How many sunny hours do we have?

RE: How many sunny hours do we have?

colporteur — Wed, 11 Nov 2020 15:38:09 GMT

I think it is the ideal project for someone considering investing in solar power. It would give you data that could help you analyse what you hope to achieve. I think it would be a good placement determination tool also.

Augh crap, I didn't realize the apartment building would cause me to lose exposure!

RE: How many sunny hours do we have?

ralphjy — Tue, 10 Nov 2020 15:41:13 GMT

To get a better idea of the effective solar irradiance make sure to mount your sensor in the same orientation (plane) that you would mount your solar panels. At higher latitudes there is a significant shift in the sun's incident angle from summer to winter. I'm at about 45 degrees N and I have a south facing roof with a 40 degree pitch, so I get a reasonable compromise between summer and winter performance. One depressing thing about tracking the data is that you get to see how many non-productive days you have during the winter [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-a5b1c705-e237-4ab9-9ecf-14992bb7a3ff/contentimage_5F00_2.png:16:16]. We had wildfires during September and I lost about two weeks of energy due to the heavy smoke in the area.

RE: How many sunny hours do we have?

dubbie — Tue, 10 Nov 2020 11:33:52 GMT

This looks interesting. I have messed about with solar cells and measuring sunlight intensity off and on for several years. One interesting feature is that the colder solar panels get the more efficient they become, so they actually work better in the winter when there is less light.

It is also difficult to get good data on sunlight intensity throughout the year so it will be good to see your data.

Dubbie