The plummeting cost of solar.

[DrFfybes]

I wasn't sure where to post this, but thought this board was as good as anywhere.

Last July we had solar panels and battery fitted. We had some on the garage, knowing we would get more on the South aspect of the house once it was reroofed. We also had a 5kWh battery.

At the time the panels were about £180 each, with the battery and controller coming in at just under £5k.

This weekend the installer came to check the scaffold and roof, and has quoted for another 8 panels and additional 5kWh battery.

The Battery management system is still slightly cheaper, now circa £8-900, but the battery packs themselves were £3500 when we were quoted last May, and the quote this time is £2100 installed.

For the 8 panels the quote is £2350, of which only about £700 is the panels as they half the price of a year ago. We therefore thought this quote was a bit of a liberty, so looked at the rest of the list he sent. It turns out the optimisers are now 50% of the cost of a panel, and the mounting bracketry (mounting rails, anchors, fixings, and panel clamps) were more expensive than the panels themselves, then there are some caling and connectors on top (prices from Midsummer wholesales). Suddenly the £500 ish for 2 people for the day didn't seem entirely unreasonable.

That is a rather astounding drop in price in under a year. I suspect Jeremy Hunt will be seeing if he can sneak them in the 'shopping basket' used to measure inflation before the budget

Paul

ps - yesterday our East-West array generated more than it did in the whole of December and we exported more than Nov, Dec, and Jan combined.

[spiderbill]

I wasn't sure where to post this, but thought this board was as good as anywhere.

Very interesting, thanks. I've been considering panels and will starting looking at the prices here in Slovenia to see if they are dropping at a similar rate. A couple of neighbours have had them installed in the last couple of years and say that they use far less wood in their furnaces since then. Since I'm now almost 69 and don't want to still be chopping wood daily in the winter in 10 years time this would be worth it even if it doesn't prove to be financially profitable in that time period. Though I'll be asking them about how they got on over the recent two weeks of heavy rain when I presume they didn't generate anything much.

They do seem to still get surprisingly decent performance over the winter in general so it could be useful to run alongside my heat pump on the water tank which handles the water for about 8 months of the year. I had a combination wood and oil furnace installed about 7 years ago to replace the ancient wood-only one, but the oil burner is currenty out of action so adding wood is an hourly task in the evening. Maybe add an air source pump that doubles as summer air-con to keep some background heat going for the worst of the winter.

thanks again
Spiderbill

[the0ni0nking]

Indeed, and this certainly piqued my interest.

The purely self-interested issue for me is that while I could afford the capital outlay to install them on my PPR, I'm not likely to be living in that property long enough to get remotely close to recouping the benefit.

I also own a share of a block of 4 flats and the roof on that property is in the process of failing - I do wonder whether it would be beneficial to - at the same time as getting scaffolding up to replace the roof (say a c£15k expense all in) also try and install solar panels. But again, I'm not sure that makes financial sense either as all that benefits is the leaseholders who will pay less for their electric - unless there is a means for the owners of the freehold to separately extract the value of the electricity produced. However, that would then start up another HMRC debate over what the freehold company is doing now trading energy as opposed to just owning the freehold and earning two fifths of naff all ground rent.

[DrFfybes]

The purely self-interested issue for me is that while I could afford the capital outlay to install them on my PPR, I'm not likely to be living in that property long enough to get remotely close to recouping the benefit.

I also own a share of a block of 4 flats and the roof on that property is in the process of failing - I do wonder whether it would be beneficial to - at the same time as getting scaffolding up to replace the roof (say a c£15k expense all in) also try and install solar panels. But again, I'm not sure that makes financial sense either as all that benefits is the leaseholders who will pay less for their electric - unless there is a means for the owners of the freehold to separately extract the value of the electricity produced. However, that would then start up another HMRC debate over what the freehold company is doing now trading energy as opposed to just owning the freehold and earning two fifths of naff all ground rent.

Firstly, the panels may well increase the property value - they would certainly affect the EPC rating.

