Confessions of an ignorant solar panel owner

Hi, which is currently the best (most efficient) panel available? thanx

OK, now it’s all over I have a spare moment.

Every day almost I get a card in the letterbox or email pitching solar. Often implying a ton of ‘free’.

As with lunches, I have my doubts.

The latest I look at has more industry/quality logos than an F1 champ’s cap, but what should I look for really?

Can’t help but notice the *installation costs apply in 4pt type, too, vs. savings of £941.00 (not £940 or almost a thou, but £941). Potentially.

Plus with efficiencies in solar kit going up like Moore’s Law on PCs, is there a point at which one can aim on the basis of genuine envIROI vs. subsidy supported smoke & mirrors?

Hello – just wanted to add for anyone that missed yesterday’s solar panels live Q&A, you can replay it here: http://www.which.co.uk/environment-and-saving-energy/energy/reviews-ns/solar-panels-live-qanda/, or read through the PDF transcript we’ve added to the bottom of the page.

Our experts were kept extremely busy – we were inundated by literally hundreds of questions! A big thank you to Jim Kenney of Chelsfield Solar (a recommended Which? Local solar panel installation company) and Ian Cuthbert, microgeneration manager at the Energy Saving Trust, for coming along and sharing their expertise.

Blimey, just had a phonecall now as well.

How many companies are there ‘in the area’ on this mission?

There seems a heck of a lot of money out there in support of this.

How much goes to the consumer, or to reducing GHGs, and how much into the pockets of get-rich-quick subsidy dealers will be interesting.

Well unlike many you have at least done the sums.
A saving of about £60 per year on your gas bill is about right and your estimate of around £4000 installation is also not far off the mark.
Now £4000 divided by £60 comes to a 66 year payback. Ok to be fair gas will increase over time so it will be less than 66 years but still a very long time.
You have to be some tree hugging planet saving fanatic to lash out that sort of money because a good economic deal it most certainly ain’t.

More money and Co2 could be saved by spending that £4000 on insulation to cut down on space heating energy usage and cost.

Hi – in reply to the last two posts.

Before anyone gets suspicious, yes we do install solar pv panels!

There are a lot of benefits with solar pv – there are also a lot of crazy claims by some firms. There is some free electricity – but only if you’re using it in the day when the panels are producing power.

The major benefit is through the Feed In Tariff. On systems we have installed and checked later, we find they are over-performing very slightly based on SAP 2009 calculations. If you’re seeing figures such as £941, this tends to suggest that the company quoting them is using SAP calculations – which we are supposed to use under REA guidelines. They are probably – quite correctly – following the industry’s code of conduct.

Efficiencies in panels may go up, but you can still currently only install a G83 compliant system, so a more efficient panel won’t mean you can get any more power!

Panel efficiencies are one of the most misleading things in the industry for domestic consumers who tend to get themselves obsessed by it. A 250w panel should produce 250w. A smaller panel is more efficient as it produces its power from less area. It doesn’t make it any better – you’ll still only get 250w! Low light performance is much more important, but more difficult to quantify.

There is some talk of ‘grid parity’ in the industry, where the payments back to the producer reflect the value of the power produced. A bit worrying when you consider how much electricity prices would have to rise to meet this – even as the equipment becomes cheaper.

Also, don’t forget FIT rates decrease in April ’12, making possible savings on lower priced equipment less attractive.

One thing that people may not be aware is that Inverters cease operating if the volatge coming in from your supplier is too high. The statutary voltage level is a maximum of 253 and if the volatge goes much above that the inverter ceases operating until the volts reduce. This can be very expensive if it happens during the best sunny weather. The standard meter fitted with a PV system only shows the kWh generated not the instantaneous generation. So if you have high volts your days generation may be quite low. If that seems to be lower than you would expect it is probably worth having your supply voltage checked.