Solar panels output

[Pete Houston]

Hi everyone. This is my first post here, I live in south-east Australia so the sun is at its highest to the north.

When we moved into this house 5 years ago there was already installed a 2kW system with panels on the north side (we've since added a 3kW on the west side). The inverter is an EKO 2000. Our neighbour on the north side has conifers that now completely shade the panels from about mid-May to mid-August. Keep in mind that the panels get no direct sunlight even on a sunny day. Outside of those dates, the panels work fine.

At this time of the year, when it is sunny, the panels, according to the inverter display, are generating zero electricity. When it's cloudy they produce between 350 and 500 Watts. Can anyone explain to me why this is, please?

I've thought of having them moved to the east side which gets plenty of sunshine into mid-afternoon but would it be worth the expense with panels that are probably about 10 years old?

[Rob Beckers]

Hi Pete,

I probably shouldn't move south of the equator: I'm so used to facing panels south it wouldn't end well...

Hard-shade, behind an object, is MUCH darker than the diffused light from an overcast sky. Think of it as a milky white lamp shade, that's what a cloudy sky does, diffuse sunlight so it goes in every direction. Having a blue sky and direct sunlight has light moving in just one direction, put anything in between and there's nothing else coming in from the sides (as it would with clouds).

By the way, trees on neighbours lots that block light to solar panels have been known to mysteriously die. :amazed:

-RoB-

[Pete Houston]

Hi Rob, thanks for your response. I was thinking it might be something like that; have noticed on really hot days (we can get 40°C+ here occasionally) that if there's a thin layer of cloud, the panels output is higher than it is with a clear sky.

We've just had 10 wet days, some of which were really dull (we're only two weeks away from our shortest day), and it was quite weird to see the 2kW system outputting so much power when there was no sign of the sun.

Have thought about the trees mysteriously dying but I'm pretty sure suspicion would fall on me!

[Russel Delainey]

It might sound obvious, but have you talked to your neighbor? If you are willing to cover the cost, he may be willing to trim the top of those trees.

Nothing to lose by asking.

[Pete Houston]

Hi Russell. Sorry for the delay in responding. It's the first time I've checked back since Rob's reply.

I have spoken to the neighbour and he wants to get them trimmed too. However, the cheapest quote was A$10,000! Much cheaper for me to get the panels moved.