Solar panels still worth it?

[Stevewoody]

We are considering having a solar & battery setup but unsure of what a realistic payback period is. If it takes (say) 10 years to break even and the kit has a lifespan of 10 years or so is it not the case that one would never be in credit due to the cost of replacing everything?

Also, I heard that with a full solar & battery system, standing charges by energy company to whom electricity is exported to, no longer apply. Is this true?

 

[Jacob]

Solar PLUS heat pump seems best option. Expensive, no short term payback until prices go much higher, but probably adds a lot of value to your house as they are still going up well ahead of inflation and interest rates.
It's a gamble, but also a commitment to a greener future.
Quite how it might work out for the whole population is another issue - it seems that half or more of the population could not afford it and state will have to fund it in the future. Sooner the better.

 

[Nail]

Solar PLUS heat pump seems best option. Expensive, no short term payback until prices go much higher, but probably adds a lot of value to your house as they are still going up well ahead of inflation and interest rates.
It's a gamble, but also a commitment to a greener future.

You need the heat pump the most in the winter when you get the lowest production of solar PV....

 

[Sideways]

NW UK
9kW of top tier panels and enough battery to run for 2 days+ on a full charge.
These are the graphs for the last 2 years.
Self sufficient and more for 8 months with hot water to spare and some export income.
The four winter months we're totally dependent on the gas CH and hot water.
I expect to break even with this but it was pricey and I expect it'll take more than a decade.

 

[Eshmiel]

You need the heat pump the most in the winter when you get the lowest production of solar PV....

It's still getting a 3.5:1 or 4:1 energy out/in return rate, though, whatever the source of the lecky.

 

[Sideways]

That COP just makes electric heat pump near even with a gas boiler.
There's no extra saving to pay off the massive capital cost of the heat pump and upgrades to make low temperature heating viable in an old house.

 

[Nail]

It's still getting a 3.5:1 or 4:1 energy out/in return rate, though, whatever the source of the lecky.

That’s fine but it doesn’t change what I mentioned. Some people think they could install both systems and run it off grid but it’s not realistic all year.

 

[Eshmiel]

That COP just makes electric heat pump near even with a gas boiler.
There's no extra saving to pay off the massive capital cost of the heat pump and upgrades to make low temperature heating viable in an old house.

It depends on what sort of heat pump you install and how its used.

The least expensive heat pump is an air-source generating warm air into the house but not heating any water for bath or radiators. They're quick and easy to install and can act as air coolers/conditioners as well as air heaters.

If hot water is also wanted, that means a larger heat pump, more piping, maybe a new tank. If hot water for radiators is needed that's more pipework and probably new radiators designed for 50 degree water rather than 70 degree water.

If a ground source hear pump is wanted instead of an air source heat pump, it'll be tens of thousands to drill a vertical hole or numerous thousands to dig a long one metre deep hole.

But the first option costs half of what a gas boiler would cost. A gas boiler isn't green and can't do air cooling/conditioning. In fact, it pollutes.

 

[HamsterJam]

We inherited a 13x300w (=3.9kW) Solar Edge installation when we bought our current home.
It was installed in 2015 and cost £6k. It is approaching 10years old and attracts a lower rate FIT meaning we get just under 10p for every kWh we generate, whether we use it or not.
The panels are divided across 3 aspects, 5x South, 5x East and 3x West and have optimisers.
From this installation, we get about £300/yr in FIT payments plus in summer, we heat most of our hot water for free.

Unfortunately, we are carrying a fault on the system which I discovered shortly after we bought the house - one optimiser on the West elevation has stopped reporting data to the inverter and I believe the associated panel may not be generating.
Although the panels and optimisers have a 25year manufacturer warranty, we are unable to access it as the installer ceased trading in 2017, the manufacturer will only deal with its affiliated installers and alternative installers we have approached aren’t interested in repairs, only replacing the entire system.

So it rather looks like any repair will have to be DIY using secondhand parts.

 

[Sideways]

@HamsterJam
That's really annoying and I hope anyone considering Solar Edge treat it as a big "stay away".
While this supplier messed me about twice and I don't like them, I notice you can buy Solar Edge optimisers from Midsummer, here :
https://midsummerwholesale.co.uk/buy/SolarEdge/S440
£70 for the part, it may be worth just buying new if this is compatible with you installation.
If it's the panel, then sourcing older types to ensure a cosmetic match does tend to be pricey.

 

[Jacob]

Toying with the idea of solar plus air heat pump and would need new CH rads etc. so it's interesting reading this thread.
It's put me right off! I don't think I'll bother.
Huge amount of money, not a lot of pay back if any, expensive maintenance with risk of major breakdown. But most of all it all depends on reliable infrastructure of electricity supply and affordable back up services.
Am going to get the roof replaced and spend a lot on insulation and other heat conserving measures. Also add greenhouse/conservatory to the house which will give us massive solar gain. Glad I put in a woodburner.
Maybe in a few years time we'll have clearer idea of what the climate change will bring, and whether or not we have intelligent governmental policies, which surely will have to include massive financial support for green energy developments, at every level from massive infrastructure down to individual buildings.
I think there is a huge bias towards expensive techno solutions to the CC prob, in spite of technology being the cause in the first place. Most evidenced in the excitement over EVs and personal transport. Maybe more "passive" solutions are the way; changing the way we live and a reduction in dependency on high tech.
PS Think of a small town say 2000 dwellings and other premises.
Surely it would make much more sense to:
have them all insulated plus low tech solar gain etc etc all with near zero running costs and a level of "resilience"
add public transport for all
add large wind/solar/hydro farm for all
Rather than having 2000 micro systems, on 2000 roofs, with 2000 heat pumps, and 2000 EVs charging at 2000 power points, all of which are highly obsolescent and not future proof.

