Explore the role and types of renewable energy, defined as an energy source that can be replenished by natural processes. Renewable energy sources include solar panels that convert energy from the sun, turbines that convert wind to energy, and dams that generate hydropower by controlling the flow of water. Geothermal heat (generated from heat sources in the earth’s surface), wave power, and wood are also renewable sources of energy.
Renewable energy sources are often touted as being more environmentally friendly than the other two major sources of energy: fossil fuels (such as coal, crude oil, and natural gas) and nuclear power. Environmentalists criticize reliance on the finite resources embodied by fossil fuels as well as the environmental degradation and pollution caused by their extraction, while many are concerned about the safety and long-term use of nuclear power, which produces radioactive material as a byproduct. Evidence that the burning of fossil fuels contributes to global warming also has some people advocating for its reduced use. Sometimes concerns regarding the use of fossil fuels are tied to crude oil price increases or the fear of being too dependent on oil-producing countries.
Critics of renewable energy argue that fossil fuels can provide energy at lower costs than renewable sources. There is also concern about the environmental impact of renewable energy. For example, the building of dams to generate hydropower results in the creation of floodplains and the rerouting of water sources dramatically impacts local human and wildlife populations. Critics of solar and wind energy note the exceptional amount of space taken up by panels and wind turbines, which negatively affects wildlife, particularly birds in the case of turbines.