31 Mar 2010

Waste not, want not

What happens to your rubbish these days? It’s a very good question, and the answers aren’t quite as straightforward as you might hope for. Over the past decade, we have all been more or less trained to separate out our waste. Most local authorities now have collections for a variety of products like paper, glass, plastics and aluminium cans. And most now try to separate organic waste (food, cardboard, garden clippings, etc) from ordinary, indestructible household waste (packaging mostly in my house at least).

Now the non-organic, non-decomposable waste used to go into landfill mostly, at least it does in Cambridgeshire, my council, although it can be incinerated to produce usable power and heat. In contrast, the green, bio-degradable waste was composted.

Cambridgeshire County Council has just spent £42 million on a gigantic waste sorter cum compost heap known as a Mechanical Biological Treatment Plant (PFI money) and you can read about it here. It’s so state-of-the-art, that it can extract the organic material from the black bin waste, and they estimate that something like 80% of the waste currently being landfilled will end up going through this MBT plant. Good news? Maybe.

Look a little bit more closely. There is an interesting sentence at the end of their guide to MBT which states: Due to the fact that the input is mixed waste, the material produced cannot be used by farmers or the public, but we hope to use the compost-like output of the MBT plant for quarry restoration, growing energy crops or as a fuel. In other words, they haven’t really got a use for all this compost yet.

Organic matter left in landfill slowly undergoes anaerobic digestion which release methane very slowly (can take up to 100 years), whereas the stuff that is fed through the MBT plant undergoes aerobic digestion very quickly. Now aerobic digestion produces CO2 instead of methane, but unfortunately both of these happen to be greenhouse gases. I know methane is something like 300 times more potent but the landfill digestion process seems to last about 300 times as long, so do they not more or less cancel each other out in terms of climate sensitivity?

So now instead of having holes in the ground filling up with untreated waste, we now have all this expensively treated but low-grade compost looking for a home because they are not allowed to give it away to farmers or the public (something to do with the old BSE scare, methinks). And they may end up incinerating it! Which, of course, they could have done in the first place without treating it.

Still, it’s a fine looking building, the size of three football pitches, and stuffed full of trommel screens, tilting vibrating plates, electro magnets, eddy current separators, not to mention targeted air jets and waste grinders. I wonder how much energy it consumes?

30 Mar 2010

Should you tip your builder?

Yesterday, I spent a happy couple of hours with Chris Towns (pictured here), a selfbuilder I had met at the Homebuilding & Renovating show at the NEC just a week beforehand. Chris is building a very modest house (about 100m2) in Greenford, West London, just a stone’s throw from the A40 as it whooshes past the Hoover Building.

You don’t really get conventional building plots for sale in London and this one is no exception. It turns out to have been purchased by his father 30-odd years ago and has lain dormant for all that time because the original planning permission had lapsed and all it had managed to achieve in the intervening years was a long and ugly planning history — it’s on a tiny corner site, next to an electricity substation.

It’s only recently that a successful permission has been won, and Chris has had the financial wherewithal to build it out. There’s nothing remarkable about this house — brick and block, uPVC windows, rendered exterior under Rosemary tiles — but there is something remarkable about the way Chris has gone about building it. He tips his builders. In all the years I have been knocking around construction, I have never heard of anyone tipping their builders, other than maybe giving them a bottle at Xmas.

Chris’s logic seems sound to me. He has spent most of his adult life — he is 54 — working as a drayman for Scottish & Newcastle. In this trade, it was commonplace to receive some small offering from his clients, after almost every drop, and it was a recognised perk of the job. “You will probably think I’m mad, but I figured that everyone who worked on my site should get a drink on me, so I routinely give some cash to all the tradesmen who spend time here.”

To date he’s spent about £85,000 on getting the house to the stage you see in this photo (essentially the shell is complete and first-fix services are just starting), and this includes a horrendous £10,000 charge paid to Thames Water for drain connections, not to mention dealing with foundations in clay which went fully 3m down. I reckon that’s a result, especially for someone who has never been involved in the building trade before and had few, if any, contacts before embarking on this selfbuild. He’s been happy to act as full-time labourer-cum-gopher, and he’s kept everyone sweet by splashing the cash at the end of the week. Tips seems to range from about £20 up to £60, depending on how long they had been on site.

I’m not saying it will work for everyone, but it certainly seems to have worked well for Chris Towns. The workmanship on display was universally excellent and the finishes looked like they were going to be superb as well. The site was tidy and immaculate, and there appeared to be no outstanding niggles. It also appeared that his subcontractors were giving him really good prices for their work.

Maybe this will be the start of a trend?

