing how it might work with a small PV unit retrofitted onto a detached house. It assumes production of 2,000kWh per annum from the PV array on a house consuming 4,500kWh per annum. The income comes in via three different methods
1. The 2,000kWh produced by the PV attracts 41.3p/kWh or £826 per annum
2. It is assumed that half this amount is exported to the grid, which attracts an additional 3p/kWh or £30 per annum
3. The other half is consumed in the house which saves having to buy 1,000kWh at 13p/kWh from the electricity supplier, a saving of £130.
Combine these and the total income is £986 per annum. The question is, how much would this all cost to install? You'd probably need at 3kW system in order to generate 2,000kWh/annum - depends of course on your location and orientation. That's around 24m2, and the cost would be around £20,000 to install. So that's a return of around 5% for your investment (i.e. £1,000 a year for a £20,000 investment). With index linked gilts currently yielding just over 2%, that leaves three/fifths of the payment/savings to cover writing off the capital cost of the installation. That's £600 a year for 25 years = £15,000. That's not incredibly attractive, but it should be relatively safe. In theory, these contracts should be as safe as gilts (which are said to be the safest of all investments because they are government guaranteed), but in practice a future government might renege on the contract if it became politically expedient. An in addition, there would be added costs not factored into the equation. Servicing for one, insurance for another. With PV costing rather more than lead, there must be a risk that the arrays would get stolen, or may get damaged by hail or vandalism. There is also the issue of whether or not installing renewable technologies in the home really will add to the capital value of the house when you come to sell.
So the feed-in tariffs are an improvement on the lacklustre capital subsidies that have existed in the UK up till now, but they are still not the sort of eye watering investment opportunity that will get the City Boys throwing up PV on their roofs to make a quick buck. In reality, this is still only going to appeal to enthusiasts.
Having said that, I met one in Switzerland last week who had bought 800m2 of PV and installed it himself on the roof of a cattle shed belonging to a nearby farmer. 800m2! That'll be nearly a million quid's worth. And all because of their feed-in tariff.
Renewable Heat Incentive
The second document is the consultation for the Renewable Heat Incentive, which is similar to the feed-in tariff but for heat producing technologies, principally solar thermal, heat pumps and biomass boilers. It once again comes with a table of tariffs:
• Solar thermal to get 18p/kWh for 20 years
• Air source heat pumps to get 7.5p/kWh for 18 years
• Ground source heat pumps to get 7p/kWh for 23 years
• Solid biomass to get 9p/kWh for 15 years
There are some major differences between these subsidies and the Feed-in Tariffs. Firstly, the output of the units will be assumed rather than metered. Their word for it is deemed. This to me immediately presents a major problem, because it will be assumed that the installations will be working as designed. A lot of cheap and inadequate systems may end up being installed in order to harvest the subsidy. And, in particular, heat pumps may get installed into poorly insulated homes where they will not really be up to the job in hand.
More on this soon, but if this incentive scheme comes into effect (on the projected date of April 2011) it will effectively sound the death knell for conventional oil fired boilers which are already struggling to compete with heat pumps. This scheme will grant you around £1,000 a year for installing a heat pump. There is one ray of hope for the oil fired boiler makers and that is called FAME, which stands for fatty acid methyl ester. It's a biofuel produced from vegetable oil which can be blended with heating oil for use in domestic boilers. The paper suggests that an oil boiler could be converted to burn FAME and therefore obtain a subsidy, but details here are sketchy.
2 Feb 2010
The Green Bling Tariffs
The Department of Energy and Climate Change has now published the final version of the Feed-in-Tariffs which are due to come into effect in April. The document is here. It has also published consultation, including indicative pricing, on the second leg of this subsidy, the Renewable Heat Incentive, which covers heat pumps, solar thermal and biomass.
I have yet to work out the full implications, but I suspect that the Renewable Heat Incentive will tilt the balance firmly in favour of heat pumps for anyone considering how to heat a house.