With the flats, if the freeholder pays to light the common areas then presumably you have a seperate meter so connecting Solar on Export would be straightforwards. However if it has a flat roof then the panel mounts are quite expensive.

[csearle]

With the flats, if the freeholder pays to light the common areas then presumably you have a seperate meter so connecting Solar on Export would be straightforwards.

Place I was at last week had the communal loads distributed amongst the various flats. Path-of-least-resistance approach to it all. C.

[the0ni0nking]

Yes, the communal areas are separately metered so it could certainly work. Although, I suspect getting the fellow freeholders to agree to fund such a thing would be unlikely.

I've never done the maths, but all the posts I've seen and reading I've done suggests the payback isn't really great - and would likely be worse in a scenario where the electric that would be exported would not be at specific times (it would likely be whenever it is light) as there is no usage other than a few communal lights.

If I lived in the block then I'd likely be able to manipulate things accordingly but the majority of the flats are rented out rather than having an interested owner occupier.

[Hallucigenia]

That is a rather astounding drop in price in under a year.

Some of that is the comparator - solar installers were insanely busy after energy prices spiked, Covid disrupted everything, shipping prices spiked etc etc. Whereas now things are calming down again.

all the posts I've seen and reading I've done suggests the payback isn't really great... the majority of the flats are rented out rather than having an interested owner occupier.

On the other hand, if you're getting work done on the roof, it may be the cheapest option long-term, if you extrapolate the trend in energy efficiency for rental properties. Commercial rentals will have to be EPC C from 2025/28, one rather suspects that domestic rentals will have a similar requirement imposed in the not-distant future. Certainly a prudent managing committee would be thinking what might need to be done in such an eventuality.

[DrFfybes]

Yes, the communal areas are separately metered so it could certainly work. Although, I suspect getting the fellow freeholders to agree to fund such a thing would be unlikely.

Ahh - this is a communally owned Freehold?

As I said above - depends on the roof type, if Flat then don't bother. Also you'll be on a commercial supply so I don't know what tarrifs are available.

Commercial rentals will have to be EPC C from 2025/28, one rather suspects that domestic rentals will have a similar requirement imposed in the not-distant future. Certainly a prudent managing committee would be thinking what might need to be done in such an eventuality.

It depends ho they can arrange it - I expect the leaseholders will have resposibility for communal costs but the install would not affect the EPC. However it would provide an ongoing income stream for the Management Fund and reduce maintenance bills.

[the0ni0nking]

It depends ho they can arrange it - I expect the leaseholders will have resposibility for communal costs but the install would not affect the EPC. However it would provide an ongoing income stream for the Management Fund and reduce maintenance bills.

That was my thought last night - if it's flowing through the commercial communal meter then I wouldn't see how that would impact the EPC for the individual flats.

On the EPC front, I've never really paid much attention to them.

I've pulled out the paperwork for one of the flats and it's rating is D (57) with a potential rating of D (58). I'm not sure I follow the logic on the EPC but the recommendation to upgrade the ranking by 1 is "low energy lighting for all fixed outlets". This has now been done in any case

It then goes onto "further measures to achieve even higher standards - replace single glazed windows with low E double glazing. This has also been done as when one of the units started to fail I replaced them all. Due to the nature of the building this needed planning permission and wasn't cheap (as they were all substantial Georgian style arched windows - the planning officer wanted aluminium frames which would have been double the cost again but was over-ruled by the decision maker). This apparently would lift the rating to D61.

The last element is 50mm internal or external wall insulation which would lift the rating to C75 - but these are solid walls built in the 1800s so suspect while they can be insulated the cost will be astronomical compared to standard cavity insulation. Unless there's grants available to support that, I suspect I'd be more likely simply to dispose of the property if at some point the EPC rating had to be at C to allow residential letting. So a win, should it come to pass, for removing one more property from the rental market unless someone takes on the work to do it.

[funduffer]

I purchased my solar panels in December 2020 - 13 panels 4.225kW system. It cost just over £4k all in. No battery yet!

