How good are modern PV panels in cloudy/shady conditions?
Posted: Mon Sep 19, 2011 5:53 pm
I've tried all the usual Google searches & all I come up with is that "Yes, solar panels do work in cloudy conditions though not as well as in full sun" there is also a suggestion that they actually might work better in thin cloud where light is spread diversely particularly if your array doesn't face directly at the sun, no idea how true that might be.
So my Q is this, has anyone got any real life experience of how panels will produce under cloud or shade, eg as a % of normal max output.
I'm strongly thinking of going for the government scheme several of you have mentioned in other threads - prices have dropped, I have been offered an MCS installed 4Kw system for £11k, but my system will be in partial shade for a couple or 3 hours in the mornings (only when the sun is lower in the sky) due to surrounding trees; in midsummer, ie peak generating times the roof is hardly ever in shade at all. The trees obviously have less shading effect during Winter months when the leaves drop.
They have said they can split the array so the half of the roof which gets more shade won't cut down the output from the better side, as I understand output is limited by the lowest producing panels?
Any thoughts/observations are welcome - though considering the figures they base their projections on assume %age increases of around 3% pa in power costs & the electricity companies have recently hiked prices by 15% plus, the array would need to have a fairly dire performance for it not to make sense financially! or power costs would need to drop overnight!
So my Q is this, has anyone got any real life experience of how panels will produce under cloud or shade, eg as a % of normal max output.
I'm strongly thinking of going for the government scheme several of you have mentioned in other threads - prices have dropped, I have been offered an MCS installed 4Kw system for £11k, but my system will be in partial shade for a couple or 3 hours in the mornings (only when the sun is lower in the sky) due to surrounding trees; in midsummer, ie peak generating times the roof is hardly ever in shade at all. The trees obviously have less shading effect during Winter months when the leaves drop.
They have said they can split the array so the half of the roof which gets more shade won't cut down the output from the better side, as I understand output is limited by the lowest producing panels?
Any thoughts/observations are welcome - though considering the figures they base their projections on assume %age increases of around 3% pa in power costs & the electricity companies have recently hiked prices by 15% plus, the array would need to have a fairly dire performance for it not to make sense financially! or power costs would need to drop overnight!