I have yet to work out the full implications, but I suspect that the Renewable Heat Incentive will tilt the balance firmly in favour of heat pumps for anyone considering how to heat a house.
3 Dec 2007
Barratt's Eco Village
Whilst Yvette Cooper and her chums would have us believe that the drive towards zero-carbon homes will transform the way we design and build houses, the reality is more likely to look something like this photo. This is Barratt’s Eco Village in Chorley near Manchester and it’s probably one of the most depressing photos of the year. For it could be any Barratt estate anywhere in the past twenty years, except that it’s got a few micro wind turbines stuck up above the rooftops. Some future we have to look forward to here.To be fair, the site has been conceived more as a test bed for zero and low carbon technologies than as an exemplar of what homes might look like. But surely the Barratt design department could have tried just a little bit harder, seeing as they knew it was going to be on view.
An article in the latest Building reports on the results of a year’s survey by the University of Manchester on the performance of five different technologies featured here at the eco-village. The results more or less confirm figures gleaned from other tests.
• Micro Wind Turbines: two different types tried: both useless, producing virtually no power at all
• Ground source heat pumps: three different ones fitted, which the manufacturers claimed would deliver a CoP (measurement of efficiency) of between 3.0 and 5.0. Average CoP achieved? Just 2.6. They work, but not as well as we are led to believe.
• Photovoltaics: three 8m2 arrays placed on three roofs. Output varied depending on orientation and angle. South facing was best (not surprisingly): a 45° one produced 1034kWh of electricity in a year. An east facing one at 60° produced 760kWh whilst another east facing one mounted at 45° produced 818kWh. These results are bang in line with expectations: no one doubts that PV arrays produce power in reasonable quantities, the problem is the cost of installing them.
• Solar thermal: comparisons were made between a 2.5m2 flat plate and a 3m2 evacuated tube, both used to heat a 180lt hot water tank. Both succeeded in doing this for the summer months: the evacuated tube could get the water to 75°C, as compared to 60°C for the flat plate collector. The researcher, Dr Tony Sung, makes an interesting point that this added performance wasn’t of any obvious value, as 60°C is plenty hot enough.
• Micro CHP: two units fitted, both Whispergens. One produced 11,000kWh of heat and 680kWh of electricity, the other 9,600kWh heat and 260kWh of electricity: the difference between them is explained by the different lifestyles of the occupants, but interesting to note that the average power:electricity ratio is 20:1, only half as good as the Carbon Trust survey results.
28 Nov 2007
Micro CHP
Combined Heat and Power (CHP) is a low carbon technology which produces both hot water and electricity. It’s been used mostly at the commercial level for some time but there is a small domestic version, known as Micro CHP.To date, it’s not been staggeringly successful. The proposition isn’t that appealing, at least as far as homeowners are concerned. You shell out about two or three times as much as your would for a gas boiler, and you get some of your electricity requirement thrown in with your hot water. Whilst large and medium sized CHP plants are doing rather well, down at the micro level things have come becalmed, especially as the only one commercially available, the gas-fired Whispergen, pictured here, has temporarily ceased production.
Thanks to the boys over at Carbon Limited who have flagged up a report from The Carbon Trust on the micro CHP. It has drawn some interesting conclusions in comparing the performance of 87 Micro CHP units with 27 condensing boilers over a four-year period.
• Key finding is that in order to operate effectively, micro CHP has to be in a situation where it can run for long periods uninterrupted. If the system cycles on and off frequently, it ends up using more electricity than it generates.
• Essentially this means that they are suitable for sites such as residential care homes and leisure centres, where there is a reasonably large and consistent hot water demand, In these instances, there can be significant savings — the report quotes 15% to 20% — relative to using condensing boilers
• But in housing, micro-CHP advantages are marginal at best. The demand has to be significant to make any savings, so it may be a runner if the house is very large or very old and uninsulated. Think listed manor houses – that sort of thing. The cut-off point identified by the report is a heat demand of more than 20,000kWh/annum, which would apply to almost all 20th century housing over 200m2 internal floor area (say five bedrooms).