I am on track to pay back in year 7 or 8.

If returns continue as they are now I will have an IRR of 13% after 20 years. I am happy with this.

The key to good returns is to use the solar when it is available in peak tariff hours, and also get a good export tariff (SEG). In the summer you generate so much power you will export a huge amount, so you need to cash in.

I have a SEG with Scottish Power who pay 12p per kWh exported.

My electricity supplier is Octopus, where I have the Intelligent Octopus Go tariff. This is 29p per kWH during peak hours and 7.5p off-peak. As I have an EV, it pays me to charge it at night and export most of my solar during the day. Currently only a third of my electricity usage is during peak hours.

If you get the tariffs right, solar is a great investment currently.

FD

[BullDog]

I purchased my solar panels in December 2020 - 13 panels 4.225kW system. It cost just over £4k all in. No battery yet!

I am on track to pay back in year 7 or 8.

If returns continue as they are now I will have an IRR of 13% after 20 years. I am happy with this.

The key to good returns is to use the solar when it is available in peak tariff hours, and also get a good export tariff (SEG). In the summer you generate so much power you will export a huge amount, so you need to cash in.

I have a SEG with Scottish Power who pay 12p per kWh exported.

My electricity supplier is Octopus, where I have the Intelligent Octopus Go tariff. This is 29p per kWH during peak hours and 7.5p off-peak. As I have an EV, it pays me to charge it at night and export most of my solar during the day. Currently only a third of my electricity usage is during peak hours.

If you get the tariffs right, solar is a great investment currently.

FD

Interesting. Will you be able to charge a battery pack at 7.5p per unit and sell it the next day for 12p?

[servodude]

I purchased my solar panels in December 2020 - 13 panels 4.225kW system. It cost just over £4k all in. No battery yet!

I am on track to pay back in year 7 or 8.

If returns continue as they are now I will have an IRR of 13% after 20 years. I am happy with this.

The key to good returns is to use the solar when it is available in peak tariff hours, and also get a good export tariff (SEG). In the summer you generate so much power you will export a huge amount, so you need to cash in.

I have a SEG with Scottish Power who pay 12p per kWh exported.

My electricity supplier is Octopus, where I have the Intelligent Octopus Go tariff. This is 29p per kWH during peak hours and 7.5p off-peak. As I have an EV, it pays me to charge it at night and export most of my solar during the day. Currently only a third of my electricity usage is during peak hours.

If you get the tariffs right, solar is a great investment currently.

FD

Interesting. Will you be able to charge a battery pack at 7.5p per unit and sell it the next day for 12p?

One would, but there are caveats
here's a video on the ROI of a home solar battery installation https://youtu.be/DCAMDeA00vM?feature=shared
the arbitrage you're talking about is handled in the "Get Rich Quick Scheme" section and looks less attractive if you consider the cost of the battery (but you could also consider that a sunk cost at this point)

Where this will become a bigger thing will be with more dynamic tarrifs (e.g. ones that track the market rate) where a forced export might be able to net a decent return in a short time - such as during periods of extreme grid stress or problems

[DrFfybes]

I purchased my solar panels in December 2020 - 13 panels 4.225kW system. It cost just over £4k all in. No battery yet!

FD

Interesting. Will you be able to charge a battery pack at 7.5p per unit and sell it the next day for 12p?

For FD - speaking more to the installer, the kit went up masivley during Covid and when the energy prices went up. Whilst he is still just as busy as last year, we're actually seeing prices returning more to pre-covid levels. It looks like you would have just got yours in before the price rises.

To Bulldog - yes you can charge on a cheap tariff and export, but better is to charge at a cheap rate (I charge our batteries overnight at 25p) and then just use it during the day when it is 30p, or wait until they have a "Saver Session" where you can export at £1.90 or so

Battery payback at last year's prices was "pretty much never" at £5k for 5kWh, and our battery has apparently discharged 1512 kWh since installation at the end of July. If we assume charged at 15p (overnight rate or export rate) and used at 27p then that is £180 in 7 months, so £300/year. This return will increase now I can export to saver sessions, perhaps by a couple of quid a month depending on how often they are, so return is about 7%, probably better investing in a tracker However the second battery at £2100 is a much better bet, the return will be slightly less as it won't cycle as much as the first battery which was usually depleted by midnight, but it will mean I can draw 5kW compared to 2.5 so whereas now the oven take grid energy that will all come from battery.

