What is renewable energy? Energy consumption currently relies on coal, oil, and natural gas. Fossil fuels are non-renewable, which means that is a finite resource that will eventually decrease and become too expensive and more environmentally damaging. In contrast, renewable energy resources are constantly replenished and accessible. Renewable energy technologies should strive for cleanliness and have the lowest environmental impact compared to conventional energy technologies.

Summary

Solar Energy:
The sun is the main source for most renewable energy forms. Solar Energy incorporated the use of photovoltaic (solar cell) technologies. It can be used directly as heating and cooling system, as lighting device, as electricity generator or in a variety of other industrial purposes.

Wind Energy:
Through the use of wind turbines mounted on a tower at 100 feet, wind power is captured and converted into useful form, such as electricity. This technology or wind turbine can be used as stand-alone applications for water pumping or communications. It can be also connected to the power grid or combined with solar energy systems. A plant with numerous wind turbines is required for large-scale demands of energy.

Hydroelectric Power:
Hydroelectric Power or Hydroelectricity is electricity generated by water power. This technology requires the construction of hydroelectric plants to harness the force of large amount of falling or moving water. It is the form of renewable energy most commonly used and has proved its efficiency and low impact to the environment, compared to fossil fuel powered energy plants.

Hydrogen Energy:
Hydrogen is the simplest and the most plentiful element in the universe. It is constituted when combines with other elements, as the example of water, a combination of hydrogen and oxygen (H2O). It is found in many organic compounds, or hydrocarbons, component of most common fuels such as as gasoline, natural gas, methanol, and propane.

Hydrogen is a high source that produces no pollution.
Hydrogen Energy Technologies have developed the use of fuel cells, a combination of hydrogen and oxygen to produce electricity, heat, and water. Besides its applications in the domestic and industrial arena, it remains a promising solution for electric motor vehicles.

Nuclear Energy:
The technology to pursue safe and reliable nuclear power in an environmentally responsible manner is another important option to reduce our carbon footprint and reliance on fossil fuels. Given the vast proliferation of nuclear power world-wide, its cleanliness, efficiency, and low cost, surely nuclear should not be "off-the-table".Concern over long-term uranium supplies have stimulated interest in fuel reprocessing and alternative nuclear fuels, such as thorium. Deployment of advanced reactor and fuel cycle technologies could increase the long-term availability of nuclear energy from a century to thousands of years. Worries over nuclear waste has championed technology to reprocess it as a resource to generate additional energy.

Geothermal Energy:
Geothermal Energy Technology requires the use of heat pumps that tap the Earth's internal heat. It can be used as electric power generator, or as heating and cooling system. Different methods are applied by geothermal power plants. They can drill into the underground reservoirs of wells and use steam or hot water to power a turbine/generator, among others.

Ocean Energy:
Ocean Energy Technologies are basically derived from two types of power: thermal (ocean’s temperature) and mechanical (ocean's waves).

Ocean Thermal Energy uses a system of turbines propelled by the temperature changes between the ocean’s surface and the deep water. Through different methodologies, these turbines activate a generator that produces electricity.

Ocean Mechanical Energy harnesses the alternating energy of waves, driven by both the tides and the winds. In order to produce electricity conversion, this technology requires the use of mechanical devices (a barrage or dam). These devices act as a barrier and force water to pass through the turbines that then will activate the electricity generator.

Sources

U.S. Department of Energy

Alliance to Save Energy

International Energy Agency

Leonardo Energy

Farm Energy.org