• One of the main issues with today’s generation of micro CHP is that they only produce 1 unit of electrical power for every 10 units of hot water. This doesn’t match general domestic use, which is more like 1:3. Not until new technology kicks in (fuel cells anyone?) will a micro CHP plant start producing a better balance.
• Having said that, there is a good match time-wise. Peak electricity and hot water demand tend to occur at the same time (think dark winter nights), unlike technologies such as roof mounted PV arrays. So there is every chance that the electricity you produce, you will actually consume rather than having to export it to the grid at knockdown prices.
• The report also has some factoids about condensing boilers. It concludes that they achieve efficiencies about 5% less than their SEDBUK rating would suggest. And also that the electrical controls use large amounts of power to run the pumps, fans and control systems. Some designs are worse than others and the difference is significant. In some instances, the electrical consumption associated with condensing boilers may account for 15% of the household electricity bill.
12 Nov 2007
Pumping heat
Spent the weekend dispensing bon-mots and advice in Harrogate at the Homebuilding & Renovating show, one of six held throughout the UK each year. This year I have been delivering a short lecture on sustainable homebuilding and it has sparked some interesting questions and comments from the audience. However this Sunday it all got a little fiery when someone asked about the difference between air source and ground source heat pumps and whether either made sense for his building project. Rather like the output from these heat pumps, my response was just a little lukewarm.
What I specifically said was that heat pumps don’t make much sense if mains gas is available but that there should be a reasonable payback against oil. “You are doing well if you get a Coefficient of Performance of more than 3.0,” I said. I have been consistently saying this for some time now and at least one heat pump manufacturer, Kensa, seem happy to agree with me.
But up stands this man in the audience who said that heat pumps could now deliver over 6.0 — i.e. twice as much heat output for the power input. Before I could stop myself, I blurted out “That’s rubbish.” It obviously hit a nerve, because he stood up and started getting shirty with me. “What do I know about it” sort of stuff. I have no idea who he was but can only guess he was working for one of the many heat pump suppliers exhibiting at the show.
This made me go all defensive and I started quoting a couple of studies back at him that showed that heat pumps often don’t deliver what manufacturers claim. If only to prove that I do know something about it, if not exactly ranking at world expert status. This of course made matters worse and our man turns around and walks out of the seminar theatre in an act of brazen defiance.
You could have heard a pin drop. Normally, these events pass by without any rancour at all and everything is sweetness and light from start to finish. Here there was a definite feeling that someone thought I that I was being out of order and should be upbraided.
What I think this shows is that the heat pump market is maturing fast, perhaps a little too fast. By all means consider the merits of using a heat pump, but don’t get sucked in by the hype, and beware claims of extraordinary efficiencies achieved.
What I specifically said was that heat pumps don’t make much sense if mains gas is available but that there should be a reasonable payback against oil. “You are doing well if you get a Coefficient of Performance of more than 3.0,” I said. I have been consistently saying this for some time now and at least one heat pump manufacturer, Kensa, seem happy to agree with me.
But up stands this man in the audience who said that heat pumps could now deliver over 6.0 — i.e. twice as much heat output for the power input. Before I could stop myself, I blurted out “That’s rubbish.” It obviously hit a nerve, because he stood up and started getting shirty with me. “What do I know about it” sort of stuff. I have no idea who he was but can only guess he was working for one of the many heat pump suppliers exhibiting at the show.
This made me go all defensive and I started quoting a couple of studies back at him that showed that heat pumps often don’t deliver what manufacturers claim. If only to prove that I do know something about it, if not exactly ranking at world expert status. This of course made matters worse and our man turns around and walks out of the seminar theatre in an act of brazen defiance.
You could have heard a pin drop. Normally, these events pass by without any rancour at all and everything is sweetness and light from start to finish. Here there was a definite feeling that someone thought I that I was being out of order and should be upbraided.