 

[Cooper]

I have one observation, there is much discussion about pay back. Perhaps someone could explain what the payback is for a replacement boiler? If solar panels reduce expenditure on electricity and a new boiler reduces gas consumption

 

[Phil Pascoe]

Surely it would make much more sense to have them all insulated ...

I would think most buildings that can be adequately insulated already are. Roof insulation was ridiculously cheap when subsidised 15 years or so ago, and many places were done free quite recently with grants. The problem is that many buildings are either impossible or prohibitively expensive to insulate properly.

Large wind and solar farms are no earthly use in the depths of cold, still, overcast winters and of course still need back up power stations.

A neighbour has an ASHP - in a cold month his electricity bill is about the same as I pay for a winter's logs - £440. (Don't shoot the messenger, I don't know the details of his electricity supply.)

I'm still thinking about panels (my wife is anti) because our largest consumer of electricity is water heating (which of course can be done at any time), and besides that I'm home all day so can use white goods etc. at the most opportune times.

 

[John Brown]

Toying with the idea of solar plus air heat pump and would need new CH rads etc. so it's interesting reading this thread.
It's put me right off! I don't think I'll bother.
Huge amount of money, not a lot of pay back if any, expensive maintenance with risk of major breakdown. But most of all it all depends on reliable infrastructure of electricity supply and affordable back up services.
Am going to get the roof replaced and spend a lot on insulation and other heat conserving measures. Also add greenhouse/conservatory to the house which will give us massive solar gain. Glad I put in a woodburner.
Maybe in a few years time we'll have clearer idea of what the climate change will bring, and whether or not we have intelligent governmental policies, which surely will have to include massive financial support for green energy developments, at every level from massive infrastructure down to individual buildings.
I think there is a huge bias towards expensive techno solutions to the CC prob, in spite of technology being the cause in the first place. Most evidenced in the excitement over EVs and personal transport. Maybe more "passive" solutions are the way; changing the way we live and a reduction in dependency on high tech.
PS Think of a small town say 2000 dwellings and other premises.
Surely it would make much more sense to:
have them all insulated plus low tech solar gain etc etc all with near zero running costs and a level of "resilience"
add public transport for all
add large wind/solar/hydro farm for all
Rather than having 2000 micro systems, on 2000 roofs, with 2000 heat pumps, and 2000 EVs charging at 2000 power points, all of which are highly obsolescent and not future proof.

I agree with a lot of this. New builds should be insulated to the maximum, and built to passive solar designs. It's been talked about for decades, but I believe the building lobbies are too powerful. It's way more expensive, and difficult, to retrofit.

Ground source heat pump loops would also be cheaper and easier to install at build time.

Would it be possible to use some of the waste heat from data centres/crypto mining/high frequency trading?
We've become accustomed to cheap energy and using it wastefully.

 

[Phil Pascoe]

My friend installed his own solar thermal system in 1982 - we said then that all new builds should have solar panels and grey water systems.

I'm unsure about ground source around here - if you put a bean pole in the ground you might open up a shaft.

 

[Jacob]

Hiya
I run my workshop off solar energy. I bought my panels off amazom along w8th the batts and inverter
I charge my cordless tools run the lighting, and most of my corded tools
Even my wood lathe and dust extraction unit
So yes for me at least it’s worth it as I am off grid, and it’s back up power for my medi equipment

Does this mean that if I have solar panels it would be practical to use the electricity from them even if I am disconnected from the grid? How practical, maybe just intermittent, via batteries etc?
I'm interested in the "resilience".

 

[Sideways]

@Jacob
There's a thing now called 'in roof" solar panels.
Basically, the solar panels are fitted flush with a waterproof tray behind. Where they are, they replace the tiles. It makes for a very neat job and seems to be the preferred, even standard, way to do solar on new builds.
If you are having the tiles replaced this might be a more cost effective option for you.
A solar diverter to dump excess power into your immersion heater can soak up a useful amount of surplus power, that 15p per kWh export deal is another. So there maybe value in solar without the high cost of heat pumps.
It isn't hard to adapt our routines in retirement to do laundry or bake bread when the sun is shining.

 

[Nail]

Interestingly a friend who had solar installed a year or two ago regrets buying the immersion diverter. He doesn’t feel it was worth the cost.

 

[Nail]

We inherited a 13x300w (=3.9kW) Solar Edge installation when we bought our current home.
It was installed in 2015 and cost £6k. It is approaching 10years old and attracts a lower rate FIT meaning we get just under 10p for every kWh we generate, whether we use it or not.
The panels are divided across 3 aspects, 5x South, 5x East and 3x West and have optimisers.
From this installation, we get about £300/yr in FIT payments plus in summer, we heat most of our hot water for free.

Unfortunately, we are carrying a fault on the system which I discovered shortly after we bought the house - one optimiser on the West elevation has stopped reporting data to the inverter and I believe the associated panel may not be generating.
Although the panels and optimisers have a 25year manufacturer warranty, we are unable to access it as the installer ceased trading in 2017, the manufacturer will only deal with its affiliated installers and alternative installers we have approached aren’t interested in repairs, only replacing the entire system.

So it rather looks like any repair will have to be DIY using secondhand parts.

If you’re on Facebook there’s quite an active diy solar group that can probably give some good advice as to what to do.

 

[Phil Pascoe]

Whether you have mains gas probably has a large bearing on how worthwhile solar panels etc. are.