The commercial solar cells available today probably represent the state of the art for years to come. Good solar panels composed of monocrystalline silicon cells generate about 100 milliwatts per square inch (6.45 square cm). Commercial panels come in a variety of sizes, 100 watts and up; however, the power generated per square inch remains about 100 milliwatts. Number of panels required can decrease, but not the area.
How much electricity does an average 2-story 3-bedroom house use per day, per month or per year. The US Energy Information Agency has estimated that the average U.S. home uses 8,900 Kwh (kilowatt hours) per year or about 24 Kwh per day. If this average home is in a climate that will produce an average of 6 hours of sunlight for maximum power generation, each square inch of optimally oriented panels can produce 600 milliwatts per day.
Consequently, about 40,000 square inches (24000 watts per day / 0.6 watt hours per inch per day) or 278 square feet of solar paneling would meet household need. If purchasing a 100-watt panel measuring about 6 square feet, an average home would require 46 panels.
These calculations are for a fictional system but serve as a guideline. Your energy requirements may be substantially more, or less, than the average value used above. If your goal is to reduce your electricity bill to zero, you simply need to know your homes normal needs to tell you if it is possible and practical.
Electrical company invoices often show not only current months usage, but previous months as well. On request, the company may be able to provide a 12-month total. Alternatively, one can take meter readings each day over a week or even a month to include a few weekends when power use is typically higher.
Since usage typically is seasonable, this should be taken into account. For most of the U.S., winter usually represents the highest period of usage; however, in some areas of the country summers that require maximum use of AC may represent peak usage.
For example, if your energy bills or meter readings show that your yearly usage is 12000 Kwh per year, a solar power system would require a 63-panel array (47 x 12000 / 8900 = 63) of 100-watt panels. Roof space required would be 375 square feet.
Peter Wendt is a writer and researcher from Austin, TX with a goal to create a more sustainable home in the New Year. Wendt encourages his readers to speak with an Austin solar energy provider for more information about going green in 2013.
Article Source: How Many Solar Panels Do I Need to Power My Home?
DIY Solar Panels and Windmills Building Guides
Earth 4 Energy - Make your own solar panels or wind turbine. More info here
Home Made Power Plant - There are some other guides for DIY wind and solar generators, but all of those that I've read don't get into the same details. More info here