Everyone is familiar with those small solar powered calculators and other devices that rely solely on the sun for power. As long as there’s enough light, they seem to work forever. You may also have seen larger versions of those solar panels, perhaps on roadside installations meant for powering emergency signs and call boxes.
So, how do solar panels work? They use something called the “photoelectric effect,” described by, you guessed it, Einstein. In brief, PV panels are made from semiconductor materials that give off electrons—energy – when excited by light. How many electrons you get depends on the efficiency of the panel. Most commercial and domestic solar panels convert about 20 percent of light energy into electricity, while pricey solar panels used by NASA for satellites can be up to 40 percent efficient.
The hope for a “solar revolution” has been floating around for decades. However, as solar costs plummet, U.S corporate giants including Apple, Google and Wal-Mart are turning to the sun to power stores, data centers and other facilities. President Obama cited a Wal-Mart store in Mountain View, California on its commitment to double the number of solar energy projects at its stores, Sam’s Clubs and distribution centers nationwide by 2020.
Google announced a $1 million prize to develop the next generation of power inverters to bring solar to more U.S homes. And Apple has pledged to power all its facilities with green energy. “These companies are expanding their use of solar because it makes sense from both business and social-responsibility viewpoint,” says Rhone Resch, president of the Solar Energy Industries Association, an industry group, noting 30 utility-scale projects are under construction.
Recently, General Motors has joined the expansion of solar power energy in its facilities. The company installed 150-kilowatt ground-mount solar arrays to its processing center in Swartz Creek and engine plant in Flint. The arrays are expected to generate a total of 400,000 kilowatt hours of renewable energy per year to the facilities’ grids, which is equivalent to the annual energy use of 25 homes.
“Not only does it reduce our emissions and lessen our dependence on petroleum, it makes a statement about the role businesses can play in securing a clean energy future,” said Rob Threlkeld, GM global renewable energy manager. After GM completes the projects this fall, the company will house more than 39 megawatts of solar power at 13 facilities around the world and more than 60 megawatts of renewable energy globally when combined with its landfill gas and biomass energy use.
The initial costs of installing and maintaining solar panels is lower than ever before and pretty soon homeowners are going to start wondering why they are paying so much for city power when they could be getting it from the sun for a fraction of the cost. With more of the world’s attention on the advancement of renewable energy sources than ever before, some of the greatest minds have been taking a long, hard look at our current solar technologies. As technology continues to grow and therefore improve solar energy systems, more homeowners will begin to see solar power as not only viable, but crucial to their existing energy needs.
So, it looks as though solar power may be seeing an unprecedented surge in 2014, only about 100 years after the photoelectric effect was first identified. Well, better late than never, right?