Solar, or photovoltaic, cells convert the sun’s energy directly into electricity, according to the National Renewable Energy Laboratory. The solar cell concept was discovered by Bell Telephone in 1954, when researchers realized that silicon reacted to sunlight, creating an electric charge, and applications for the technology continue to grow. Challenges with solar cells include their conversion efficiency and the number of cells needed to create a cost-effective electricity generating solution.
According to the U.S. Energy Information Administration, individual solar cells generate small amounts of energy, usually one or two watts. These cells were used in the 1950s to power satellites, and their use has expanded to include powering or charging many small devices, such as calculators, watch batteries, cell phones, music players and laptops.
When solar cells are grouped together, they form photovoltaic panels. Groups of photovoltaic panels are called arrays. Arrays are used to provide electricity to individual homes or businesses, or multiple arrays can be joined at a power plant and used to provide electricity to multiple users.
Small arrays power devices such as parking meters, traffic lights, water well pumps, electric fences and street lights, and provide the electricity required by natural gas and oilfield installations.
Photovoltaic groups and arrays provide electricity to areas that have limited access to traditional power sources such as natural gas or electricity. These applications are useful for remote locations on Earth, and they have an extensive history of use in space. According to the U.S. Department of Energy, solar cells were first used in space to power the Vanguard I satellite’s radio in 1958. Their use was expanded to powering all the electric systems of satellites shortly after Vanguard I’s success. Applications for solar cell technology in space continue to grow, including powering vehicles that move across planet surfaces and the use of solar panel “wings” to provide electricity to the International Space Station.
The National Aeronautics and Space Administration (NASA) has successfully designed and tested a remote-controlled, solar-powered airplane called the Pathfinder. Its wings are covered with a solar array that powers the plane’s electronic systems. Pathfinder is designed for imaging tasks and monitoring the effects of weather systems and natural or man-made disasters.
When solar cells are combined with another remotely available electricity source such as wind power, batteries or gas- or diesel-powered generators, the hybrid technology can offer advantages over a single technology solution. Combining complementary technologies allows users to maximize the power of solar cells while ensuring that electricity is available on cloudy days or at night, without relying on grid-supplied power.
About this Author
Gae-Lynn Woods worked in the international financial services world from 1990 until 2007. She now writes for Demand Studios, focusing on articles for eHow in the areas of business and gardening. She received her bachelor’s degrees from Texas A&M University and an M.B.A. in executive leadership from the University of Nebraska.