My wife and I have just completed a very substantial refurb of our house, in which we have aimed throughout to maximise our contribution to reducing emissions and energy consumption. I am an accountant, and we aimed to make sensible financial decisions wherever possible; money doesn’t grow on trees for us.

We also used Parity consultants in Sutton as advisors – a useful outfit with substantial experience of eco-refurbs. The numbers are very different when you’re not starting with a new build/clean site!

Key conclusions:

1. Some decisions are very easy: LED lighting, thick loft insulation and draught reduction are no-brainers. (The lighting case was helped because we were going to fix all the ceilings and rewire throughout anyway. It cost £2,000 for top-performance Exergi LED bulbs, but at 3.6w each they’ll pay their way well inside their expected life of 25 years.)

2. Some items make a lot of sense if you’re going to have to spend on fixing old stuff anyway. In this category, we installed underfloor insulation and heating, and we had the outside of the house insulated (it already had been cavity-wall insulated), because we needed to replace the old heating system and fix the crumbling pebble-dash finish outside. We also installed two solar hot water panels as the heating system was being completely revamped anyway.

3. Ones that just don’t make any economic sense on any calculations I could produce (confirmed by Parity) were:

- ground source heat pump – so expensive to install that our (already reduced by insulation) heating bill would have only been cut by enough to pay back in over 100 years – just stupid.

- air source heat pump – cheaper to install but shorter life and high potential maintenance costs. Came in at about 60-year payback – still stupid.

- PV roof panels – even with full feed-in tariff subsidy and taking the benefit of tax saved on alternative uses for our money (feed-in revenues are tax-free), I couldn’t get better than a 16-year payback on these. However, no PV manufacturer offers more than a ten-year guarantee on the panels (ignore their misleading promises of 80% efficiency after 25 years – look at the actual guarantee!). Then the installer typically warranty the workmanship for only two years! There are way too many uncertainties here, especially when all the panels are being produced in Chinese sweatshops (yes, I know the name on them may be Japanese or German, but look behind the facade to the facts).

A key point to bear in mind: every investment you make in energy-reducing installations reduces the saving you can make form the next. By insulating well, I reckon we halve our heating bills. That means that putting in something else to halve the remaining bill takes twice as long to pay back!

Pick the low-hanging fruit first….

If one focuses soley on CO2 and costs – the way capitalists and loony climate change gurus do – then one tends to forget that I = PAT – where I is environmental impact, P is population, A is Affluence (how much damned resources and energy we use) and T is technology (more of it means more use of resources because it must reach a limit to its efficiency at some point regardless.) Since Population is critical one must note that sustainable growth, economy or sustainability or oxymorons if we continue to operate a society based on capitalism.

We provide Rights for the disabled, sick, elderly, and the population, but there are NO RIGHTS given to the FUTURE. That’s because temporal rights have not yet been absorbed into our psyche. How could a fleshy animal race like ours even contemplate such rights for their unborn?

I say the FIT and PV investment should continue. At least its a drop in the ocean, a spark that might change the way people consume energy. That might have a longer term impact. But ultimately the lack of fossil fuels will change everything we do. Give it time, the great master of our universe…give it time.