solar energy

[lemur]

Does anyone know what the average amount of kilowatt-hours per month that can be generated per square foot of building area is? This would be a convenient way to estimate how much energy would be available per month for a solar-powered house based on its area.

[InigoMontoya]

All sorts of variables.

 

Latitude.

Altitude.

Humidity.

Pollution.

Probably others.... In any event, there's even a map of the results.

 

[lemur]

So a 1500sf house = @150m2, which could generate between 300kwh and 1200kwh per day, which would be 9000kwh - 36000kwh per month? But that's the total amount of energy from sunlight. So if you knew the efficiency of the solar panels, you could multiply the percentage, say 10%, and get 900kwh - 3600kwh per month. That seems like a high estimate, though, for some reason. If that's accurate, I think that would be a generous amount of power for a 1500sf house, especially if heating/cooling were not included. I found a website that estimates a household of 3 using 6000kwh/year (http://www.physics.uci.edu/~silverma/actions/HouseholdEnergy.html), which would easily be covered but I think that's just for San Diego which probably doesn't require much heating. Idk, could solar panels actually be sufficient to make every house energy independent?

Edited May 27, 2011 by lemur

[InigoMontoya]

Idk, could solar panels actually be sufficient to make every house energy independent?

Depends upon your definition of "energy independent." Keep in mind that you'll be doing a lot better in the summer than in the winter so while you may very well generate way more energy than you need in summer, you may not be in the winter.

 

Also note that the map in question was for 2 axis sun tracking. That's expensive and not likely to happen on a house. I know there are maps out there that assume 1 axis tracking or even just fixed arrays. The fixed array is more likely to be applicable to your question, but I just listed the first map that popped up via google.

[lemur]

Depends upon your definition of "energy independent." Keep in mind that you'll be doing a lot better in the summer than in the winter so while you may very well generate way more energy than you need in summer, you may not be in the winter.

 

Also note that the map in question was for 2 axis sun tracking. That's expensive and not likely to happen on a house. I know there are maps out there that assume 1 axis tracking or even just fixed arrays. The fixed array is more likely to be applicable to your question, but I just listed the first map that popped up via google.

My initial guess I would have made based on intuition vaguely garnered from reading about various arrays would have been around 300-500 kwh/month, so maybe that is closer to accuracy for a fixed rooftop array.

[InigoMontoya]

Here's a fixed array (set to latitude) map.