Best Solar System for me

PatrickO_3

We're thinking of installing solar panels. I've been doing a lot of reading around including looking at threads here. Still quite confused about how to work out the best system for our situation.

We have a detached house with an unshaded pitched roof facing SSE, and another roof facing NNW. Each roof could easily fit 12 panels.

Our heating and hot water is oil, with an electric shower. Electricity use was 3350kWh last 12 months. Being retired we're often at home during the day. No plans for an EV. We're in East Yorkshire.

We can't get a grant in our area, but we have savings we could use. I estimate the loss of compound interest on say £8000 over 10 years would be about £3500.

We've had different opinions from different local installers. One suggested maximising panels and a battery to get money back by selling to the grid. Another suggested we'd be better with a modest system and no battery.

What would be the best system to maximise return on investment over 5 and 10 years?

Is there a guide or method to work it out?

Screwdriva

I recommend panelling only the SSE aspect with as many 500W Eurener bifacial panels as will fit. If you plan to ditch oil, like so many have since the war, in favour of a heat pump, I would insist on a Tesla PW3 for the most future proof system possible.

Installers who recommend panelling the NNW really should explain that this aspect will generate less than 50% the power of the SSE aspect every year.

Newbie_John

If you buy UK gilts like T4Q you would get £4200 - so after 10 years you will have £12200.

Now panels, there are two income streams - own usage and selling, let's say 8kW set up makes about 8000kWh per year and you can sell it at 12p so about £960 - after 10 years if prices don't change you will have £9600-£8000 = so £1600 and panels. Probably little bit better as you would consume some at 25p price but I will skip it showing pessimistic case.