29 Mar 2010

Part G and the Water Calculator

One of the big changes coming through in the next round of building regulations is the amendments to Part G, which is due to come into effect shortly (6/4/10). Part G deals with water and it's been one of the sleepier areas of the regs to date. But this is all set to change when people designing new homes have to get their heads around the dreaded Water Efficiency Calculator for the first time.

At the moment we, as a nation, consume something like 150lts/day of potable water each in our homes. I don’t know where this figure comes from, and it certainly doesn’t relate to any home I have ever lived in recently (my personal average seems to be around 250lts/day). Moves are afoot to lower this figure — the targets are all in the Code for Sustainable Homes — and the latest version of Part G brings a figure into the equation for the first time, that figure being 125lts/person/day.

This doesn’t mean that you will only be allowed to consume 125lts/person/day, but that you must install equipment which theoretically — as if is you just happened to be the average consumer — means that you could go on living your life normally and only consume 125lts/day rather than the 150lts/day that you are currently consuming.

And what that means, of course, is that whereas up till now you just plumbed in a shower or a bath because it looked good and promised eternal happiness, now you have to perform a calculation and show it to building control who will check that you are in fact allowed to have this bit of kit.

You can find the Water Efficiency Calculator online here.

In order to get it to work, you will have to know the flow rates of your showers and taps, the capacity of your bath and the flushing volumes of your loos. You have to fill them into the calculator to work out your notional usage. And the total has to come in at under 125lts/person/day or else.

The two things that are likely to have greatest effect on these calculations are showers and baths. A shower with a very average flow rate (say under 20lts/min) is likely to find it difficult to pass the new hurdle rate. So the hunt will be on for low flow showers which still do the business, whatever that might be.

This topic came up at a seminar I attended at Ecobuild chaired by Nick Grant (or not! see Nick's post below). A woman from an “upmarket housebuilder” asked what she should do as the current batch of low-flow showers were simply unacceptable to her clients. It was suggested that the Nordic Eco shower was a possibility, and that Hansgrohe had a 6lt shower that was OK. Wolseley Sustainable Building Center promotes Mira’s Eco handset which, it says, gives a good 6lt shower. But the woman seemed unconvinced. I suggested to her that they could have swimming pools instead, as theses weren't included in the water calculator, to which she replied “Oh, they already have, but no baths and feeble showers.”

What else is new in Part G?
• G3 is being extended to include thermostatic taps on baths (max temp 48°C) because 93% of home scalding accidents occur in baths. CLG claim that a cost benefit analysis had been carried out to do this — i.e. it costs more to treat scalds than it does to fix thermostatic taps. The decision to exclude other taps (i.e. basins) was made because of the fewer number of accidents though, it was noted that in Scotland, a wider range of taps now has to be thermostatic.

• The safety features in G3, which have up till now just covered unvented hot water systems, are being extended to other water storage systems such as ordinary cylinders and thermal stores. This was controversial as it was challenged by a number of European manufacturers who sell all manner of water storage gear without all the safety paraphernalia that is required in the British market. Essentially, the kit must be modified for the UK market and must include at least two additional safety features, being temperature and pressure valves.

22 Mar 2010

The Battle of the Big Green Beasts Goes Nuclear

The renewable energy business has never seen anything like it. It’s spent years campaigning for a half-decent subsidy like they have in Germany (and at last 62 other jurisdictions, according to Wikipedia including such unlikely places as Iran). Then, just as the UK government finally ascents to the idea, up pops George Monbiot, one of our most revered green thinkers, and trashes the whole concept. In the Guardian. Ungrateful or what?

Step forward Jeremy “Solar Century” Leggett to defend the newly installed Feed-in-Tariffs. And a big welcome to Jonathan Porritt who has also been drawn into the fray. It’s all getting very entertaining. If nothing else, it’s showing us what big egos all these guys have and how easily hurt they get too. If you want to read the background, the links are here:

• The Guardian summary, including 7 posts, is here

• Porritt weighs in here

• Monbiot counters here

All the makings of a classic schism here. But underlying all this is a semi-hidden agenda, and that is whether you are pro- or anti-nuclear power. Monbiot is a nuclear convert. Leggett and Porritt remain in the pure green camp, eschewing all the maths that David MacKay and others have been throwing at us these past few years. It’s pretty much a re-run of the Roundheads v the Cavaliers.

Our dear government is backing both horses. Pressing green buttons to start new nuclear power schemes, whilst simultaneously throwing money at small-scale renewables.

And me? You want your blogger to have an opinion? Can I fence sit this one out please? No! Oh well.

