How much does shadow affect in this case?

[kentdavidge]

I bought batteries, etc... the only thing left now is the solar panels. I'm thinking of mounting them on the garage roof for the sake of easy installation. The problem is the roof is just 4 meters high and is sorrounded by our large avocado tree and our two story house. There's shadow on the roof until 10 am. My plan is to buy three 160W panels. What do you guys think? Will performance be greatly affected due to the shadow?

 

[sunshine_eggo]

In your typical 60-72 cell panels, shading a single cell of a solar panel will kill 1/3 of it's output.

In portrait orientation, shading a SINGLE horizontal row of cells will cut the panel to near 0%.

Smaller panels can be even worse. It depends on the number of bypass diodes. I have some 100W Renogy panels that I'm 99% sure have NO bypass diodes in them as shading even a single cells takes output to 0.

Shade is to be avoided at all costs.

If you have unshaded exposure after 10am, it may be acceptable.

 

[kentdavidge]

@sunshine_eggo thank you. I can buy larger (higher power) panels, however I'm thinking of buying three 160W due to their smaller size, which will make things easier for me when installing them.

 

[sunshine_eggo]

@sunshine_eggo thank you. I can buy larger (higher power) panels, however I'm thinking of buying three 160W due to their smaller size, which will make things easier for me when installing them.

I can respect that. I'm still sore from installing 9 330W on top of my shipping container a couple weeks ago, and I had my son's help.

Does your intended location have unshaded exposure after 10am? If so, for how long? How much does this vary by season?

 

[kentdavidge]

@sunshine_eggo wow that must have been a lot of work. I hope it gives you the desired results. Yes, the sun is shining on it for the rest of the day, until about 4 pm. In Brazil we have a lot of sun hours pretty much the entire year.

 

[sunshine_eggo]

@sunshine_eggo wow that must have been a lot of work. I hope it gives you the desired results. Yes, the sun is shining on it for the rest of the day, until about 4 pm. In Brazil we have a lot of sun hours pretty much the entire year.

10a-4pm should yield the lion's share of what the panels can produce when compared to a full unshaded day.