One of these alternative energy resources is wind power. Wind turbines continue to be developed that are progressively more energy efficient and less expensive. ?Wind farms? have been springing up in many nations, and they have even become more strategically placed over time so that they are not jeopardizing birds as former wind turbines did.

One of these is solar power. Solar power is driven by photovoltaic cells, and these are progressively getting less expensive and more advanced. Solar energy power can be used for electricity, heating, and making hot water. Solar energy produces no pollution, as its input comes completely from the sun's rays. However, much more work still needs to be done in order for us to economically harness the sun's energy. For the time being, the resource is a little too conditional?storage batteries are needed to be used as backups in the evenings and on inclement days.

Hydroelectric energy is available as a source of ?green? energy, and it can generate a substantial amount of power. Simply put, hydroelectric energy uses the motion of water?its flow in response to gravity, which means downhill'to turn turbines which then generate electrical energy. Needless to say, water is ubiquitous; finding sources for driving hydroelectric turbines is, therefore, not much of a problem. However, hydroelectricity as a source of ?green? energy can be complicated and expensive to produce. Dams are often built in order to be able to control the flow of the water sufficiently to generate the needed power. Building a dam to store and control water's potential and kinetic energy takes quite a lot of work, and operating one is complex as well, and conservationists grow concerned that it. Of course, a dam is not always needed if one is not trying to supply the electrical needs of a city or other very densely populated area. There are small run-of-river hydroelectric converters which are good for supplying neighborhoods or an individual office or home.

Geothermal energy is extremely abundant, since it lies directly beneath our feet, just a few miles beneath the earth's surface. This energy is produced by the heating of water through the actions of earth's fantastically hot molten core. The water turns to steam, which can be harnessed and used to drive turbine engines which in turn generate electricity. Great amounts of research and development should be put into geothermal energy tapping.

Waste gas energies, which are essentially methane, reverse the usual energy-pollution relationship by creating energy from waste that lies in the dumps and from some air pollutants. This gas is used in fuel cells and can be used in standard gasoline generators.

Ethanol is a gasoline substitute and is created from such things as wheat, sugarcane, grapes, strawberries, corn, and even wood chips and wood cellulose. There is controversy over this fuel with regards to its always becoming truly economical or practical except in very localized areas, but technologies for its extraction and admixturing are continuously being refined.

Biodiesel energy is created out of the oils contained in plants. So far, the commercial stores of biodiesel have been created using soybean, rapeseed, and sunflower oils. At the time of this writing, biodiesel is typically produced by entrepreneurial minded individuals or those who want to experiment with ?green? energy, but commercial interest from companies is on the rise. It burns much cleaner than oil-based diesel.

Atomic energy is created in atomic energy plants using the process of nuclear fission. This energy is extremely efficient and can generate immense amounts of power. There is concern from some people about what to do with the relatively small amount of waste product atomic energy gives off, since it is radioactive and takes hundreds of years to decay into harmlessness.

The splitting of an atom releases energy in the forms of both heat and light. Atomic power plants control the fission reactions so that they don't result in the devastating explosions that are brought forth in atomic and hydrogen bombs. There is no chance of an atomic power plant exploding like a nuclear bomb, as the specialized conditions and the pure Plutonium used to unleash an atomic bomb's vicious force simply don't exist inside a nuclear power plant. The risk of a ?meltdown? is very low. Though this latter event has happened a couple of times, when one considers that there are over 430 nuclear reactors spread out across 33 nations, and that nuclear reactors have been in use since the early 1950s, these are rare occurrences, and the events of that nature which have taken place were the fault of outdated materials which should have been properly kept up. Indeed, if nuclear energy could become a more widely accepted form of ?green? energy, there would be little question of their upkeep being maintained. Currently, six states in America generate more than half of all their electrical energy needs through nuclear power, and the media are not filled with gruesome horror stories of the power plants constantly having problems.