What I think this shows is that the heat pump market is maturing fast, perhaps a little too fast. By all means consider the merits of using a heat pump, but don’t get sucked in by the hype, and beware claims of extraordinary efficiencies achieved.
21 Aug 2007
Carbon Accounting in Electricity
In order to make sensible decisions about how to reduce CO2 emissions, you need good data on what those emissions actually are. In essence, you need to create a robust accounting system, built out of units of CO2, not to mention other greenhouse gases. There will be both a profit and loss account – energy in use – and a balance sheet – embodied energy in buildings and plant. In an ideal world, these carbon units could be linked to money and you could apply a cost-effectiveness filter across everything.
But the basic data isn’t yet in place. Or, to put it another way, there are still wide disparities in attempting to work out just how much CO2 is being emitted.
Take electricity consumption. It’s a complex beast because it is derived from a variety of sources, some carbon rich (oil, gas, coal) some almost carbon-free (nuclear, renewables). Plus it gets distributed over huge areas and undergoes transmission losses and power station inefficiencies. How can you attribute a single figure to the CO2 content of electricity? Well, we do. It is routinely rated in the UK as emitting 0.43kgCO2/kwh, just over twice as much as mains gas, and this is the figure used to calculate the CO2 emissions of electrical appliances, including heat pumps.
A long and involved thread on the AECB forum looked into just how accurate this 0.43 figure actually is. It turns out it was set in 1998 at a time when the CO2 content of electricity was falling because of the dash-for-gas. It never got down to 0.43, but it was thought that this was a good figure to use because, over a decade or so, it was hoped that the CO2 content might fall to somewhere close, and so it was a good basis to plan electrical installations on. The current figure, according to DEFRA, is actually 0.52 and, worryingly, it’s been going up not down in recent years as coal fired power stations have been coming back on line. This figure also takes no account of transmission losses, nor of embodied energy costs in power stations, nor extraction/transportation costs of coal and gas. It could, in reality be much higher than 0.52kgCO2/kWh. Some comments even set it above 1.00kgCO2/kWh. How can we hope to make sensible planning decisions about whether to install kit like heat pumps unless we can be sure that the raw data on electricity use is accurate?
It is yet another puzzle in this complex web we are weaving. It seems to me to be an increasingly important issue that is not being given the attention it deserves. We are being expected to make ball-achingly expensive decisions about future CO2 emissions and energy paybacks, but there are still huge question marks hanging over the accuracy of the data we are using.
But the basic data isn’t yet in place. Or, to put it another way, there are still wide disparities in attempting to work out just how much CO2 is being emitted.
Take electricity consumption. It’s a complex beast because it is derived from a variety of sources, some carbon rich (oil, gas, coal) some almost carbon-free (nuclear, renewables). Plus it gets distributed over huge areas and undergoes transmission losses and power station inefficiencies. How can you attribute a single figure to the CO2 content of electricity? Well, we do. It is routinely rated in the UK as emitting 0.43kgCO2/kwh, just over twice as much as mains gas, and this is the figure used to calculate the CO2 emissions of electrical appliances, including heat pumps.
A long and involved thread on the AECB forum looked into just how accurate this 0.43 figure actually is. It turns out it was set in 1998 at a time when the CO2 content of electricity was falling because of the dash-for-gas. It never got down to 0.43, but it was thought that this was a good figure to use because, over a decade or so, it was hoped that the CO2 content might fall to somewhere close, and so it was a good basis to plan electrical installations on. The current figure, according to DEFRA, is actually 0.52 and, worryingly, it’s been going up not down in recent years as coal fired power stations have been coming back on line. This figure also takes no account of transmission losses, nor of embodied energy costs in power stations, nor extraction/transportation costs of coal and gas. It could, in reality be much higher than 0.52kgCO2/kWh. Some comments even set it above 1.00kgCO2/kWh. How can we hope to make sensible planning decisions about whether to install kit like heat pumps unless we can be sure that the raw data on electricity use is accurate?
