Solar thermal and other renewable technologies: what our readers say
Posted by Cathy Debenham on 26 June 2012 at 12:05 pm
This month the stories from readers that I like best all talk about solar thermal in some way or another. During the feed-in tariff frenzy it somehow became the poor relation to solar PV, whereas before FiTs it was the better seller. What comes over loud and clear below is that once you've got solar thermal you become an advocate. I know, I'm one too.
PollyR is 62 years old and living on her own so cutting costs is a big issue for her.
"I have been prepared to invest in the technology to help me do this and to put into practice efficient ways of making the best of them (easier with the solar thermal water I find).
"I have the vacuum tube type and have been really pleased with them since they were finally installed correctly. This took the firm nearly a year, but they have since gone out of business, which is hardly surprising.
"Most years I have not needed to turn my boiler on at all during the summer - sadly not quite so good this summer. In the first year that I had them they saved me about £300 on the previous year's bill, and I am sure that this has gone up pro-rato every year since - but not yet this year.
"My PV panels I have not had for quite a year yet, but they have generated about £2 a day on average over that time. I was warned at the time that my installation (only 7 panels were possible because of the siting of the thermal panels on my roof) was 'barely economic' - but I am very happy with them."
Supersteve warns "Solar PV is very sensitive to partial shadowing - even by a telegraph pole. This is because the shadowed cell creates a bottleneck for the whole system (if all panels are wired in series - the usual configuration). A properly designed inverter will 'throttle back' to prevent damage to panels - the SMA ones do that OK. My system is only affected on late sunny evenings - not when it's generating its max anyhow.
"However, solar thermal is not thus affected - eg. a 10% shadowing will only reduce maximum performance by 10% with no risk of damage. So, if any part of a tree, telegraph pole etc. is right in front of your panels and you can't get it removed, go for thermal instead."
LJ lives in a 19th century stone cottage, and is always looking for ways to make it drier and warmer. "I have a pellet boiler in the house that does hot water on cloudy days, and the central heating, plus a wood burning stove. The solar thermal system is great, much more efficient that one we put in our last house 12 years ago.
"Our pellet stove is much cheaper than electricity (we don't have the option of mains gas) and easier to manage than the Rayburn it replaced, but it is a bit noisy. Our local pellet supplier stopped supplying, and it seems a shame to have them trucked 30 miles plus."
We love hearing about how you're getting on with your renewable energy, any problems you've encountered, how you've over come them, and any tips you have for others. You can either sign up and add a profile on the site or if you prefer, send us an email.
By Cathy Debenham
If you have a question about anything in the above blog, please ask it in the comments section below.
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