How to calculate your own solar panel estimate for those wondering how we estimated those numbers for energy consumption and required number of solar panels here s the breakdown.
Solar energy watts per square foot.
The earth has 197 million square miles of surface which includes the surface of the oceans.
When dividing these values you obtain 0 35 kwh per square foot assuming 0 35 kwh for a 2 000 sq.
Sunlight has to go through the atmosphere and we find that the average clear sky sun provides around 893 watts m2 which is about 283 6 btu ft2 hr or very close to 100 watts per square foot.
Notice that this number is an average value and for a very high sun the numbers can be a little higher.
At this point you can use the calculation procedure described in the previous section.
However most installers estimate solar costs by the amount of energy needed at 2 53 to 3 15 per watt before any tax credits or incentives.
For the sake of example if you are getting 5 hours of direct sunlight per day in a sunny state like california you can calculate your solar panel output this way.
How much energy does a solar panel produce.
Considering 6 peak sun hours per day and 300 watt panels you need 16 to produce 700 kwh each month.
Below are cost estimates based on home size.
The solar energy reaching the earth is 12 211 gigawatt hour.
The cost of solar panels to power your house are 4 to 10 per square foot.
Number of solar panels per square foot of roof space.
Each solar installer has sophisticated software that can spell out your house s exact power needs while looking at historical weather patterns roof angles and other factors to tell you how many panels you ll need and how much power your they ll be able to generate per square foot.
System size kw square footage needed for low efficiency 16 square footage needed for medium efficiency 18 square footage needed for high efficiency 22 5 kw.
It may surprise you to learn that more than enough solar energy per square foot hits the earth to provide a solution for the entire energy consumption of the earth.
Direct estimates of solar energy may also be expressed as watts per square meter w m 2.
For a 300 watt solar panel with dimensions 64 inches x 39 inches 1 61 meters squared or 17 31 square feet the peak instantaneous electricity production per square foot at stc is 14 58 watts per square foot.
Radiation data for solar water heating and space heating systems are usually represented in british thermal units per square foot btu ft 2.
This is typical for residential solar panels being sold in the us in 2020.
Home the estimated electricity consumption is 700 kwh.
Cost of solar panels per square foot.
Thus the output for each solar panel in your array would.
This is measured in watt hours by scientists.