Skip to main content
Observer Ethical awards Winners 2011

YouGen Blog

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.

Photo: Alaska Center for Energy and Power


If you have a question about anything in the above blog, please ask it in the comments section below.

Like this blog? Keep up to date with our free monthly newsletter


8 comments - read them below or add one

Gilly Jones

Gilly JonesComment left on: 23 June 2014 at 9:38 am

Hi Neilpaignton

You might find this blog useful (I've also added your comment to see if anyone else is having problems)


report abuse


neilpaigntonComment left on: 21 June 2014 at 5:55 am

I have had the Solar Thermal since April 2010.

On trying to apply for RHI as a legacy install the application would not work.

I tried over and over. 

Perhaps I have not used the correct application form online but I could not locate another. It was a case of fudging the application to make it send. Looks like a shambles from my point of view for legacy applicants. Hopefully the staff at Ofgem can pick up the application and process it anyway. Has anyone else had difficulties applying as a Legacy install?



report abuse

Cathy Debenham

Cathy DebenhamComment left on: 5 July 2012 at 10:46 am

The government's methodology for calculating return on investment anticipates that the panels will go on generating at the same rate for 35 years. I've heard of panels that were installed 20+ years ago that generate at 80%+ of original output, so would expect that to have increased over the intervening period.

report abuse


SeanDonelanComment left on: 4 July 2012 at 10:06 pm

Hi, I'm due to have a 4KW solar PV system installed tomorrow.

I spent one day last week in the company of a renewable energies expert. I work for an industrial data communication company and I set up the remote data communication system for him, on a new council office installation.

I mentioned the fact that I was due to have this system 4KW system installed, he raised his eyebrows and said "Solar panel efficiency drops off by 45% in four and a half to six years". I have since spoken to several other people "in the know" and have been told similar stories.

I would really like to know what the truth is regarding this subject. Obviously the installers will stretch the efficiency vs time out.

I will also of course be installing a data logging scheme, hoping that the data supplied by the Power One Inverter is genuine!!

Any comments would be gratefully received.

report abuse

Cathy Debenham

Cathy DebenhamComment left on: 2 July 2012 at 9:41 am

Paul - I can't agree more (although DIY would have been beyond me). There's something very satisfying about turning the boiler off for the summer too.

report abuse

Paul Hind (Secon)

Paul Hind (Secon)Comment left on: 29 June 2012 at 10:33 pm

I installed solar thermal 4 years ago DIY...Ebay is wonderful!... I loved it so much I now work in the industry as the Technical Manager for Secon Solar.

I had PV fitted last year which is wonderful, however it is no where near as interesting ...... when we have visitors to our house...sun shines..electricity is made...great..sun shines water gets very hot..."come and touch this pipe! feel how hot it is...that is all done by the sun...I's not even that sunny today"  Solar thermal is so tactile...I absolutely love it...everyone should have it.

report abuse


wookeyComment left on: 26 June 2012 at 2:50 pm

Yes, I put solar thermal in 3 years ago (DIY - it's really not complicated), and have become a huge fan. (Almost!) free hot water from the sky!

Once the distortion from the PV FIT calms down (or the RHI makes solar thermal look more attractive) I think many people who filled their roof with PV will wish they'd left a corner-space for solar thermal as it collects 3-times as much energy per m2.

Every house should have one. Ours cost £800 to fit, using the existing hot water cyclinder and supplies between 70 and 90% of our hot water (depending on how often the sun comes out, and we are prepared to wait a day or two for hot water in winter rather than turn the boiler on - if you are less flexible then the solar fraction will be lower - around 50-70%).

report abuse

Cathy Debenham

Cathy DebenhamComment left on: 26 June 2012 at 2:19 pm

Brilliant - another advocate!

report abuse

Leave a comment

You must log in to make a comment. If you haven't already registered, please sign up as a company or an individual, then come back and have your say.