An independent 2 year study conducted by Sheffield University researchers who collected data from over 2000 UK based solar PV installations has shown that 98% of these systems achieved their predicted annual generation figures, with only 2% of systems failing to reach their SAP predictions.
Dr Alistair Buckley, a university lecturer who is leading the project, said he was surprised that so many of the units were operating so well.
He said: “There are basically three main technology types that have been deployed in the UK, and they are all working well - that is ‘to spec’. They do what they say on the tin most of the time.
“About 2% of systems we have data for are clearly under-performing, all the rest fall within a broad distribution with the obvious factors such as local climate and roof orientation controlling the energy yield. We would have expected more systems to be under-performing - but it seems that the UK weather, with its lack of direct sunshine, actually makes installations less sensitive to orientation than might be expected.”
Who is responsible for installing the 2% underperforming systems?
Leeds Solar have seen some of the 2% underperforming systems, and they've all been vastly overpriced installations carried out by flashy sounding national companies that use networks of hard selling shiny suited sales people to carry out their 'survey's and 'system designs', then entirely ignore the fact there is a massive chimney directly to the south of the system that will shade it all day long when it comes to producing their performance estimates.... and then they deliberately go bust before the liability claims can come rolling in.
Avoid being part of the 2% stuck with mis-sold solar systems by taking the following measures
- Only deal directly with the MCS and REAL certified solar installation company that will actually carry out the installation.
- NEVER even allow a sales rep from an unregistered marketing company through the door, cut out the middle man and buy direct from an experienced specialist local installer instead, it will almost always work out cheaper and better in the long run.
- If someone cold calls you and you decide you are interested after the call, still cancel your appointment with the cold calling company as no reputable company uses them, then do some research of your own and invite 2-3 reputable local installation companies to produce a quote for you.
- Ask any friends or neighbours with solar systems installed for recomendations, they'll usually be only too happy to recommend good companies or warn you about bad companies,
- Don't sign anything on the day unless you've already had the quote to consider in advance. Take your time to consider your options, always insist that you be left to consider a full quote in your own time before signing anything, and show any pushy sales people the door if they won't do this.
- If you have signed on the day, remember you have a 7 day cooling off period in which you are legally entitiled to cancel your contract and receive a full refund, so contact the company as soon as possible to cancel your contract and don't take no for an answer. Please don't be put off though, most solar companies are not like this, so take your time to look around for a better installation company offering you a fair price for the system then give them a ring and ask them to provide a quote if you're happy that they aren't being too pushy on the phone.
- Use a price comparison website such as compare my solar or Leeds Solar's price guide page to check you really are getting good value for money (but understand that if you have a complex roof, scaffolding or wiring then there can be a legitimate reason for your system costing a few hundred pounds more than standard).
- Avoid lead generation websites that promise to obtain 3 quotes for you in one go, some of these are operated as scams where all 3 companies that quote will always quote £2-3,000 higher than the going rate so the unsuspecting customer thinks this must be the going rate, and others will sell your lead to up to 8 companies so the whole process becomes a nightmare.
- Have a look at your roof yourself before calling a company for a quote, and see if it looks like it's going to have much shading on the area you're thinking about. If it's got a huge chimney directly south of it then maybe solar isn't going to be suitable for you, or a specialist solar company might be able to provide a suitable solution for you, but you will at least then know to ask them about it and see if they can come up with a proper solution for you.
- A proper survey will involve measurements of the roof, rafters and supports for the roof, checking of the electrical meter location, consumer unit location, whether the existing electricl system is properly bonded, and discussion about wiring runs and inverter location. Only once this has been carried out should a proper surveyor start discussion your options with you. If the surveyor doesn't check any of these points then show them the door and get a proper solar company to give you a quote instead.