Solar/Battery/ASHP/EV - what should I get?

Solar_Battery_user

Big_Blind said:

Hi,

I want to save money on my energy consumption. I could virtue signal about carbon footprint and, whilst that may be an additional benefit, it’s all about the £££.  My ideal scenario is that someone else pays, eg the government but, as that looks unlikely, my next best option would be for any monthly repayments for the cost of a system to be largely offset by the savings or from money selling back to the grid so that once the loan is repaid I’m getting lots of free electricity. 

So, I decided that solar panels would be a good idea. I had a guy out to do me a quote and, if anything, what he told me put me off slightly. He told me that the panels would generate using UV so if it was cloudy that’d have no impact on the electricity generated. He even upped the ante by telling me the panels would continue to generate electricity at night due to the sun bouncing off the moon. I really don’t like it when salespeople make outlandish claims as it makes me trust them less. 

The question is whether I should go all-out and replace my combi boiler with an ASHP given that grants pay a large chunk at present? But, gas is still relatively cheap so I’d have to be confident it was worth it given that I can sell excess energy generated back to the grid so wouldn’t need to use it for heating. 

There are other factors like whether I should get battery storage? I have no concerns about outages so it’d be purely to store excess energy or, in an ideal world, charge when the electricity is cheap and then sell back to the grid at more than I paid for it? That’d also mean choosing the best tariff - maybe Oxyopus Flux? But, then it looks like EV batteries may make that battery redundant? Our car is on our drive most of the time. We need to get a new car soon so will likely get an EV but won’t do many miles. It’s unlikely to have V2G comparability but I can see us getting one that does in 3 to 5 years time at which point we’d have a battery up to 20x the size of the one we’d get as part of our solar system. So, would we be better avoiding the outlay and using a tariff like Octopus Go?

My current temptation is to get the solar panels (12x444w) with inverter (3.6kw) and battery (5.3kw). I’m tempted to look into an ASHP, especially if it can cool the house in the summer. I hate the heat as much as I hate the cold. 1C above or below 19C is ideal for me. But, I do think we’ll get an EV in 6 months so it’d be nice to make that work for us. Then, in 3 to 6 years maybe get one that’s compatible with a smart tariff and can be used to buy and sell power?

So, am I missing anything and what would you go for? Happy to answer any questions as best I can, including giving details of exactly what I’ve been quoted. 

Solar panels with 10kWh battery would be my choice if you really would like to reduce your electricity bills.

We got 5kW solar(12 panels) and 10kWh Solar Edge storage battery. Before the solar panels and the EV we were paying £120 to £150pcm for electricity, which is around ££1,500-£1,800 per year. In September 2023 the EV arrived and the bills went more than £200 to £220pcm. I am on Octopus Intelligent Go and the EV charges at 7p per 1kW.

After the solar installation of 9 panels and 10kWh Solar Edge battery for around £11K in Jan 24 our electricity bills went down to £693 for the whole 2024 for 9,190kW Import from the grid . Most of the electricity is for the EV at 7p.

Octopus pays 15p per 1kW export.

Without the solar our bill would have been £2,500, after the solar is £700. This is £1,800 saving for the first year. If it continues like that in 6-7 years the solar system would be paid for.

The battery makes a big difference. Get the highest capacity battery you can afford.

From July 2025 we added 3 more solar panels. Total 12 with 5.36kW power. We are able to export more energy now and in a sunny days we almost do not use anything from the grid between 05:30am and 11:30pm. During the 6 hours 11:30pm and 05:30pm our rates are 7p and we charge the battery the EV's and try to run the DW after 23:30.

I have a gas combi for heating and hot water. Got a quote for a heat pump, but not sure will go with it.

My calculations include the export with Octopus. 

For example the latest electricity bill I have is for the period 10th August till 9th September 2025 I have used 880kWh electricity and 866 is on 7p. Total charges with £13.22 standing charge is £78.60 and my export for the period was 589kWh at 15p, which is £88.28.

I have a negative bill for the period of -£9.68, which will go as a credit on the account. Without the solar and battery, I would have most of the 880kWh on 27.97p and that would have been much more expensive.

I would highly recommend the company which installed our system. They were very good and they are based in Surrey and cover South and South West London if you are interested or have questions, please reply.