Buying a Solar Panel Part 1

I've decided to try and get a solar panel fitted to our roof.

As you might expect, I like the fact that it'll cut our carbon footprint (about a tonne for a 2 kWp system), but I've also discovered it's a good investment: It should pay for itself in less than 9 years and, after that, it'll all be money in the bank.

And it'll give us some protection against fuel price hikes.

Trouble is, how on Earth do we go about getting one? How do we find a good installer? How do we work out if our roof is suitable? What size system? What questions do we ask the providers? How long will the system last? And so on.

FITs etc.

One of the things I've been looking into is what sort of income solar panels provide in the UK. It turns out that the return is made up of 3 elements: A Feed-In Tariff (FIT) from the government (currently about 43p per kWh); a payment from an energy supplier for the electric we export to the grid (3.1p per kWh); plus the value of electric we save when using the energy we're generating (maybe 14p per kWh). This might not sound like a lot but this could all add up to over £1000 a year tax-free and inflation proofed, for 25 years. More detail here.

Calculating What We Could Get

According to various sources, solar panels would give us around 9% return on our investment, a better return than any ISA account. This is why there are companies out there who offer to fit and maintain solar panels for free in return for getting all the FIT payments. In fact, if we couldn't afford to buy our own system then these free systems (aka "Roof for Rent schemes") would have been worth considering because they'd still cut our electric bills and carbon footprint.

Anyway, the point is, if it makes sense for companies to give away systems to get these FITs, it would also makes sense for us to own the solar panels ourselves (As long as we don't intend moving house too soon). As big as we can afford or, at least, as big as we can fit on our roof.

So I wanted to know what size system we could get.

For a while I couldn't figure out how to measure the available roof space. Then I realised I was looking at it the wrong way: Why not measure it from within the loft! Duh! I could even get the pitch angle of the roof. The result was at least 2.5 metres by 5, or 12.5 square metres with a pitch of 40 degrees.

I plugged these figures into this handy calculator and found out we could get a 1.5 kWp system that would give us a starting annual income of about £650, and pay for itself in 8 years and 10 months.

Next: So much for what we can get, but how do we get it? How do we find a reliable installer and what do we ask them? I'll be going into that in a few days.