Renewable energies include:

• Wind energy: the energy obtained from the wind

• Solar energy: the energy obtained from the sun. The main technologies here are solar photovoltaic (using the light from the sun) and solar thermal (using the sun’s heat)

• Hydraulic or hydroelectric energy: energy obtained from rivers and other freshwater currents

• Biomass and biogas: energy extracted from organic material

• Geothermal energy: heat energy from inside the Earth

• Tidal energy: energy obtained from the tides

• Wave energy: energy obtained from ocean waves

• Bioethanol: organic fuel suitable for vehicles and obtained from fermentation of vegetation

• Biodiesel: organic fuel for vehicles, among other applications, obtained from vegetable oils

Who will be renewable energies benefit the most? Firstly, fast-growing, energy-hungry economies, who want power systems that are predictable, quick to assemble, easy to integrate and don’t damage the environment. Secondly, countries planning to widen access to energy, improve energy security and increase their energy independence. This is because new renewable-energy generators can become operational in less than two years. Compare this with an average of almost five years for the development of conventional power plants.

We divide our energy use among four economic sectors: residential, commercial, transportation, and industrial. Heating and cooling our homes, lighting office buildings, driving cars and moving freight, and manufacturing the products we rely on in our daily lives are all functions that require energy. If projections are correct, we’re going to keep needing more. In the United States alone, energy consumption is expected to rise 7.3% over the next two decades. Global consumption is expected to increase by 40% over the same time period.

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