Quote:
Originally Posted by frquixote
I'm not quite sure where your numbers are off, but I have 28 225W panels from a well-known Japanese manufacturer (cells made in the USA!) that take up 380 square feet (35.28 sq meters) of roof space on my little (1172 sq ft) house and they generate on average 30 kWh/day, which is more than 850W/sq meter/day.
Having spent quite a bit of time studying the available solar panels before buying, I don't know of any that only generate 60W/sq meter/day ... that would be a 30W panel!!! I suspect you forgot to multiply the panel output by the number of hours it is actively generating power. Here in Hawaii we see an average of 5.8 hrs generating per day, but your output will definitely vary. Any solar panel salesman should be able to tell you what sun zone you are in.
And yes, it's easier to justify solar in Hawaii!  |
I could have some of it wrong as most of the data comes from sites that
promote PV systems.
So if you were able to get the full 7kwh of the net sunlight energy over a
day per square meter for your 35.28 sq meters = 246.96 kwh, but that would
be with 100% conversion efficiency. (And they must be assuming a 7hr day
at 1kW.)
If you could collect at the Peak incident energy at noon on a perpendicular
surface: 1 kW/sq.m, for your 5.8 hrs from 35.28 sq meters (5.8hrs x 35.28
sq.m x 1kW = 204.624 kWh per day, but that is not possible.)
I am assuming that your panels can't collect more solar energy than the sun
puts onto a sq. meter of the surface. Those I see in the 250W range have
a surface area close to a sq. meter. At their max output it takes four panels
to convert 1/4 of the solar hitting their surface into 1kW. 28/4=7kW.
7kW x 5.8hrs = 40.6kWh per day, if you could get the max output of all the
panels for the whole 5.8hrs.
Luck;
Ken