Deriving energy from the wind has been used by societies for centuries to sail the ocean. According to Altenergy.org, Germany, the United States, Denmark and India are the leading nations that currently use wind to produce energy. Windmills or wind turbines are the primary technology used to convert wind into electricity. There are horizontal turbines that look like traditional windmills and vertical types that look like egg beaters. Since the speed and amount of wind determines the amount of energy produced, many wind power facilities are located in higher altitudes.
In 1830, British astronomer John Herschel was the first to use solar energy to cook food during an African expedition. The sun is the most-accessible alternative energy source and its rays can be converted into heat and electricity. The amount of energy produced is dependent on the day of the year, time of day and latitude. Photovoltaic devices, or solar cells, can change sunlight directly into energy and solar power plants use the sun to heat fluid to produce steam, which powers a generator.
Using water to produce energy has been in effect for many years. In fact, 7 percent of the electricity used in the United States is produced by hydropower. Hydropower uses the flow of water to produce energy. There are two methods by which this is done. One is the run of the river system, which uses the force of the current to supply pressure, and another is the storage system, whereby water is stored in reservoirs by dams. Although less commonly used, tides and waves can also be used to spin turbines to produce electricity.
Four percent of energy in the United States comes from biomass fuels. Biomass energy is produced when organic material is burned. Examples include wood, crops, manure and some garbage. Wood, the most common biomass energy source, has been used for years for cooking and heating homes. Crops such as corn can be used to produce biofuels like ethanol and biodiesel. The methane produced in landfills from garbage and other wastes is an important energy source found in natural gas, which is used for heating, cooking and electricity.