DrFfybes wrote:Lanark wrote:Solar PV cells work based on light and not with the heat of the sun; hence it hardly matters if it is cold, cloudy or foggy.
Cold makes no difference, the other 2 a massive one. You need bright direct uninterruptes sunlightto get a decent output.Lanark wrote:Scotland gets a similar amount of irradiance to Germany, which has the largest PV market in the world.
In the summertime the sun can stay up until after 10pm though in the winter it can disappear at 4pm so the issue is about generating supply at times when it isn't needed.
The incidental angle of the sun also makes quite a difference. The further North you go the lower the angle of the sun, markedly so away from the midsummer.
A friend in Perth gets similar total output to me in summer apparently (looking at August last year) but since then has lagged. He's catching up now, but even with his longer daylight it seems the hours of bright direct sunlight are not really any longer and his incidental angle is lower than ours.
https://www.timeanddate.com/sun/uk/shrewsbury lets you play with locations, even with our largely East facing array output declines dramatically an hour or so before daylight ends as the sun drops.
Maybe he needs a steeper roof.
Paul
Totally agree!
cloud is THE solar killer (and can be tricky to cope with in MPPT schemes)
Then angle - you want the rays normal in incidence to minimise reflection; depending on the array and use case it might even be worth motorising the panels for this
Temperature has an effect but less so than on batteries that are normally deployed with the panels I've had to play with