Ashley R. Singer
The way hydroelectric power works is by using the natural flow of water to spin a turbine attached to a generator which makes electricity. There are several ways in which water flows; down waterfalls, through a dam created by a reservoir, down a river, and in and out by tide.
Wind power uses large turbines, placed in strategically chosen locations, to catch air moving over the earth's surface. There can be either one or a few wind turbines to supply energy to the site at which the turbines are located, or hundreds of turbines that supply energy to a community.
Geothermal power is made by using the heat radiating from the earth. To get through the earth's layers to the heat, a large tunnel is drilled out about 2 miles deep. Either subterranean water is relied on or redirected water from a near by river is used to make steam from the geothermal heat. The steam then can be used directly to heat a building or can be used to spin a turbine connected to a generator to make electricity.
There are two types of solar energy: photovoltaic and thermal. Photovoltaic solar power is what we commonly use in calculators. It can also be placed on top of roofs or any place that can get sufficient sunlight. When photons from the sun hit photovoltaic cells, electrons, from the atoms of the photovoltaic cells, are set in motion creating electricity. This electricity can be used to power the house they are on and give back energy to the power grid. Thermal solar power uses the heat from the sun. Solar panels with copper pipes carrying either water or an anti-freeze solution are placed on a roof. The sun's radiation heats up the liquid inside the copper piping sending it into the house. The water running though the pipes can be sent to a hot water heater or into a pool. If anti-freeze is in the piping it can be used to heat the house in the winter.
