Solar and Bio Energy



Sunlight, the source of solar energy, is constantly available and renewable on Earth. Today, we use the sun's rays in many ways - to heat homes and businesses, to heat water and to power appliances. Solar cells, or photovoltaic cells, are made from silicon or other materials and convert sunlight directly into electricity. Solar farms can generate enough electricity to power thousands of homes by using mirrors to concentrate sunlight onto a large area of solar cells. 

Flowing water can be converted into electricity with generators. Most hydroelectric power plants are located at large dams that control the flow of a river. Dams block off the river and create an artificial lake or reservoir. A controlled amount of water is forced through tunnels in the dam. As the water flows through the tunnels, it turns into huge turbines and generates electricity.

Rivers flow all over the world, making the energy source accessible to millions of people. Hydroelectric power plants are a great help, but they also have massive disadvantages. Not only is the fauna disturbed by the turbine plants, but the flora also suffers from interference with nature. In addition, the water below the power plant may become scarce and thus has a massive impact on the environment. For hydropower, a flowing water source must be dammed up. If the water stops flowing, the habitats on the river banks disappear. This can even lead to animals no longer having access to the water.


Biomass is organic material that comes from plants and animals, e.g. crops, wood waste and trees. When biomass is burned, the chemical energy is released as heat and can generate electricity with a steam turbine. A major advantage of biomass is that it can be stored and used when needed. However, growing crops for biofuels requires large amounts of land and pesticides. The land could be used for food instead of biofuels. Some pesticides could pollute the air and water. Biomass energy can also be a non-renewable energy source. Biomass energy is based on biomass feedstocks - plants that are processed and burned to produce electricity. 

Biomass feedstocks can include plants such as corn or soybeans as well as wood. If people do not replant the biomass feedstocks as quickly as they consume them, biomass energy becomes a non-renewable energy source.