Alternative+Fuels+cont.

__**Solar Energy**__ > >
 * Solar energy is the sun's rays that reach the Earth's surface which can be used for heat and electricity
 * When solar energy is converted in to thermal energy it can be used to:
 * Heat water- Used in homes, buildings, or swimming pools
 * Heat spaces- inside homes, greenhouses, and other buildings
 * Heat fluids- to high temperatures to operate a turbine and produce electricity
 * Two Ways to convert solar energy into electricity:
 * Photovoltaic Cells- These "solar" cells are grouped into panels and an array of panels can be used for a number of things from powering a calculator, a single home, or large power plants covering several acres of land
 * Solar Thermal/Electric Power Plants- Concentrate solar energy so it heats up a fluid and produce steam that is used to power a generator
 * Benefits: Do not produce air pollutants or carbon dioxide and if they are located on buildings they have little impact on the environment
 * Limitations: The amount of sunlight received on Earth is not constant and a large surface area is required to collect energy at a useful rate Citations


 * __Biomass__**
 * Organic material maded from plants and microorganisms which contain solar enegy as a result of photosynthesis
 * Exs. wood, crops, manure,
 * Can be burned for releasing heat which contains chemical energy
 * Can be converted into gases such as methane or transportation fuel such as biodiesel or ethanol.
 * Contributes 4% to the energy used in the U.S.in the form of wood, biofuels, and municipal waste
 * Researchers are trying to develop ways to burn more biomass instead of fossil fuels in order to cut back on waster and greenhouse gas emissions