It is yet another puzzle in this complex web we are weaving. It seems to me to be an increasingly important issue that is not being given the attention it deserves. We are being expected to make ball-achingly expensive decisions about future CO2 emissions and energy paybacks, but there are still huge question marks hanging over the accuracy of the data we are using.
11 Jul 2007
Anyone for an air source heat pump?
This man is Peter Ferguson and he'd like to sell you one. He owns and runs Trianco, the Sheffield-based, metal bashing oil-fired boiler maker. I spent a couple of hours with him on Monday, listening to his tale and sharing his dreams and aspirations.Oil boilers are a mature market. There are perhaps a million of them dotted around the country, mostly in out of the way locations where mains gas can’t reach. Each year, 60,000-odd new ones get installed, mostly as replacements. Trianco have a slug of this market, around 10%, but it’s not growing. Oil boilers, just like solid fuel boilers before them, would seem to be yesterday’s technology. Even with the recent move over to condensing boilers, there doesn’t seem to be much mileage left here for long term growth plans.
The question is what will replace them. The world and their aunt are all harping on about renewables and carbon-free or carbon-lite power systems. With climate change slowly moving centre stage, it’s hard not to conclude that this is where the future lies. But there is still a lot of doubt as to which of the new technologies will succeed and which will fall by the wayside.
Ferguson reckons he’s spotted a market gap here and thinks that Air Source Heat Pumps (ASHP) may just be the next big thing. ASHP are the smaller and lesser known relative of the ground source heat pump (GSHP) which has, in contrast, had quite a lot of attention in recent years. ASHP differs from GSHP in three crucial respects:
• it doesn’t require digging up the garden and rolling out 100s of metres of tubing
• instead it works by taking heat out of the air
• it’s cheap compared to GSHP and to all the other green power systems.
To date, people have thought of heat pumps primarily as space heating devices. Ferguson’s Eureka moment came when he saw that it would be beneficial to position ASHP against solar thermal panels, as an alternative method of delivering hot water for the tap. Instead of spending maybe £3,000 or more installing solar panels on your roof, which, if you were lucky, would deliver just over half your hot water requirements throughout the year, here is a solution which would cost half this price and which would provide all your hot water. Because it’s a heat pump, it delivers around three times the energy it requires to run it, so potentially you could draw off say your 4,000kWh of hot water (typical of a modern household of four) for an outlay of just 1250kWh, cost around £100 a year.
He is particularly interested in the small ASHP units, which are rated at 3kW output. The one in the photo I took is the larger 5kW one, so you can imagine that the 3kW one is almost half this size. Crucially, it is small enough to fit through the average loft hatch, and this in itself opens up a whole new market for heat pumps — small houses without gardens. The unit can get plumbed into the loft where the air temperature will, in any event, be a little higher than outdoors, and in about two hours a day it will be capable of delivering 150lits of hot water, enough for a couple of people. It’s not a renewable power source, as it uses electricity, but because the way heat pumps work, it will use about a third of the electricity an electric immersion heater would use, so it will deliver 6kWh of heat energy for just 2kWh of juice burned.
Will it catch on? Well, it may do. The one thing that makes Ferguson very bullish about his ActivAir heat pumps is that he can sell them for £695 + VAT. Compare that with solar panels (at around £2,500), or indeed any of the other renewable or carbon-lite technologies, and you can see that his ASHP units may well find a new market.
The downsides are that the units are a little on the noisy side to be happily operating indoors. And the recovery rate, the time taken to replenish your hot water cylinder, is rather slow. The 3kW unit would take over two hours to recover, as compared with 30 minutes for a similar-sized cylinder heated by a conventional boiler.
There is also the cost calculation to run through. Although ASHP will deliver three units the heat output for every one unit of electricity required to operate it, that electricity is always going to be more expensive than mains gas. And if the mains gas is a third of the price of mains electricity, then your cost saving vanishes. As it stands, mains gas is rather more expensive than this at the moment, but not by a lot, so the running cost saving is there, but only just. Unless of course you manage to run your ASHP unit on Economy 7, in which case it becomes very cheap to run indeed. But then you’d have it whirring away for a couple of hours every night whilst you slept. If you mounted it correctly, you wouldn’t hear a thing, but it would always be a concern that it could keep you awake.
