A question about solar panels and battery storage

[Ian]

The DNO are hitting up on requiring the MCS certification and without this you can't register for the export payments.
Also much easier to install a 3.6kW system - no DNO approval required. Above 3.6kW you have to apply to your DNO for permission to connect your system and they can (and have) refused in certain locations.

 

[Tricky Dicky]

Pigeons love to nest under solar panels, whatever you do get netting installed around the panels when they're fitted, otherwise you'll have a whole flock of them up there.

We had panels fitted years ago (no battery) and had an old electric meter (with the spinning disc). When the sun came out it would actually spin the disc the wrong way and reduce our electric reading!!! Took the electricity board a few years before they noticed We've got it set up so that we heat our water with the solar power,something that has reduced our gas bill considerably.

 

[Cantclimbtom]

Not the question you asked, but hope some relevance?
The experience of watching my elderly mum and her panels that she's had some years, is that Solar panel installers aren't necessarily any good at roofing/tiling or (linked to Tricky Dicky post) pigeon defences.
In her case it needed a good roofer to *properly* deal with cracked tiles, loose flashing, leaks, and re-do properly their stupid stuff like anti pigeon spikes stuck to old tiles with silicone (because due to tiles' the gritty surfaces they wash off in a storm) and put proper mesh under the panels. If you can get a decent roofer involved from the start, or know the particular installers collaborate with a decent roofer you might dodge a heap of problems you'll get 2 or 3 years later with poor to mediocre roofing

 

[Mr Mike]

Pigeons love to nest under solar panels, whatever you do get netting installed around the panels when they're fitted, otherwise you'll have a whole flock of them up there.

We had panels fitted years ago (no battery) and had an old electric meter (with the spinning disc). When the sun came out it would actually spin the disc the wrong way and reduce our electric reading!!! Took the electricity board a few years before they noticed We've got it set up so that we heat our water with the solar power,something that has reduced our gas bill considerably.

Yes - people often overlook this. If you still have an old meter HANG ON TO IT fro as long as possilbe. As your getting the same price for export as the cost of your electricity on import.

 

[Pegasus]

We had solar panels + battery installed in Feb - haven't had an electric bill since March and have had refunds throughout summer as we have been generating more than we use. I got a bit addicted to the app showing what we were generating/using - fortunately am (nearly) over that now

We (I) agonised over who to use but were lucky in that we knew someone in the trade who recommended 'Glow Solar' - I would recommend them too - Keir 07454 838837

Things I've learnt:

1. Wish we'd done it sooner.
2. If you have savings, the return from investing them in Solar is way better than the interest you would earn.
3. We were advised to put on as many solar panels as we could, so non sunny side of garage roof has them as well as the sunny side.
4. You may have to be persistent to get the meter to work - Badlad didn't give up until it was sorted.
5. You soon get to learn and understand what is gobbling up the elec in your home! No overfilling the kettle these days....
6. You change how you use electricity - dishwasher used to go on in the evening after tea, now goes on the following morning once we are generating power. Wouldn't dream of using washing machine at night now etc etc. Sun's out - time to wash the bedlinen. Our tariff is most expensive to use between 4pm and 7pm but best to sell then too - so I avoid using elec during these times - often cook say a chilli after lunch then heat up at tea time. I stopped running the tap for hot water and boil the kettle instead - saves on lpg (and water) and uses 'free' elec. I bought a stove top kettle and use it in Winter months to heat up water for my night time cuppa and hot water bottle - it will repay the cost of the kettle in about a decade probably but it makes me smile We've stopped being lazy buggers, bought a decent washing line and dry clothes on that rather than bunging them in the drier. Yup, installing solar has changed how we run the house - it's not the 10p saving you make on doing something, it's more being hyper aware of what you are using, difficult to explain....
7. You replace white goods that break with the best elec efficiency ratings you can. New fridge freezer is AA for example, ditto drier.
8. Our system kicks in if we have a powercut - which we had last week, it's a feature I'd recommend if your power gets cut regularly.
9. We have a Tesla Powerwall - hmmm, ordered before he went mad, have to begrudgingly admit it's brilliant but wish we weren't supporting Musk.
10. Octopus customer service is excellent.
11. Dull rainy days are even crappier now, sunny days even better

If you can afford the initial outlay, do it

 

[Ian P]

Not exactly what you first requested, but does meet your “primary wish”

A 2000 Wh “power station”. This is an “idiot proof plug and play” solution.

