Solar Energy – Our sun is the greatest source of energy we know about it today, it comes to us freely and is efficient. It is very possible that solar power can replace traditional electricity sources in many places, especially where there is abundant sunshine. Unfortunately not all places are ideal for solar power. In the areas at high latitude there is not enough sunlight in a day to produce efficient energy, and the same for places where it rains a lot.
Wind Energy – Wind is very efficient at producing electricity. Obviously you need a lot of wind, like along coast lines and at high altitudes. Wind power could replace up to 20% of our total electric consumption in the foreseeable future. Wind is a clean source of energy with none of the harmful byproducts like carbon dioxide. However the huge blades of the windmills do pose a danger to birds and you need a lot of room to build a sufficient number of windmills.
Hydroelectric Energy – This type of power is mainly sourced from dams. The production of electricity from the water movement is clean and it does not produce waste material. However, the ideal type of places to build this is very limited and it is very expensive to build the dams.
Tidal Energy – Tidal energy work much in the same way as hydroelectric energy, but on a smaller scale, and it uses the natural tides of the ocean. There are several drawbacks though. Because of the sometimes violent and unpredictable nature of the ocean, they can not be constructed in many places. So far only about 9 places have been identified to build this kind of power plants. And these power plants can have a negative impact on migratory birds and also fisheries.
Biomass – Biomass can be used to produce an alcohol that is comparable to coal and can be used to replace our gasoline needs. The biomass may consist of fermented animal waste, agricultural crops, grains and other natural products. However, using the resulting fuel still produces greenhouse gases.
Other forms of energy such as fusion, geothermal and nuclear power can power the world, but they all have some negative impact on the environment.
It seems all forms of alternative energy have some drawbacks, but they all are better options to replace our current dependency on coal and oil.