Solar panels.

[graduate_owner]

For what it's worth, here is my experience, although things have changed since our panels were installed. We had a 4 kW system (16 panels) installed on a shed roof as the house orientation was far from ideal I preferred that anyway, rather than having holes drilled into the slates. We get the full FIT payments because the installation was about 14 years ago. We generate an average of 3400 units based on those 14 years, and the figure does not seem to change much each year even though we were told there would be a fall off in output after a few years. The orientation is South East, and location is mid to West Wales. At the time we didn't know if it would be a good investment because it was a new scheme but it has turned out to be excellent and I wish I had installed a larger system. I have an device which diverts excess power to the immersion heater and we get free hot water from about mid March to mid October, very rarely needing to top up with the oil boiler. We don't have a smart meter so the electricity board pay us the deemed export figure of 50% of generated power. Overall I estimate the system to be worth around £3000 per year now. (3400 x £0.6023 Fit, + 1700 (deemed export) x £.0426 + 1700 x approx 52p (expected cost of units used but not imported from grid, likely to increase) + £amount saved by having free hot water = anybody's guess. So £2047 + £72 + £884 + water heating costs saved. It cost £12,500 to install plus £500 planning permission since the system was installed 'outside the curtilage of the residence'. That figure was worth more then than now of course. Overall though a really good investment, payback in around 9 years and it is a 25 year scheme, tax free.

Overall, the only thing relevant to this discussion is the units generated and location / orientation of the panels. Sorry for the extra drivel.

K

Edit. If electricity goes up to 78p per unit, as one forecast suggests, then 3400 units generated would be worth an estimated 1700 x £.78 = £1360 off your bill plus any export payment from the electricity supplier. With a 4 kW system now costing around £5-£6k, it is payback within around 5 years. Seems like a no-brainer to me.

K

 

[Lard]

Every time I read about existing solar installations it always comes back to virtually the same basic summary…..ie payback in around 10yrs.…..ours exactly the same.

The payback period is also relative in regard to whatever the installation cost was….in other words (and in regard to the FIT scheme) if you paid ‘a lot’ you got a good FIT deal per unit….we paid very little as the FIT scheme was coming to an end and so our low cost reflected in a very small FIT repayment……however, still works out at around 10yr payback.

My point here is that it’s still a good investment because, in theory, the period between payback and so-called ‘failure‘ (ie yrs 10 - 20) is all profit (give or take). Post FIT installations appear to be the same in regard to what the elec companies pay you for excess…..friends of ours with a new system back this up.

As a final note to ponder (and for those in the UK thinking about adding a battery to a FIT related system), please understand that for roughly 50% of the year your system will not generate anywhere near enough to COMPLETELY fill that battery and that will be in the latter, colder months when you’ll need more heating, resulting in more energy being required than produced……ie its not in the summer time when the house doesn’t use anywhere near as much. Ok, the battery will help but, again, please consider that the general payback time for a battery is about 10yrs…..I’ve done the sums for our system and the cost v payback over 10yrs is the same, meaning you get no advantage.….that’s also assuming nowt goes wrong with the battery In that time (look up charging cycles etc)

 

[Terry - Somerset]

With hindsight we should all have fitted PVs 10-15 years ago to enjoy a high feed in tariff. It is worth remembering that the FIT was an inducement to install PVs when the cost of installation was high and the grid price low. Most did not anticipate the high cost of electricity today.

Today - the electricity generated is worth 52p or (possibly) 78p only if it is used to offset usage from the grid. Surplus generated can be exported to the grid at ~5p KWh. More electricity generated can be used but only with a battery installation - which may be worthwhile but adds to the capital cost.

With PVs alone (no battery storage) only 25-50% of energy generated will be used, the surplus exported to the grid for peanuts. Payback will not be 5 years but 10 years+.

A 10 year payback would still seem a good deal as a financial investment. However PVs force other considerations - impact on the value of the house (it may do more in future), and will the owner move before payback is achieved (we don't all stay in one place indefinitely)

 

[Housey210]

what were you looking at, photovoltaic systems and solar? The beeb had an article on a show two weeks ago where the home owner recently installed a system where the surplus power was stored. He bought two or three special batteries and claimed that supplied the electric to feed the house through the night. Costly though.

 

[Mal-110]

Phil
According to the BBC solar installations have gone up to 3000 per month in the UK from around 1000 in July 2020. Discussions over the FIT are not relevant to new installations as we now have the SEG (smart export guarantee) which according to the law must not be zero! Which means energy companies can offer a few pence for good green electricity and then charge 28p for it. Those with FIT payments are quids in at the moment, compared with the SEG. One point about fitting a battery to the system is you must show that you only export green energy from the panels and not stored energy from the battery which they term brown electricity. This seems contrary to the proposed idea of using EV batteries to provide extra to the grid at peak time. You must also get a small generation certificate before you export electricity. From our month of usage the solar panels work well and provide enough energy for all our needs except when cooking around 6pm when the sun moves further west but the battery kicks in and by the following morning we have about 70% left in the battery. This will drop considerably as we go into winter. Considering it heats domestic hot water twice in the day at a 3kw draw it’s not bad at all. As I have mentioned previously it’s grid tied and watching the remote monitor shows the grid chips in now and again with tiny amounts of energy balancing out the charging or discharging process. This amounts to about 1kw a week . Our installer estimated the payback at 12.2 years at current prices. The battery is of course extra. We didn’t really expect a quick payback we wanted a little independence and less reliance on others for fuel.

 

[Spectric]

With this current crisis we might have to forget the green options for now because we must survive right now and then deal with the other issues later so I can see a return to open fires and woodburners.

 

[dickm]

That is a key point. It is the amount of sun that is important, not the temperature. Bear this in mind if you are concerned about winter performance. Our solar thermal system is most productive in February & March. It may be -30C but skies are totally clear and we get lots of heat when we need it most. That may not be the case if your winters are typically overcast.

Sadly, it can be pretty overcast here, EXCEPT when we get a stuck anticyclone when we do reasonably well for PV, but all the turbines are stationary, and the NIMBYs have a field day writing to the P&J to say how useless the turbines are.

 

[Phil Pascoe]

Indeed. I've never been so glad we've a multi fuel stove. I bought 2m³ of both logs and mill offcuts a couple of weeks ago - it was dropped off at 10am and it was the driver's fourth drop of the morning - they're run off their feet. At least unlike most of our neighbours if the electricity goes down we've heat.

After a long discussion with my loved one it looks we may well go for solar thermal - the greatest part of our electricity consumption is water heating.

 

[ian33a]

Brown gold : fallen branches chain sawed and stored yesterday. I just need to split the ones in the foreground and stick them on top. I can't use these immediately in the wood burners but they are a lot drier than I expected.

 

[graduate_owner]

Is anyone thinking to have them fitted or more to the point to fitting their own? The time has come. Our major consumption of electricity is water heating which could well be done by day. Strangely enough bearing in mind a shortage of generating capacity we've just come off economy 7 as a standard tariff is cheaper.

Ours were installed about 13 years ago. Our average annual generation is 3400kW from a 4kW system facing Soith East. We fitted a device which detects when generating surplus, an diverts this to the hot water heater (immersion). We get free hot water roughly from mid March to mid October and supplement things in the winter months with oil. We very rarely use the oil for this in summer, only if there has been a succession of very heavy cloudy days. No idea what we save on oil, but that might give you some idea.

K

 

[Robbo3]

Our 8 panel, south facing, 2kw array, installed in July 2011 has generated just over 21,500 kw to date.
I cleaned them this year due to pigeon poo & algae.