They can operate as a “UPS” (uninterrupted power supply), you simply plug the power bank into your home socket and then plug your boiler into the power station. In the event of a power cut the boiler will AUTOMATICALLY be powered by the power station with no human input.

With the boiler just on tick over to prevent frozen pipes, I expect the power station to last a reasonable amount of time.

If it runs out, you can simply take it somewhere with power to charge it up (even to EV charging stations with a readily available adapter).

They are also incredibly versatile if you want to take it somewhere.

We have one of these power stations in the van, Air fryer, microwave, toaster, electric kettle and halogen heater make pre and post caving trips rather luxurious

They retail at £1399 but I am sure a bit of shopping around would get a better deal.

Details

BLUETTI Elite 200 V2 Portable Power Station | 2,073.6Wh 2,600W

Featured with an automotive-grade LFP battery, BLUETTI Elite 200 V2 portable power station with 6,000 plus life cycle, 2,600W output power and 3,900W lifting power, can support daily essentials. Click to explore the best partner for your camping, van life and home backup.

bluettipower.co.uk

 

[Pitlamp]

Hm - I think I'd better ask you for a look at that Ian, next time paths cross! (Not urgent.)

Loved No. 11 Pegasus!

 

[Leclused]

Hi there,

Just some data to think about.

We are a family of 5, living in a rather big old house in the city (house of 1896). We have 9 panels (high perf) and a battery of 10KW. We knew that the setup was not large enough to cover our full usage (6 MWh/year)

There were three reasons why we chose for that setup
1) that was the maximum of number of panels (we could have layed even more high perfo panels but the price was not in balance for those)
2) kids will be leaving the house in the coming years (one just left last week)
3) by this smaller setup the investment was rather slim (8,8k euro net in 2022). Full prices was around 11,5K but goverment gave subsidies for the panels and battery.

Currently we consume most part of our produced energy by ourselves (between 91% and 95%) and that is only feasable with a battery. We only place some energy on the net when we are on holiday. We plan our consumption during the day, avoiding peaks above 3.3KW, because that is the max output of the battery and panels.

Payback time of the setup is between 8 and 9 years. Battery and converter will last around 15 years before replacement. So 7 years of net profit on energy. Which I think is still a good result. However our main reason was not the profit.

Overview of 2025 (so far)

Hope this give you an idea of what is feasable.

 

[Pitlamp]

Superb; thanks!

 

[sn]

We had panels (3.6kw) and 10kwh of batteries ( not Tesla, cheaper ones) installed this year by Octopus, and wish we'd done it earlier. We've been able to drive 2000 miles, power the house and also export what's been falling on our roof..

If we take our (non electric) van away, we can leave the car plugged into the charger to use the surplus solar generation, though it's actually more economical to export all generation the house doesn't use (15p per KWH with Octopus) and charge overnight at 8.5p, thus getting paid to charge the car...

Trouble is, now want an electric van!

 

[ChrisB]

You might be interested to see how the amount generated varies over the year, and between years. Here's a plot of monthly generation over the 14 years our system has been operating. The panels don't seem to have lost much efficiency, although it's worth noting that the technology has improved and new panels could be 50% more efficient.

 

[Hasbeen caver]

Lots of information online and the Everything Electric channel linked in the second reply has some relevant content. However, for concise, clear, informative videos on exactly the questions you are asking, this guy takes some beating:-

Gary Does Solar ☀️

Welcome to my channel, Gary Does Solar. My mission is simple - to provide you with a deeper understanding of solar energy and related technologies, so that you can actively contribute to a sustainable future powered by renewables. My Patreon channel is available here...

www.youtube.com

His introduction videos will answer your basic questions, and he then covers more technical subjects in a really accessible way, if you want to know more.

