Wind

• Turbines are tall structures with propellers at the top; the wind turns the propellers which turns a generator, creating electricity. These are often built together in a wind farm, located in areas that receive strong and regular wind. The major downside is that it is not always windy, so this energy source can only ever be part of the solution.
  
  

Hydroelectric

• This works by releasing dammed water to drive a turbine and power a generator. The energy is taken is from the gravitational fall and flow of the water, and the amount of energy produced depends on the amount of water released and the difference between the height of the water and the turbine. The release of this water can be controlled, so the energy source is available on demand. It also only creates a small amount of greenhouse gases. However, building one of these large reservoirs can be expensive and often requires people to be relocated to new homes to make room for the structure.
  
  

Solar

• Some see solar energy as the energy of the future, one reason being that its source, the sun, is not going anywhere so it provides a reliable, constant source of energy. People can easily install their own solar panels to generate energy to heat and power their homes and provide hot water or heat pools. Although it can take several years to recoup the initial cost of installing solar panels, many people find that solar energy creates more electricity than they need, which can then be sold back to the utility company for an extra financial benefit.
  
  

Biofuel

• Energy taken from plants is called biofuels; they can be gases or liquids and power cars, heat homes and generate electricity. Biofuels are renewable and create a low level of emissions. Algae biodiesels are one of the more promising biofuels as they generate 30 times more energy per acre than any other biofuel. Ethanol is the most common biofuel; it is distilled from certain crops, such as corn. Other promising crops for biofuels are switchgrass and sugarcane.