Solar Energy

Solar energy is light from the sun, in the form of radiant light and heat, that can be harnessed directly or indirectly by a variety of technologies. This form of energy is being increasingly utilized in an attempt to meet society's need for power generation, and discussion of the feasibility of large-scale solar power production is likely to occupy a prominent position in the news media and public discussion for some time, as supplies of fossil fuels such as coal and oil diminish and global climate change (related to fossil fuel consumption) becomes a more apparent reality. It is important to note, however, that even without the use of technologies such as solar photovoltaic cells that “actively” exploit solar energy, solar energy affects us every day through the power it imparts to our weather systems, its heating of our atmosphere, and its acting as a source of energy for the natural world. Through the process of photosynthesis, plants capture huge amounts of solar energy annually.

Solar energy can be harnessed in two ways, either passively or actively. In passive design, an approach commonly used in architecture, designers orient buildings in such a way that they harness solar energy in the winter when it is cold and yet block the summer sunlight when it is hot. Devices such as solar-concentrating “cookers,” used in the developing world, are examples of simple passive devices. The other approach is to “actively” harness solar energy by using advanced technologies, such as solar photovoltaic or photochemical cells, to transform the solar energy into electricity—or in some cases into mechanical work (which in turn can also be used to drive a generator and produce electricity).