Paul

[BullDog]

Interesting. Will you be able to charge a battery pack at 7.5p per unit and sell it the next day for 12p?

For FD - speaking more to the installer, the kit went up masivley during Covid and when the energy prices went up. Whilst he is still just as busy as last year, we're actually seeing prices returning more to pre-covid levels. It looks like you would have just got yours in before the price rises.

To Bulldog - yes you can charge on a cheap tariff and export, but better is to charge at a cheap rate (I charge our batteries overnight at 25p) and then just use it during the day when it is 30p, or wait until they have a "Saver Session" where you can export at £1.90 or so

Battery payback at last year's prices was "pretty much never" at £5k for 5kWh, and our battery has apparently discharged 1512 kWh since installation at the end of July. If we assume charged at 15p (overnight rate or export rate) and used at 27p then that is £180 in 7 months, so £300/year. This return will increase now I can export to saver sessions, perhaps by a couple of quid a month depending on how often they are, so return is about 7%, probably better investing in a tracker However the second battery at £2100 is a much better bet, the return will be slightly less as it won't cycle as much as the first battery which was usually depleted by midnight, but it will mean I can draw 5kW compared to 2.5 so whereas now the oven take grid energy that will all come from battery.

Paul

Thanks. £2100 for a 5kw battery? That's getting sensible. I don't really have a suitable site for PV solar. But I can charge a battery at 7p a unit. That's getting interesting as my day time use at 29p per unit is about 45% of my electricity consumption. Peak time export capability would be a cherry on the cake.

[DrFfybes]

Thanks. £2100 for a 5kw battery? That's getting sensible. I don't really have a suitable site for PV solar. But I can charge a battery at 7p a unit. That's getting interesting as my day time use at 29p per unit is about 45% of my electricity consumption. Peak time export capability would be a cherry on the cake.

That's a second Huawei battery to add to my existing modular system - I've already got all the control electronics so these would need to be factored in.

There is cheaper stuff out there, and some brands (Givenergy mainly) are compatible with Octopus' smart agile intelligent flexi tariff (or whatever the exact name is) which will automatically charge it for you at free/cheap periods and discharge when demand is high. Octopus website says which are compatable systems. One tariff even allows you to use your electric car as a domestic battery to charge/discharge as they deem appropriate. I assume you can set a minimum charge threshold for the to do this otherwise you could be caught short

Paul

[BullDog]

Thanks. £2100 for a 5kw battery? That's getting sensible. I don't really have a suitable site for PV solar. But I can charge a battery at 7p a unit. That's getting interesting as my day time use at 29p per unit is about 45% of my electricity consumption. Peak time export capability would be a cherry on the cake.

That's a second Huawei battery to add to my existing modular system - I've already got all the control electronics so these would need to be factored in.

There is cheaper stuff out there, and some brands (Givenergy mainly) are compatible with Octopus' smart agile intelligent flexi tariff (or whatever the exact name is) which will automatically charge it for you at free/cheap periods and discharge when demand is high. Octopus website says which are compatable systems. One tariff even allows you to use your electric car as a domestic battery to charge/discharge as they deem appropriate. I assume you can set a minimum charge threshold for the to do this otherwise you could be caught short

Paul

That's useful to know. I will check up on the Octopus tariff. At the moment I'm on the 11.30pm to 5.30am tariff with intelligent charging on a Ohme charge point.

[funduffer]

I purchased my solar panels in December 2020 - 13 panels 4.225kW system. It cost just over £4k all in. No battery yet!

I am on track to pay back in year 7 or 8.

If returns continue as they are now I will have an IRR of 13% after 20 years. I am happy with this.