Let’s take a closer look. Like Jonathan Porritt, I have “spent a happy hour reading through this four-phase battle, point by point.” But, unlike him, I didn’t find Leggett’s defence particularly compelling. Why?

• He claims that PV is getting cheaper all the time, and it won’t be long before it is as cheap as fossil-fuel based electricity – known as grid parity. But methinks he exaggerates the effect. PV is not like silicon chips, and is not subject to Moore’s Law. In fact my impression is that prices have been pretty stable over the past few years as PV manufacturing has run into capacity constraints because of rising demand from all these countries implementing Feed-in-Tariffs.

• Grid parity could, of course, be achieved by another effect, that of rising fossil fuel prices which would make conventional electricity much more expensive. That might yet happen, but it’s not a reason to subsidise PV.

• What Leggett doesn’t adequately explain is why some renewables should get bigger subsidies than others and – incidentally – none more so than PV which gets by far the most. Monbiot lays down a challenge on this one and it’s not answered. Actually, it does get answered but in a very oblique way. It seems that Leggett’s reason for a high subsidy for PV is that — basically — it’s not nuclear. He writes: “We would be crazy just to go for the technologies that happen to be the cheapest in March 2010, and it is extraordinary that an advocate of expensive nuclear like Monbiot can argue this.”

• By this logic, the more expensive the technology, the more it should be subsidised. Which is, in fact, exactly what FiTs do. Leggett seems to be suggesting that if it gets a big subsidy it will then get cheaper more quickly, but there seems no evidence for this. After 10 years of FiTs in Germany, PV is still comfortably the most expensive technology out there.

• The 50,000 jobs argument. Are these real jobs or simply subsidy harvesting jobs? If you throw billions at any enterprise, you will create tens of thousands of jobs. The test is whether they will survive the removal of the subsidies. It seems unlikely, but of course no one can say for sure. Presumably, if we hit grid parity, the subsidies stop and the jobs take-off from there. But just what if we don’t hit grid parity anytime soon.

• Where’s the money coming from? It’s a carbon tax on fossil fuels. It will be taken from everyone and given to those with the wherewithal to install PV or other renewables — i.e. the rich. Therefore, in my view, Monbiot is more or less right. The net effect will be a Robin Hood tax in reverse. Leggett tries to duck out of this one by suggesting that the levy will be so small that no one will notice. He suggests: “The average yearly cost of the feed-in tariff scheme to household levy payers is projected to be £8.50 per year to 2030.”

But that rather depends how many people take up the FiTs, doesn’t it? Now for some natty maths. Are you reading this, professors?

By Leggett’s own calculations, an “end of terrace house, 62m2” with a 2.5kW array on the roof is capable of producing 2,125kWh/annum. Let’s run with this figure.

2,125kWh would pay the lucky homeowner just under £1,000 each year for 25 years, at the agreed FiT of 41p/kWh. Now, according to Leggett, this is only going to cost us all £8.50 per year on our fuel bills. £8.50 x 25 million households equates to £212 million per annum. That’s peanuts. If everyone of these gets paid out £1,000 each year, then there will only be 212,000 schemes up and running. If that’s all that’s been done by 2020, then FiTs would be judged to be a failure, methinks. Not to mention 2030, which is the date Leggett refers to. I'll stick with 2020.

How much has Germany installed in the past ten years? This article suggests that current capacity is between 5 and 6 Gigawatts, and the take-up has been growing phenomenally quickly, by as much as 40% per annum. 5 Gigawatt capacity is equivalent to 2 million terraced roof installations, roughly ten times as much as Leggett’s £8.50 will support. Or, to put it another way, the average fuel bill will have to be £85 higher in order to pay for it. And that’s just for PV! So, if we repeat the German experience here, by 2020 we would expect our fuel bills to be positively groaning with incentive levies of one sort or another. £8.50, my arse.

These calcs sort of confirm the conversation I had the other week with the man from British Gas who reckoned the Renewable Heat Incentive would add 35% to our gas bills by 2020. It looks like FiTs will be adding a similar amount to our electricity bills.

And how much power will these 2 million rooftop installations actually produce? According to Leggett’s own estimates, if a 2.5kW array produces 2,125kWh/annum, then 2 million homes kitted out this way would produce around 4,250 Gigawatts hours. It sure sounds like a lot, until you realise that there is another unit up from this, the Terawatt, which is a 1,000 Gigawatts, and the UK consumes something like 400 terawatt hours of electricity per annum. So these 2 million roof top PV arrays will be contributing no more than 1% of the total required – if we follow the German model – by 2020. How depressing! I wish it were more, but it’s not.

