Awkward Silence Wtf!

Only available on StudyMode
  • Topic: Photovoltaics, Sun, The Panel
  • Pages : 3 (1042 words )
  • Download(s) : 250
  • Published : November 4, 2010
Open Document
Text Preview
A conservative value to use for a solar panel’s generating capacity is 10 watts/sq. ft.  This represents a panel conversion efficiency of about 12% which is typical.   That means that for every kW you need to generate, you’d need about 100 sq. ft. of solar panels.   If the sun would shine 24 hours a day, you could put up 100 sq. ft. of panels and you’d have enough to power an average home.  But as we all know, the sun doesn’t shine all the time.  The sun is only available during the day and the amount of sunshine per day is very dependent on cloud cover.   Also, the length of each day is dependent on the season. Fortunately, there are resources on the web to help you figure out how many hours per day on average you can count on the sun to shine based on where you live.  The numbers across the U.S. vary from an average of around 3 hours per day in places like Seattle, Chicago, and Pittsburgh to 5 or 6 hours per day in states like Colorado and California to a high of 7 hours a day in Arizona.   What that means is that the size of your solar panel array can vary from around 400 to 800 sq. ft. (i.e., 4 kW to 8 kW) respectively, depending on where you live.   You’ll need more panels if you live in a location that gets less average sunshine per day and fewer if you live in a location that gets higher amounts of average sunshine. If your utility company allows you to have net metering, that is, they supply you with a special meter that will spin backwards when you generate more electricity than you use, your annual bill can average out to be zero.  Because of the change in the length of the day in the winter months, you’ll likely be a net purchaser of electricity in those months and in the summer months, you may be a net producer.  A grid-tied system like I’m describing is different than off-grid systems, such as those used in remote locations with no electrical service, since those require batteries and that can significantly increase the overall system cost. At the...
tracking img