The main idea is to use very little of the expensive semiconducting PV material while collecting as much sunlight as possible. But because the lenses must be pointed at the sun, the use of concentrating collectors is limited to the sunniest parts of the country. Concentrating collectors can be designed to be used with tracking devices, but this further limits their use to electric utilities, industries, and large buildings. The performance of a PV cell is measured in terms of its efficiency at turning sunlight into electricity. Only sunlight of certain energies will work efficiently to create electricity, and much of it is reflected or absorbed by the material that makes up the cell.
Low efficiencies mean that larger arrays are needed, and that means higher cost.
The cost for personal solar power systems is rapidly decreasing and recent opportunities to sell excess electricity back to the electric company are making solar electricity generation an important option. The environmental impact of generating electricity from biomass varies greatly depending on the fuel source and the technology used. Presently, burning municipal solid waste does not qualify as a Green-e resource. Using biomass resources to generate electricity can help support agricultural and farmland preservation and can also solve other environmental problems by getting rid of existing wastes in a relatively clean and safe way. Back to top Using Landfill Gas to Create Energy Landfill gas is created when municipal solid waste in a landfill decomposes.