Trianco’s ASHP units are available in larger sizes. As well as the 3kW output, there are 5kW, 7kW and 12kW. This largest size is capable of taking on GSHP as a whole house space heating solution. Many people feel that it’s got to be less efficient than GSHP because outside air temperatures are habitually lower than winter ground temperatures, but Ferguson’s units work at good efficiencies down to —3°C, which is about as cold as it gets in southern England these days. And at £1895, it is way cheaper than any GSHP unit I have come across.
At the moment, Ferguson is importing his ActivAir units from China, but has high hopes of bringing the metal bashing and assembly functions in house as sales demand rises. It’ll be fascinating to see whether he manages to establish ASHP as a serious contender for the future of home heating. It won’t be for a lack of trying.
3 Jan 2006
Just how good are heat pumps?
Over the past few weeks, the Independent has been carrying what it calls an Advertisement Promotion for Ice Energy heat pumps. It’s a full page and it appears in their Wednesday property supplement. The key feature of this promotion is a green boxed-out section which contains some data which is entitled Typical cost savings of a ground source heat pump (GSHP) against oil and gas. Here’s what it contains:• House type: 230m2 detached property in a rural location comprising 2 bathrooms, 4 bedrooms and 3 reception rooms, underfloor heating installed throughout
• Annual energy consumption: 32,400kWh, based on a heat requirement of 45W/m2 for central heating and domestic hot water
• Annual energy costs:
Oil 32,400 x 0.0357 x 1.25 = £1,446
Gas 32,400 x 0.02 x 1.25 = £810
GSHP: 8,120 x 0.07 = £568
Assumptions: heating oil costing 3.57p/kWh and boiler efficiency 75%, gas costing 2p/kWh and boiler efficiency 75%, electricity costing 7p/kWh and GSHP efficiency being 400%
There is some more stuff about how boilers only last 12 years and would need replacing before a GSHP system, which will last 25 years, but this is essentially a side issue. The central claim is that it is much cheaper to run a GSHP system than either oil or gas. It looks too good to be true. Is it?
First assumption. Will a 230m2 detached house really take 32,400kWh per annum to provide space heating and hot water? It could but if it was a newly built house and it took that much, you’d be very disappointed. We live in a 200m2 house with oil-fired heating: the house was built in 1992 to slightly above thermal envelope standards, which are much lower than those currently operating. We burn 27,700kWh/annum. Now this theoretical house is larger than ours by 15% - that makes 27,700 into 31,855kWh, very similar to Ice Energy’s figure. But, and it’s a BIG BUT, this is our consumption of oil, not our heating requirements. Ice Energy multiply this 32,400 by 1.25 to take account of a boiler running at 75% efficiency. I have an idea that our 14-year-old (and still going strong) Boulter boiler burns at around 75% efficiency, so our actual heating requirement is much less than our consumption figure.
Coupled to which, our energy bills could have been much lower still if we had built to 2002 standards. So, Ice Energy, you are over egging this particular pudding. A newish 230m2 house really shouldn’t need anything like 32,400kWh to keep warm. 20,000kWh would be much closer to the mark, and it could be much less if built green.
Second assumption. Energy costs. I think Ice Energy’s take on energy costs is pretty accurate as a snapshot of what is happening in the market as of now. What it will be like over a 25-year period is anyone’s guess but 2005 was marked by much higher oil prices, slightly higher gas prices and no change as yet in electricity prices. Logic would seem to suggest that the price ratios are currently out of equilibrium and that either oil will fall or electricity will rise.