So subsidising PV is a) very expensive and b) just scratching the surface. Add to it the levies for wind and hydro, and the levies for the Renewable Heat Incentive, and it’s easy to see how the effect will be to add hundreds of pounds to the typical family fuel bill by 2020. Monbiot’s point is not that a carbon tax such as this shouldn’t be applied, but that it could be spent more effectively. I think he’s right.

In fact, the more you analyse it, the more right Monbiot’s arguments seem to be. But rational analysis has been left behind because the hornet’s nest Monbiot has stirred up has little to do with renewables and FiTs, and much to do with nuclear power. It’s a topic which has always divided greens, and it looks like it’s going to continue to do for many years to come. What worries me is that Leggett and Porritt are twisting facts and figures in order to support their views. In doing so, they paint a far too rosy picture of what small-scale renewables can achieve. It’s all too reminiscent of the posturing that went on in Ken Livingstone’s London Climate Change Action Plan.

15 Mar 2010

Improving the Incentives

I keep chewing over these incentives and thinking what a missed opportunity they are. The government is at long last prepared to throw a lot of money at greening our buildings. That's the good news, and what is just as good is that this intention will, in all likelihood, survive into the new administration after the election. But having decided to press the green button for GO, they've gone and designed up a series of initiatives that hit the wrong targets.

Easy to sound ungrateful and to carp, but how could the incentives be improved? Well, it looks like Feed-in-Tariffs are in place and have to be lived with, despite being comprehensively torpedoed by George Monbiot recently. But the Renewable Heat Incentive and the Household Energy Management Strategy are still taxiing for take off and could yet be redesigned.

I think the answer is not to scrap them, but to integrate the RHI and HEMS into one combined initiative. Rather than subsidising plant, it would be better to incentivise people for undertaking energy upgrades, and not to tie this to any particular system or technology. The combined incentive could be a mixture of grant and zero- or low-interest loans - repayable on the sale of the property - and the aim would be to get all buildings up to the A standard by 2050. Incentives (and taxes on fossil fuel) would be adjusted at frequent intervals to alter the speed of the national conversion process, so that the goal is achieved to timetable.

• We already have in place a system of Energy Ratings for buildings - far from perfect, for sure, but at least it's there.

• We have plenty of advice on how to improve energy efficiency in all manner of buildings, be it by insulating or fitting low carbon heating.

• And we have building inspectors and professionals capable of both detailing and overseeing such works. For some it might be insulation, or triple glazing, for others it might be a heat pump or a biomass boiler, or an innovative ventilation system, or it could be a fuel cell or a district heating system. But critically, people would be rewarded for carrying out coherent and effective improvements. Each house, each building is different, and the most cost effective way of making them A-rated (which is close to what the aim actually is) may vary significantly.

• We have past experience of schemes like this, notably the Improvement Grant schemes, popular in the 1980s, which were used to do up much of our Victorian housing stock and which, incidentally, I first cut my building teeth on in the backstreets of Cambridge. People were awarded a grant of roughly £6,000 for undertaking around £15,000 of improvements, as specified by the council. This initiative could reward people incrementally for pushing the energy performance up the chart towards the A rating. Going from a G to an A in one leap might be very tempting with the carrot of a £25,000 grant and a £50,000 low interest loan.

• And ultimately, it would become very expensive for those who chose not to carry out improvements. The stick part of it would be higher fuel bills and maybe higher council taxes, stamp duty, etc. Easy to design a complementary set of fiscal incentives and penalties to encourage change.

It's not so far from what is happening at the moment as to be politically unachievable. Yet it is much more coherent strategy than the seemingly unrelated initiatives which have come out of DECC thus far. The FiT seems to have just been copied from Germany (just as the Germans are beginning to count the cost); the RHI looks to be modelled on the FiT because it's sort of a similar idea. In contrast, the HEMS initiative seems to have been based on a suggestion from the Green Building Council - Pay as You Save - possibly because they didn't realise that there was far more money available if only they'd asked. But in essence the RHI and the HEMS initiative are two sides of the same coin and it makes no sense to have one as a grant and the other as a loan, when what is required is an integrated approach, treating each building independently. If a heat pump improves the energy performance of a building at reasonable cost, all well and good. Subsidise it. But don't assume that heat pumps are appropriate for all situations, because they are not. This is the trap that the RHI falls into.

By the way, I have learned from well informed sources that David MacKay is not responsible for any of these recent incentives. They were all works in progress long before he was hired as Chief Scientific Officer. So the negative mutterings I have been picking up on would seem to be misplaced. I think he deserves a little longer in his role before we start passing judgments - six months is nothing. Not even Man City turn on their managers that quickly.

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.