Solar panel news. Solar water heating systems = Solar panels + solar energy. Solar thermal: solar power & solar hot water. Solartwin review false claims in solar heating. Solartwin review solar contracts. Which solar panel?
Smell rats if solar sales people tell you:
- Their super special solar panel performs equally well in winter. The meterological office will tell you that the December sun delivers only 10-20% of the solar energy of the June sun. In other words 80-90% of the June energy is missing. No solar collector will collect missing energy, no matter how many times it is claimed.
- Their amazing solar panel (defies the laws of physics because it) performs equally well on cloudy and dull days. The meterological office will also tell you is that if the sun is not casting a clear edged shadow, it is delivering under 30% of full power. In other words at least 70% of he sun’s energy is missing. No solar collector will collect this missing energy. Because it never got here – much of it has been sent back up into space, reflected off the clouds, miles above our heads. In reality, cloudy and dull UK / Irish days have only 5-20% of peak sunny day sunlight levels. So there will of course be much less heat delivered to your water. This is the reality. But as soon as the clouds vanish….
- That solar thermal technology will deliver all your hot water in Northern Europe. All? Unlikely. It will not, unless you live in the tropics, where the seasonal variation in sunlight level is much less than here.
- That a solar payback calculation is simple to do. In April 2010 the Tesco Solar website was ignoring pump running costs and maintenance in its rather optimistic solar payback calculations. We asked the REAL code to require a correction but Tesco are not REAL members. So nothing changed!
- Question their solar payback claims. Without some serious subsidy, a solar water heating payback of even ten years would be remarkably good. One large UK supplier describes this as including a thorough check by an engineer every 3-5 years and claims that solar payback can be as low as six years. I wonder how robustly they can support their six year claim with independent figures? My understanding is that with gas being displaced an installation would have to cost £300-£500 (about a tenth of the industry norm) in order to meet this criterion, and this calculation is with maintenance costs being ignored. Perhaps this 6 year payback is based on bundles of £5 notes being burnt in a log burner?
- That solar will do great central heating. We want central heating most because it is winter or night. It is cold at these times because of a lack of sun. Do you really want solar to overcome the fact that solar energy is missing? This is quite a lot to ask! Solar water heating is usually preferable to solar central heating. The solar water heating application avoids this inherent mismatch between supply (of sun) and demand for heating (from you). Remember that, in general, water heating accounts for about 30% of a year’s fuel bill in an old home and about 50% in a new home.
- That the more you pay the more you get. Test this. Ask for “independently validated net energy figures”. Then compare on cost per annual kilowatt hour. For complete DIY kits you should pay under £3 per kWh and for simple installations under £5 per kWh.
- Beware of vague environmental claims. Ask for “third party evidence of energy payback time”. For example if they say that your solar energy is all free, ask if the system has a mains powered pump. If it has, ask if they are expecting you to steal its electricity. for the annual pump consumption. It is typically 75 kWh per year. Ask if the system needs antifreeze replacement and confirmation that the engineer who will do it will be cycling there to save the environment (and that he or she will be doing it all for free).
- And really quiz them on specific environmental claims such as “zero carbon“, especially if they come from Solar Trade Association members. In April 2010 the discretionary REAL code formally allowed Southern Solar’s Managing Director (and STA Chairman!) to continue lying wholesale about conventional solar water heating systems by saying that solar is “truly zero carbon”. Ask the folks there is a mains elecricity supply needed. If the answer is yes then the system is low carbon. Ask if it is PV pumped (solar-electric pumped). Then it is zero carbon. Consider reporting environmental false claim cowboys to Trading Standards (and to the REAL code – they might have woken up). Other similar false claims for mains pumped solar are: “Free energy” and “free hot water” Clearly nonsense! After an extenisve Solartwin review of our competitors’ solar websites have referred over 50 such claims to the Advertising Standards Authority. Here is the article.
- That you should only buy from the Solar Trade Association. If you do this you will be buying from organisation which unfortunately boycotts some of the best zero carbon operation solar thermal innovations and which has made unsupportable claims about Legionella and the environmental performance of solar heating.
- You must sign the deal today. Many solar suppliers will allow you a week or even a month’s validity on quotes. There is no need to be rushed by some laddie on commission. Speak with an existing user. Make 100% sure that they are not in a show house and that they are not on any incentive or bonus scheme for having guests. Ask if the supplier has a full timer to take calls in the office. Ask how long they have been trading. Ask for the facts, warts and all.