Third assumption: the efficiencies of boilers v GSHP. They have suggested that boilers operate at around 75% efficiency. The new generation of condensing boilers are designed to operate at around 90%. They have also suggested that the efficiency of GSHP is 400% - i.e. that every unit of electricity fed into the system produces four units heat output. I think that’s high, at the top end of what we expect from GSHP. It might get to that sort of figure in spring or autumn when it’s not doing much work, but in the depths of winter it’s not going to get there. And as for heating domestic hot water, it’s never going to get there. In fact as regards hot water, GSHP is hardly any more efficient than using an immersion heater. I would have thought a more realistic assessment of GSHP efficiency would put it at between 2.5 and 3.0, say 2.8 for arguments sake.
So let’s replay the annual energy costs with my assumptions, rather than Ice Energy’s.
• House type: 230m2 detached property in a rural location comprising 2 bathrooms, 4 bedrooms and 3 reception rooms, underfloor heating installed throughout
• Annual energy consumption: 20,000kWh, based on a heat requirement of 25W/m2 for central heating and domestic hot water
• Annual energy costs:
Oil 20,000 x 0.0357 x 1.1 = £785
Gas 20,000 x 0.02 x 1.1 = £440
GSHP: 7,150 x 0.07 = £500
Assumptions: heating oil costing 3.57p/kWh and boiler efficiency 90%, gas costing 2p/kWh and boiler efficiency 90%, electricity costing 7p/kWh and GSHP efficiency being 280%
I think that’s a far more realistic appraisal of what Ice Energy and the whole GSHP industry are offering. It is cheap to run, but not phenomenally cheap. I am familiar with an Ice Energy installation where the fuel bills have been monitored and the outcome is around 36kWh/m2/annum, which would make their notional 230m2 house come in at 8,500kWh/annum. And you have to set against that much higher installation costs, typically around twice as much as an oil-fired boiler and maybe three times as much as a gas-fired one.
In short, GSHP is currently, at today’s fuel prices, a compelling option for home heating in a newly built house. But not nearly as compelling as Ice Energy would have us believe.
26 Oct 2005
Ground source heat pumps
The ten-year payback is here
One of the things 2005 will be remembered for is oil prices. We’ve seen the biggest hike in prices since the 1970s and the signs are that it’s not about to come back down anytime soon, if ever. Oil is the key in determining all energy prices and if the oil price heads north, then sure enough, gas and electricity will follow along in due course. But how soon, and by how much?
It’s a subject I turned my attention to last week as I sought to update my now hopelessly inadequate table on comparative heating costs, on p208 of the 6th edition. This is a key table in my book, the one that is designed to be used to make that all-important decision about how a new house should be heated. The one currently in print is based on an oil cost of 19.5p/lt (equivalent to 1.9p/kWh), a mains gas cost of 1.5p/kWh and an electricity cost of 6.5p/kWh. Yet my last tank of oil cost 34p/lt, a 75% increase.
LPG, which tracks the oil price quite closely, is up by a similar percentage, so it remains about 30% more expensive than oil. But price rises in gas and electricity are much more muted. Making direct comparisons is not easy because of the opening up of the market to dozens of suppliers, each with their own tariffs and payment terms, but the basic drift is that gas is up to around 1.8p/kWh, a 20% rise, whilst electricity still seems to be widely available for under 7p/kWh. Energy analysts seem to think that significant price rises are about to come through in these markets but they haven’t happened yet.
So what effect will this have on comparative heating costs? Mains gas will continue to be a no-brainer for home heating, if you have access to it. But a large proportion of selfbuilds don’t and here the equations are changing. In my last edition, published late 2004, oil only narrowly beat electric ground source heat pumps (GSHP) over a 20-year timespan.
The equation isn’t difficult. The GSHP costs around twice as much to install as an oil boiler plus tank but is cheaper to run because it creates around three to four units of heat for every unit of electricity burned. With oil prices at 2004 levels, it took around 20 years to recover your investment in GSHP: but with current oil prices, this payback time has fallen to less than ten years. In addition to this, the installation prices of oil boilers and tanks is set to get more expensive (though admittedly more efficient) as new legislation takes effect, whilst the market for GSHP is expanding so rapidly that prices seem to be becoming keener. Plus GSHP is still eligible for the Clear Skies grant, worth £1200.
