Sunlight is a pretty special thing. It wakes us in the morning, heats the earth during the day, helps plants grow, and provides us with some of the most beautiful moments of our lives – sunrises, sunsets, rainbows, etc. More and more, it is also providing us with electricity. On January 1st, the Cary News reported “If you’re in Cary, you may be solar powered,” as a public-private partnership flipped the switch on the town’s first solar power system. Solar farms are becoming an increasingly popular way to use tired farm land in North Carolina as evidenced by several recent articles on NewsObserver.com, but just how much energy can we really expect from the sun?
The meteorological answer depends on where you measure the incoming solar radiation. If you measure it at the beginning of its trip from the sun, the answer is 1,369 watts per square meter. If you wait until it reaches the surface, it averages much more manageable 198 watts per square meter. That amount depends on many factors such as cloud cover, season, the angle of the sun in the sky, and the reflectivity of the surface it hits. Snow is more reflective than grass, which is more reflective than blacktop. The more a surface reflects, the lower the amount of solar radiation that is absorbed. The average amount reflected from the earth’s surface is 30 watts per meter square and that leaves about 168 to be absorbed by the earth.
Improvements in technology are making the capture and conversion of the sun’s power as it reaches the earth’s surface easier and more viable than ever. With the push to find more environmentally friendly, renewable power resources, solar power is quickly becoming a popular option and North Carolinians are jumping on board. According to the Department of Energy’s website, doe.gov, North Carolina ranks 23rd in the country for renewable energy production with wind and biomass being our staples. As solar energy production continues to grow, we could move up in the rankings. Using the interactive D.O.E. map pictured here, we can see that if you put 100,000 square feet of solar panel surface area somewhere in the Triangle region, enough energy could be produced to power 1,183 homes.
So, what’s another potential benefit of sunlight? A cool house on a hot summer day.