Payback Time

There is an interesting letter in the May edition of Homebuilding & Renovating from Jonathan Belsey, taking me to task for an article I wrote about solar panels, which appeared in the March edition.

He writes:Although the article gave a nice summary of the available technologies, my heart sank when I saw that, as usual, the author (that’s me he’s talking about) was going to focus on return on investment as the major issue of the article. Yes, even with government grants, solar water heating and power generation are expensive and it will take you many years to recoup the money that you have spent. Why is it, though, that only alternative technologies come in for this treatment from the selfbuild press? Why doesn’t your buyers guide on showers in the same issue of Homebuilding & Renovating tell me how long it would take me to earn my money back? Well, of course, for the simple reason that I will never recoup my investment on a new shower. The same can be said of most other items we build into our houses.

It’s not the first time I have heard this criticism levied. And, in truth, I have a certain amount of sympathy with it. But ultimately, it really doesn’t stack up as an argument, because everything you fit into a house serves some purpose. A shower, for instance, is designed to get you clean: there might be cheaper ways of getting yourself clean — a bowl of water, for instance — but they aren’t as good and most people would choose a shower every time. Same with doors, lights, floor covers, kitchen units and stairs: they are all there because they serve some useful purpose.

But what is the point of a solar panel if not to produce hot water or electricity? Solar hot water panels should be looked at together with boilers. When you choose a boiler, you look for something that is reasonably priced and reasonably efficient at what it does. Looks and size may come into it, just, but the choice is largely down to cost effectiveness, with a hopeful look at comparitive environmental credentials as well. Why should you judge solar hot water panels any differently? They are a supplemental heating source, not a piece of environmental sculpture. If you are rich enough to be able to ignore the commercial realities of fitting solar panels, all well and good, but the great majority of selfbuilders aren’t and they have to weigh up the costs very carefully.

So, in my book, payback time remains a critical tool with which to judge all the renewable technologies. Without such an analysis, we have no way of judging which technologies represent good value.