GSHP comes with a couple of other plus points. You don’t have an unsightly oil tank in your garden and the equipment is silent and has no flue. On the minus side, it works most efficiently at heating water to relatively low temperatures, such as you would use with underfloor heating (usually 55°C). It does therefore require a good-sized hot water tank to have a decent buffer of hot water on site. And it requires garden space of at least three times the heated footprint: thus if you are hoping to heat a 150m2 house, you will need 450m2 of garden in which to run the pipe.
Currently domestic heating oil is around half the price of electricity in the UK market. If this ratio holds, then GSHP will be the heating system of choice for all new off-mains gas homes Oil heating systems will only regain their competitive advantage if the price differential returns to its historical 1:3 (oil:electricity). For that we would need to see electricity prices rising to around 10p/kWh, or oil prices falling back to 2004 levels.
One of the things 2005 will be remembered for is oil prices. We’ve seen the biggest hike in prices since the 1970s and the signs are that it’s not about to come back down anytime soon, if ever. Oil is the key in determining all energy prices and if the oil price heads north, then sure enough, gas and electricity will follow along in due course. But how soon, and by how much?
It’s a subject I turned my attention to last week as I sought to update my now hopelessly inadequate table on comparative heating costs, on p208 of the 6th edition. This is a key table in my book, the one that is designed to be used to make that all-important decision about how a new house should be heated. The one currently in print is based on an oil cost of 19.5p/lt (equivalent to 1.9p/kWh), a mains gas cost of 1.5p/kWh and an electricity cost of 6.5p/kWh. Yet my last tank of oil cost 34p/lt, a 75% increase.
LPG, which tracks the oil price quite closely, is up by a similar percentage, so it remains about 30% more expensive than oil. But price rises in gas and electricity are much more muted. Making direct comparisons is not easy because of the opening up of the market to dozens of suppliers, each with their own tariffs and payment terms, but the basic drift is that gas is up to around 1.8p/kWh, a 20% rise, whilst electricity still seems to be widely available for under 7p/kWh. Energy analysts seem to think that significant price rises are about to come through in these markets but they haven’t happened yet.
So what effect will this have on comparative heating costs? Mains gas will continue to be a no-brainer for home heating, if you have access to it. But a large proportion of selfbuilds don’t and here the equations are changing. In my last edition, published late 2004, oil only narrowly beat electric ground source heat pumps (GSHP) over a 20-year timespan.
The equation isn’t difficult. The GSHP costs around twice as much to install as an oil boiler plus tank but is cheaper to run because it creates around three to four units of heat for every unit of electricity burned. With oil prices at 2004 levels, it took around 20 years to recover your investment in GSHP: but with current oil prices, this payback time has fallen to less than ten years. In addition to this, the installation prices of oil boilers and tanks is set to get more expensive (though admittedly more efficient) as new legislation takes effect, whilst the market for GSHP is expanding so rapidly that prices seem to be becoming keener. Plus GSHP is still eligible for the Clear Skies grant, worth £1200.
GSHP comes with a couple of other plus points. You don’t have an unsightly oil tank in your garden and the equipment is silent and has no flue. On the minus side, it works most efficiently at heating water to relatively low temperatures, such as you would use with underfloor heating (usually 55°C). It does therefore require a good-sized hot water tank to have a decent buffer of hot water on site. And it requires garden space of at least three times the heated footprint: thus if you are hoping to heat a 150m2 house, you will need 450m2 of garden in which to run the pipe.
Currently domestic heating oil is around half the price of electricity in the UK market. If this ratio holds, then GSHP will be the heating system of choice for all new off-mains gas homes Oil heating systems will only regain their competitive advantage if the price differential returns to its historical 1:3 (oil:electricity). For that we would need to see electricity prices rising to around 10p/kWh, or oil prices falling back to 2004 levels.
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