Subscription solar panels

tfhnota

Ideally, with an air-to-air you want to arrange the house so that the lounge is heated and the other rooms get a flow of that heat when their doors are open, rather than go to the expense of having an indoor unit in every room, combined with decent insulation and possibly removal of a lot of non-south-facing windows or at least extra layers of glazing (more cost effective than extra heating) but that probably means knocking some internal walls to achieve and won't work with large families who each like their own separate space.

Newbie_John

Totally agree, very similar to our set up. One unit, open doors, constant heating downstairs to around 21°C enough to keep bedrooms upstairs at about 19°C. 40m^2 per floor. SE England.

Average usage per day over last few months, mixing Agile and cosy with average about 20p/kWh:

Decmeber 6kWh (£36 for a month)

January 10kWh (£60 for a month)

February 7kWh (£42 for a month)

March 4kWh (£24 estimated)

QrizB

Solar? £6k+

£3k for a usefully large system. I paid that in 2022 and prices have fallen since.

Battery? £6k+

Again, under £3k for one that will suit many households.

OP hasn't shared any quote details, either here or on Green & Ethical, so we don't know what size/cost system they're thinking of.

Newbie_John

As we're on MSE I will stick to their averaging of £6100 per solar:

https://www.moneysavingexpert.com/utilities/solar-panels/

Same with battery, sure you can get the cheaper ones for self installation but.. most people will still end up with Tesla Power wall PowerWall for more than £6k.

or even OP asked for SunSave subscription.. which costs £16k for battery and solar (including their interest rates).

QrizB

As we're on MSE I will stick to their averaging of £6100 per solar

Nobody over on Green and Ethical thinks that number makes any sense, though. It's ridiculed whenever it's mentioned.

Here's an installation from last year where they got 5.5kWp of PV plus a 9.5kWh battery for "less than £7k" total:

https://forums.moneysavingexpert.com/discussion/comment/81588353#Comment_81588353

or even OP asked for SunSave subscription.. which costs £16k for battery and solar (including their interest rates).

We can hopefully both agree that £16k is a terrible deal!

Newbie_John

This looks like possibly the cheapest case there not self installed. All relies on GivEnergy which are in financial troubles meaning their warranty is useless. Very risky thing.

Checking other topics and you can see £10k+ quotes with Tesla PowerWall.

Anyway, were drifting away from the topic - SunSave is bad offer.

sheenas

https://forums.moneysavingexpert.com/discussion/comment/81928061#Comment_81928061

You could spend £2K to heat a single room with an Air2Air solution while for 2K you get a gas boiler to heat the whole house. A proper heat pump would cost less after the grant, but may need other changes and typical these are 2K upward.

The key element is running costs. typically heat pumps use 3,000–7,000 kWh of electricity annually and no solar means that going to be expensive on a stand electricity bill. Consider solar depending on sunlight, orientation, and location. A standard 4kW system (10–12 panels) generally produces around 3,400–4,200 kWh per year, covering a large portion of a household’s energy needs. You could choose to save energy using a battery or export back to the grid. Either way 7,000-4200kwh leaves 2800kwh to pay for i.e. £775.

That leave the pay times on the investment to consider and that rather more complex, but typically solar is 7 years and heat pumps at lot longer. Using the above logic you can see why solar/battery is worth getting before a heat pump. You could further consider

tfhnota

Just been lookin at AlphaESS batteries, seem reasonably priced and I think use EVE cells which are well regarded but you are supposed to pair it with an Aplha inverter - the batteries are about twice the price of buying a simple 48v battery from the depths of amazon or ebay. Energy companies are likely to offer less attractive solar and cheap rates going forward, the government likely to squeeze them to keep the cost of living down, so payback times are going to be theoretical, to say the least. But having some resilience against grid breakdowns is a good idea.

Newbie_John

@sheenas , very theoretical examples you bring.

We've installed an A2A on 1st Nov 2025, single unit downstairs as it's all open plan (40m2) and that keeps 21°C and also makes 19°C upstairs - which works well. There's no need for more units in our case.

Usage: 129kWh Nov, 188 Dec, 271 Jan, 195 Feb, 87 so far in March - total 555kWh over winter. So under 1000kWh per year.

Regarding your solar calculations, most of it will be produced in summer when there is no need for it so yes, you can choose to sell for 12p/kWh - recently cut from 15p, so in the next 10 years when people get more and more solar likely more cuts ahead. Let's say you exported all 4000 at 12p so you'll get £480 - but look at it differently - you put £7500 (cost of solar and battery) to saving account of 4% and you get £300 a year.

There's a lot of ToU tarriffs out there and I'm on fixed Cosy with 13.5p rates dropping to 10p in April and with COP of 4 for A2A it costs me half the price of gas to heat during these periods.

Solar & battery costs from £7500, and let's say payback is 7-10 years - you don't really save anything during that period - you're paying off investment, after 7-10 years you start saving. OP sounds like they're struggling financially now so a suggestion of saving in 10 years time isn't helpful. It's more for long term.

Costwise A2A (especially after approaching grant) is the cheapest option here. Then maybe a combination of cheaper end battery + ToU tarriff for EVs with under 8p charging rates, these two should pay back much quicker.

Saying all of that it depends on so many factors, age, house size, shape, insulation, current fuel, electricity rates in the future, grants, ToU tarriffs, luck with battery lifetime.. and even interest rates.

sheenas

https://forums.moneysavingexpert.com/discussion/comment/81931136#Comment_81931136

I think the problem with your post are consistency. Further up for Jan. you said about 310kwh and above about half that? Then suddenly we on an EV tariff, Typical these offer cheap energy when we don't heat our houses and expensive when we do during the day (Octopus Go). Partially using A2A I can't see a need for overnight running. Paying of the cost of any investment is an important consideration, how quickly does the A2A take? Further anyone moving from gas is already pay 6-7p per kwh anyway.