Sunlight has been recognized as a powerful source of energy since ancient times. Magnifying glasses, used to concentrate the light of the sun into a beam, have been discovered in ruins as early as the 7th century B.C. The Greeks and Romans reduced the need to burn wood for warmth by taking advantage of the sun’s capacity to heat indoor spaces.
Today solar collectors are used to capture solar energy, which can be converted into electricity. Solar collectors can be active or passive. Passive solar collection means designing a home or building to take advantage of the sun’s energy. Active solar collection requires special equipment and technology to harness the sun’s energy. Active solar collectors include solar ponds, solar reflectors and photovoltaic cells.