Green energy comes from natural sources such as sunlight, wind, rain, tides, wave, plants, algae, and heat inside the Earth. These sources have one thing in common – they are continuously replenished and will not be exhausted.
Fossil fuels such as oil, natural gas, and coal are the most widely used energy sources in the world, and yet they are finite. The formation of fossil fuels takes millions of years, and the extraction of them from deep beneath the Earth is often carried out in ecologically sensitive areas. Fossil fuels will run out one day, and when burned, they release greenhouse gases and other pollutants which accelerate global warming and climate change.
In comparison with fossil fuels, green energy has little to no environmental impact. Renewable energy technologies have been improved rapidly, and the material costs of solar panels, wind turbines, and other renewable energy equipment are also falling. Given the foregoing, more and more households and communities are able to generate their own electricity. Now, green energy can even replace fossil fuels for the energy use in our daily life such as heating and air conditioning.
Common Types of Green Energy
Solar Energy
Photovoltaic cells can capture sunlight and convert it into electricity. This is how solar power, one of the most popular forms of renewable energy, is generated.
Wind Energy
Wind turbines harvest the air moving across the Earth’s surface to produce energy, and they can be installed onshore and offshore.
Hydroelectric Energy
Hydropower relies on the movement of water in the water cycle, including evaporation and precipitation, as well as tides and water flowing through dams.
Geothermal Energy
Geothermal energy comes from the radioactive decay of minerals and heat generated during the formation of the planet. The massive amount of heat beneath the crust can heat the underground water and then create steam to drive turbines.
Biomass Energy
Biomass feedstocks are natural organic materials such as wood, sawdust, and combustible agricultural residues that can be converted into electricity and heat.
【Sources】
- National Geographic: https://www.nationalgeographic.com/
- U.S. Energy Information Administration (EIA): https://www.eia.gov/