 

[Graigwen]

My daughter bought a house in Kent with a few solar panels. She did not to knew what to expect.

She told me today that her electricity bill for the past three months was minus £13 odd. She has also had a refund. Obviously this will be different in the winter, but it seems promising.

 

[Pitlamp]

Thanks all - and I'll certainly look at that channel as soon as I get a moment . . .

 

[IanWalker]

@Pitlamp - PM sent

 

[Jenny P]

You might be interested to see how the amount generated varies over the year, and between years. Here's a plot of monthly generation over the 14 years our system has been operating. The panels don't seem to have lost much efficiency, although it's worth noting that the technology has improved and new panels could be 50% more efficient.


View attachment 23642

Pattern similar to mine, 13 panels installed in 2011, so mine have also been working for 14 years. No battery or electric car but do use washing machine and tumbler dryer during daytime and have combination of gas and electric heating. Average income over past 3 years has been £1,500 p.a. with some of this recorded as being exported to grid. (The price per unit produced has gone up over time.) Until recent energy price increases, the income from the panels more than covered the whole energy expenditure (gas & electric) for the house. IMHO all new houses ought to have solar PV installed as standard.
Additional useful point has been 2 solar thermal hot water panels installed in 2006, meaning I can turn off gas-powered boiler from April to September - the roof does it all.
Combine solar thermal and PV and I reckon you've got it made.

 

[MarkS]

Just to add another perspective to this topic (which I've been reading with interest):

I'd crunched the numbers for our house a couple of years ago, hoping that solar would be financially sensible, and didn't get an outcome that looked worthwhile. After a conversation with someone recently who mentioned it being a "no brainer" to get it, and from reading this topic, I looked into it again. I even got a design & quote from Octopus, and it still didn't really make sense financially. We're a fairly low-use household without a large south facing roof, and it looks like we'd have roughly a 15 year payback period (and this is a misnomer, since it assumes that all you can do with the capital is match inflation). I absolutely appreciate that there is good justification for solar aside from the financial aspect, but from a purely economic perspective it's certainly not worth it for everyone.

 

[cavemanmike]

It’s less attractive nowadays than it was originally. I’ve had 4kw panels for 10 years and it was a no brainier then, i also put a smart plug on the hot water tank . Works a treat

 

[hannahb]

Just to add another perspective to this topic (which I've been reading with interest):

I'd crunched the numbers for our house a couple of years ago, hoping that solar would be financially sensible, and didn't get an outcome that looked worthwhile. After a conversation with someone recently who mentioned it being a "no brainer" to get it, and from reading this topic, I looked into it again. I even got a design & quote from Octopus, and it still didn't really make sense financially. We're a fairly low-use household without a large south facing roof, and it looks like we'd have roughly a 15 year payback period (and this is a misnomer, since it assumes that all you can do with the capital is match inflation). I absolutely appreciate that there is good justification for solar aside from the financial aspect, but from a purely economic perspective it's certainly not worth it for everyone.

Likewise. I was really disappointed when a solar company basically told us not to do it, even knowing we were getting an electric vehicle.

 

[Leclused]

Just to add another perspective to this topic (which I've been reading with interest):

I'd crunched the numbers for our house a couple of years ago, hoping that solar would be financially sensible, and didn't get an outcome that looked worthwhile. After a conversation with someone recently who mentioned it being a "no brainer" to get it, and from reading this topic, I looked into it again. I even got a design & quote from Octopus, and it still didn't really make sense financially. We're a fairly low-use household without a large south facing roof, and it looks like we'd have roughly a 15 year payback period (and this is a misnomer, since it assumes that all you can do with the capital is match inflation). I absolutely appreciate that there is good justification for solar aside from the financial aspect, but from a purely economic perspective it's certainly not worth it for everyone.

You have to do the math for your situation.
- total cost
- orientation
- subsidies
- future of the household ( kids leaving the house)
- battery (or not?) for me this was a no brainer. Without a battery it was not worthwhile.
- sometimes it’s better to put a smaller (cheaper) installation that will not cover your full usage
-…