Solar

• Solar power harnesses the energy of the sun through roof-mounted solar panels or large solar arrays. This energy is then stored in batteries and photovoltaic cells until it is needed. A number of large companies have already installed large scale solar arrays to heat and cool their businesses, and others are expected to follow suit in the near future. Pfizer, for instance, operates a large solar-powered facility in Germany.
  
  

Wind Power

• The power of the wind can produce electricity, and large-scale commercial wind farms operate in the United States and throughout the world. One challenge of wind power, however, is getting the electricity generated from the largely empty spaces where wind is abundant to urban areas where power is needed.
  
  

Geothermal

• Geothermal energy harnesses the heat trapped within the ground to create electricity. The temperature within the earth varies widely, from very cold to over 300 degrees Fahrenheit. Geothermal energy uses that heat to turn turbines and power generators to make electricity. The most widely used type of geothermal plant today is the flash steam plant. This technology taps pockets of trapped water in excess of 360 degrees Fahrenheit and pumps the water to the surface under high pressure. The pressure is suddenly relieved when the water reaches the surface, resulting in large amounts of steam that in turn power generators and create electricity.
  
  

Biomass

• Biomass energy generation creates electricity from waste items like wood chips, cardboard and packaging materials. The state of California converts 5 tons of these waste products to electricity each year. These biomass products come from lumber mills, feed stocks and agricultural sources among others. A biomass power plant burns the waste and uses it to power boilers and create electricity. The California Energy Commission estimates that the state could deliver nearly 2,000 megawatts of electricity to its residents if all 60 tons of biomass generated within the state each year could be used for energy generation.
  
  

Nuclear Energy

• Nuclear plants produce no carbon emissions, and many experts feel that nuclear power must be a part of any move away from fossil fuels. Nuclear energy does have its challenges, including safety and the storage of nuclear waste, but many European countries, most notably France, already get a large percentage of their energy needs from nuclear power plants.