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Solar Thermal Economic Madness

I have just had a quote for a 1403kWh/a solar hot water system land on my desk - the figures are very similar to the official website which is trying to sell us the systems.

Solar water heating systems explained - benefits, costs, savings, earnings, suitability http://www.energysavingtrust.org.uk

The cost of installing a typical solar water heating system is around £4,800 (including VAT at 5%). Savings are moderate - the system could provide most of your hot water in the summer, but much less during colder weather.
For peace of mind some installation companies offer an annual service check.

You should have your system checked more thoroughly by an accredited installer every 3-7 years, or as specified by your installer. It is likely that after this period of time the anti-freeze that is used to protect your system in the winter months will need to topped up or be replaced as it breaks down over time reducing the performance of your system. Anti-freeze lasts better if the solar water system is used throughout the year and not left unused during the warmest weeks of the year. This cost of replacing the anti-freezer is usually around £100.
The other thing that your installer should check is the pump. In a well maintained system, pumps can last for ten years plus and usually cost around £90 to replace.
Based on the results of our recent field trial, typical savings from a well-installed and properly used system are £55 per year when replacing gas heating and £80 per year when replacing electric immersion heating; however, savings will vary from user to user.
Typical carbon savings are around 230kgCO2/year when replacing gas and 510kgCO2/year when replacing electric immersion heating.

Am I missing something here? £4800 to save a maximum of £80 a year, except the costs of servicing will be about £10 a year on the pump and £20 a year on antifreeze all plus labour. So the servicing will probably cost more than the savings. Life expectancy of system? 25 years?
There is a £300 grant on installation and the promise of a renewable heat incentive in the future but it all appears to be madness. All to save half a tonne of CO2 a year which I could buy for about £5.


Check this little graph out. It comes from the building research establishment's figures and gives you an idea of the payback time for different methods of cutting heating bills:


Next time you find yourself in the local surprise your friends by quizzing them on the payback time. Then watch their eyes roll to the back of their heads as if they think your'e a total lunatic.

And they haven't even mentioned the fact that you need to clean the absorber panels every so often (once a year or more) because if they get dirty/mouldy/covered in birdshite they don't work very well.

Probably they missed that off because, as it needs access to the roof, it's liable to be very costly in terms of scaffolding, Elf n'Safety, etc.

Waste of money.

Most of the ALT energy things are perfectly fine and entirely uneconomical at current energy prices if you are connected to the grid, the further you are from the grid - the more they start making sense (any by further I mean - once you have to start stringing your own power lines or getting big deliveries of propane/gas/diesel)- so if you are sitting in the dark on some godforsaken island off the Orkney's and getting a gallon of diesel shipped to you costs 50 quid per, yeah, wind makes sense. If you are in suburban london and have a gas line 30 feet away, not so much.

It's like having your own generator, it beats being the the dark, but the utilities Gigawatt class plant will always beat you in cost per X by a huge factor.

@Paul, those figures are nonsense too. They claim that an "A rated boiler" will pay for itself in 7 years and a "micro CHP plant" in 9.

Anyone who thinks those complicated, delicate boxes of electronics will actually LAST that many years is living in cloud-cuckoo land.

Ask around who's got a late-model condensing gas boiler, how old is it, are they on their second one yet, etc.

None of these things is good for more than about five years, and even before that you start to hear "Oh, you can't the parts for those old things any more".

Me, I'm sticking to the oil-fired Aga. It'll still be sitting there being hot, year after year, with nothing needed except a hoover out every summer when it's off, long after I'm gone.

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