Solar Energy

• Solar energy has been around longer than many people realize; it was first discovered by Edmund Bequerel in 1838 that when certain chemicals are exposed to sunlight, an electrical current is produced. Solar energy is especially popular among environmentally conscious consumers since it emits no pollutants. Solar energy can be used both commercially in solar farms of large arrays of solar panels, and residentially with rooftop panels. Solar panels are not terribly productive at generating power, as the most efficient panels are only about 30 percent efficient.
  
  

Hydroelectricity

• An older form of power generation, hydroelectric power is when a flow of water spins a turbine to produce electricity. There are two types of water turbines: impulse and reaction. Impulse turbines are spun by a jet of pressurized water, while a reaction turbine is completely submerged. Since there is effectively an unlimited supply of water on the planet, hydroelectric power is considered a renewable resource. Water turbines can be installed in rivers, sounds or even along jetties and lagoon inlets to take advantage of predictable and reliable tidal forces. Hydroelectric power is generally only used near bodies of water so that it does not have to be transmitted over long distances.
  
  

Nuclear Energy

• Nuclear energy is a controversial form of power generation due to public concerns about safety and disposal options of spent fuel. Nuclear energy generation is similar to coal generation in that fuel is used to turn water into steam, which then spins a turbine to generate electricity, but the heat generation is vastly different. In nuclear reactors, uranium atoms are split to release large amounts of energy. As of 2011, there have been no new nuclear plants built in the United States since 1996, as disasters in Chernobyl and Three Mile Island have made the Nuclear Regulatory Commission wary of building new plants.
  
  

Wind Power

• Much like hydroelectric power, wind power is produced by a flow of air pushing against a turbine blade. Wind turbines are placed in locations that have notoriously strong and consistent winds, such as hilltops and offshore areas. Turbines are mounted on high towers so that they sit in the most stable wind, as currents close to the ground can have turbulence that disrupts the turbine's power capacity. Some office and residential buildings operate their own wind turbines, and some wind farms provide power to electrical utilities.