We like renewables a lot. We think they have a role to play in the UK’s energy future, on both large and domestic scale. We know technology’s improving all the time at domestic scale, and we’re very happy that the market for technologies like solar panels seems to be swelling up nicely in the UK, making them available for more and more people.

These things won’t come as a surprise to too many people we shouldn’t imagine, but we just thought we’d drive home the point, just in case anyone thought the current media interest in our data on solar PV meant that we’d joined the ‘anti’ brigade.

Not a chance.

We have indeed moved our expectations of average electricity bill savings from solar PV downwards a bit, but then, our job is to be open, honest and in independent, so buyers of these technologies can make rational choices. But why the change?

Well, we follow the latest industry research with interest – you need to if you want to keep on top of the numbers in the energy game – and lately we’ve been seeing trials of other technologies, which you’d expect to export much less back to the grid than solar panels,  show lower levels of electricity used in homes than expected i.e. a greater amount fired back onto the grid without even flirting with an appliance.

This is little to do with the technologies themselves and a massive amount to do with the way people use the electricity they’re generating, but naturally, we’ve altered our expectations of solar PV bill savings accordingly – to around £70 a year.

Of course, this is an average, and with Feed-in Tariff payments made for both generating and exporting back to the grid, solar panels are still a fine investment – equal to or better than most building societies, in fact. And while these are typical estimates, it’s quite possible that someone could save more than £70 on their electricity bill if they were at home in the day, or set all their appliances to run in daylight hours, so that they maximised their use of the solar energy they were generating.

Of course this raises other questions – namely, whether ‘free solar’ really is the bonanza it looks like it might be. The answer to this effectively is: it depends.  The central consideration when signing up to a ‘rent a roof’ deal is to remember that you’re not going to get the Feed-in Tariff, so whether it’s a bargain or not rests  on how much you’re at home and when you use your appliances. For pensioners or people who spend time at home during the day, for example, free PV would likely provide a much bigger saving than £70.

As Mr MoneySavingExpert himself, Martin Lewis, says:

It’s still worth remembering over the long-term, five to 20 years, energy prices are predicted to rise significantly, as regulations push providers into being much more sustainable. If that does happen, the savings from free panels should increase.

Finally, it’s important to point out that this change in our data assumption isn’t saying that solar PV isn’t good at generating electricity – in fact, the technology itself is getting better and better as the market builds. We’re just accommodating what we know now about how people actually use the electricity they get from their panels; for want of a better phrase, ‘keeping it real’. So long as solar installers, particularly the ‘free’ ones, are doing the same, then there’s no great solar crisis to worry about here.