The key to good returns is to use the solar when it is available in peak tariff hours, and also get a good export tariff (SEG). In the summer you generate so much power you will export a huge amount, so you need to cash in.

I have a SEG with Scottish Power who pay 12p per kWh exported.

My electricity supplier is Octopus, where I have the Intelligent Octopus Go tariff. This is 29p per kWH during peak hours and 7.5p off-peak. As I have an EV, it pays me to charge it at night and export most of my solar during the day. Currently only a third of my electricity usage is during peak hours.

If you get the tariffs right, solar is a great investment currently.

FD

Interesting. Will you be able to charge a battery pack at 7.5p per unit and sell it the next day for 12p?

Unfortunately my current SEG account states that exported electricity has to come from a renewable source. So charging a battery overnight from the grid, and exporting it the next day is probably not in line with their T&C’s. There may be other SEG accounts that allow this, and I agree it would hugely improve the economics of buying a battery. In the summer my solar panels can generate over 20kWh in a day. I use only about 5 kWh a day in the home, so it would be of great benefit to be able to export this surplus and be paid for it.

FD

[yieldhog]

I keep reading about the plumeting cost of solar installations and was pleasently surprised when I recently got my first quote. I then obtained further quotes and list them all below:

1 18 Panel 10 Kw Give Energy £17,735
2. 12 Panel 4.74 Kw Give Energy £8,823
3. 20 Panel 7.6 Kw Give Energy £15,519

These are all for our modern two story detached house.

Are these about right and what factors should I be looking for when I choose the installer?

Thanks,

Y

[DrFfybes]

1 18 Panel 10 Kw Give Energy £17,735
2. 12 Panel 4.74 Kw Give Energy £8,823
3. 20 Panel 7.6 Kw Give Energy £15,519

Presumably this includes Scaffolding, which can be quite expensive per roof aspect. Are they all quoting the same panel make, and have you got a location organised for the battery and kit? The batteries are not silent in our garage, there is a very quiet fan in there somewhere I think and occasionally there is a feint high pitched whine.

Did one installer say why they are only using 12 panels and another 20? A stab in the dark is it is down to orientation and one installer decided one side (or 2) was not worth it?

Does the smaller install have capacity to add more panels? - does the inverter have spare capacity?

South and West facing work better - we have 13 panels on the garage, 10 facing East and 3 West. Total output per panel since August install is 78kWh from East facing 118kWh from the West ones although the West ones have a completely clear view and the East ones have a bit of tree shade early on. Optimisers help with this. All 13 panels are on one input on our inverter, leaving the other input for the South facing panels just ordered for when the builders finish reroofing.

Are the batteries modular - ie is it easy to add another later if you want? Do you have or are planning on an electric car? - If so then the domestic battery will be a minor consideration if you have a big one parked outside with bidirectional capabilty.

What is your daily consumption? - it isn't really worth having more battery then you use in a day as you can charge from cheap overnight power in Winter. The max power you can draw from the battery/ies usually increases with the capacity so the 10kWh battery will usually provide 5kW max current which should do nearly everything, the small battery would need topping from solar or the grid if you boil a kettle.

Givenergy batteries are about £2.5k for 5kWh so perhaps add another battery to option 2?

Otherwise it looks pretty good, For us now it is circa it £2k for Inverter and battery control, £2500/kWh battery capacity, and about £300/panel. Plus Scaffolding.

Paul

[yieldhog]

Thanks for your post Paul. I'll try to answer all your questions.

All the quotes include scaffolding.
The smaller number of panels would fit on an east facing roof and the 20 panels would be on two parts of the roof, east and SW.
The battey(s) would go in the integral garage.
We do not have an electric car and are unlikely to get one.
Our current electric consumption is a bit irrelevent at this point since we are in the process of going all-electric and eliminating gas completely. Hence we want to install as much capacity as possible. However, there may be a case for installing a system that allows for more batteries at a later date since they may get cheaper and more efficient.
We are with Octopus energy which uses 100% green energy.