Suspect claims of solar panel supplier

balsam

first4solar are advertising a 16 panel 4kW system for £4995, claiming up to 50% saving on annual electricity bill. To achieve this you would surely have to use washing/ tumble driers/cooking/heating etc only when sun is shining and producing more kWs than you are using in total at any time. Has anyone actually reduced their electricity bill by 50% having installed solar panels and how was this achieved?
Elsewhere in their advert they claim up to 60% savings on your bill which I find even more unbelievable.

Smiley_Dan

You'll get the most replies on this topic in the Green and Ethical forum.

Cardew

50% saving on your electricity bill? or 50% of the generated electricity used in the house? - the latter (xx% of generated electricity) is the usual type of claim.


It would appear from the many people who have panels and post in the Green and Ethical forum, that around 25% of generated electricity from a 4kWp system is a reasonable estimate. Given that such a system will generate between 3,200kWh to 4,000kWh pa the likely savings are in the region of £100pa.


Some people have devices(e.g. Immersun) that automatically divert spare generated capacity to the immersion heater in a Hot Water tank. However that saving should be costed at the price for heating that is normally used - e.g gas or Economy 7 electricity.

Martyn1981

balsam wrote: »

first4solar are advertising a 16 panel 4kW system for £4995, claiming up to 50% saving on annual electricity bill. To achieve this you would surely have to use washing/ tumble driers/cooking/heating etc only when sun is shining and producing more kWs than you are using in total at any time. Has anyone actually reduced their electricity bill by 50% having installed solar panels and how was this achieved?
Elsewhere in their advert they claim up to 60% savings on your bill which I find even more unbelievable.

Hiya. 50% saving on bill will depend on your consumption, and your tariff. For instance my import has dropped approx 50% from about 3,000kWh to 1,550kWh last year. But bill hasn't dropped 50% as there's also the daily standing charge. I suppose it might be possible to cut the bill in half if you're a low user and can make the most use of daytime generation.

Because the export tariff on PV systems pays out on a deemed 50% of generation, it (very thinly) implies that 50% of generation will be consumed, and therefore can be used to estimate bill savings. That's why many/most quotes suggest leccy savings based on 50% consumption of generation, but it's highly unrealistic for most.

With a little logic, and using timers to switch on devices during the day, you'll probably actually use about 30-35% of what you generate. Last year I generated 4,600 and consumed approx 1,450 = 31.5%.

Mart.

System

We use about 55 to 60% of the solar energy that we produce from our 2.115kWp system. Our electrical consumption has fallen by 1,000 kWhs/year. We are at home all day, so we have the advantage of turning things on when the sun is shining. Timer switches are better than nothing but they cannot look up and see the sun in the sky.

matelodave

I guess it's like anything you can come up with figures that are possible but for most people are difficult to achieve unless you put some effort into making it work.

We use about 70% of our electricity between November and March and the rest in the sunny months so we'd use all that we could generate in winter and about 20-25% of our generation capacity in the summer.

I keep doing the sums but I can't convince myself that screwing £5-6k on the roof is a good idea, especially as the FIT reduces and I get older. My sums are also based on where I live, my house orientation, roof angle and my realistic electricity costs (10.5pkwh rather than the 15+ that most calculators use). I'm still looking at about 9 years to pay back.

It's like anything else you need to do your own investigations to see if what you are being offered actually works for you.

Ectophile

matelodave wrote: »

I keep doing the sums but I can't convince myself that screwing £5-6k on the roof is a good idea, especially as the FIT reduces and I get older. My sums are also based on where I live, my house orientation, roof angle and my realistic electricity costs (10.5pkwh rather than the 15+ that most calculators use). I'm still looking at about 9 years to pay back.

The FIT doesn't reduce for you. Instead, it is locked in when you apply for FIT payments, and increases with inflation. Only the new customers get the lower FIT.

I looked on solar panels as a long-term investment, rather than a source of free electricity. It should take about 8 years of FITs to pay back the cost of the panels. After that, it's free money, tax free, until the panels wear out.

Cardew

balsam wrote: »

first4solar are advertising a 16 panel 4kW system for £4995, claiming up to 50% saving on annual electricity bill. To achieve this you would surely have to use washing/ tumble driers/cooking/heating etc only when sun is shining and producing more kWs than you are using in total at any time. Has anyone actually reduced their electricity bill by 50% having installed solar panels and how was this achieved?
Elsewhere in their advert they claim up to 60% savings on your bill which I find even more unbelievable.

'Up to' means anything from 1% savings upwards; so it is a perfectly reasonable statement

reeac

Ectophile wrote: »

The FIT doesn't reduce for you. Instead, it is locked in when you apply for FIT payments, and increases with inflation. Only the new customers get the lower FIT.

I looked on solar panels as a long-term investment, rather than a source of free electricity. It should take about 8 years of FITs to pay back the cost of the panels. After that, it's free money, tax free, until the panels wear out.

.
I agree. We've had our 2.2kWh system for 4years now and it's generated a very consistent 2,200 kW per annum. We bought it in the days of high capital cost/ high FITs and we reckon on a 9 year payback time followed, hopefully, by 10 or more years of tax free net income. Our import from the National Grid has reduced by about 1000kWh per annum (from ca. 3800 down to 2700 ) with no attempt on our part to maximise daytime use.

reeac

reeac wrote: »

.
I agree. We've had our 2.2kWh system for 4years now and it's generated a very consistent 2,200 kW per annum. We bought it in the days of high capital cost/ high FITs and we reckon on a 9 year payback time followed, hopefully, by 10 or more years of tax free net income. Our import from the National Grid has reduced by about 1000kWh per annum (from ca. 3800 down to 2700 ) with no attempt on our part to maximise daytime use.

. Apologies for a mix up of units in the above. It's a 2.2 kWp system which generates 2,200kWh per annum. Shouldn't type whilst eating breakfast.

Mister_G

We've had our 3kWp system (on South facing roof) for about the same amount of time, again installed when install costs and FIT were higher.
,
We seem to generate a fairly consistent 3MWh per year. Our annual consumption has dropped by about 1,500kWh (from 8,000kWh to 6,500kWh), but we do have a Solar Immersion fitted.