Conventional power has enormously bad impact on nature: air pollution, drilling, mining, gas emission, combustion of natural gas, oil and coal etc. are only several of ways of harming environment when using conventional energy. To make energy production more environment-friendly scientists came up with the idea of green power, i.e. renewable energy resources with great environmental advantages. Green power alternatives are numerous, and new assumptions for alternative energy sources are made from time to time. The most commonly known green resources are solar energy, wind power, biogas, geothermal energy, biomasses, biofuel, and hydroelectric power. These types of sustainable energy are natural, so they demonstrate minimum pollution level. Though USA is currently dependent on conventional energy sources, the government is gradually ensuring programs for promotion of renewable resources. The hydropower use is wide-spread, and about 30% of the U.S. energy is produced with it.

The most widely used in households is the solar energy: solar panels are installed on roofs or other open-to-solar-spaces. The energy produced by the sun is frequently enough to use it for electricity or for illumination, and it is more wide-spread compared to, for example, wind power. Governments around the globe consider it possible to make solar energy a primary energy source by 2050.
The number of wind power users is constantly growing, especially in the states of Iowa, North Dakota, Minnesota, Texas, Oklahoma, Kansas, Wyoming, South Dakota, Nebraska, and Montana. These windiest states have great energy resources, so government and organizations invest into large-size wind-turbines, while people also invest in small-size wind-turbines for private usage.
Green energy is used not only for household needs, but is also available in the form of bio-diesel to run vehicles, and e-cars, like Toyota Prius, Nissan Leaf or Tesla, are gaining popularity, while solar-powered cars are also being researched and concept models, like Cadillac Provoq, are created.
Some types of green power are not so well-known by the public, but still they are useful and available for application. Probably the most underestimated powers are tidal and wave powers, but currently tidal generators are being installed in New York and along the Atlantic coast, as an experiment. These generators have no harm to ecosystem or environment, and introduce great potential for future production of energy. Wave power is produced at specialized wave farms by mechanical movements of buoyed devices. Such farms are only entering the green power scene, and they are quite seldom in USA and a little bit more popular in Europe.

In my opinion, alternative green power is a very important and urgent issue, and people should acknowledge that they are killing the planet in the process of getting conventional energy resources. Engineers and scientists have introduced and developed several different types of green power, and some of them are more viable and well-developed compared to others. As for me, among the most viable for being used in the future are solar and wind energy, hydroelectric power and tidal generators, which can actually make energetics absolutely eco-friendly.