By Greg Scandrett January 4, Focusing on renewable energy sources other than fossil fuels and coals might help in avoiding environmental impacts, specifically from air pollution and GHGs. Nevertheless, all forms of electricity generation have their impacts. To achieve a low-carbon future, we need to understand the effects of different renewable energy resources. Renewable energy is derived from natural sources that are continuously and sustainably replenished. Renewable energy comes from wind energy, solar energy, biomass energy, biogas energy, geothermal energy, hydro power and offshore wind, wave, and tidal energy.
A wind turbine may have a lifespan of years, according to Thomas Gibon , meaning the material investments may last for years before needing to be replaced. Hydropower generation is vulnerable to silt buildup, which can compromise capacity and harm equipment. Drought can also cause problems. In the western U. Even hydropower at full capacity bears its own emissions problems, as decaying organic material in reservoirs releases methane. Dams aren't the only way to use water for power: Tidal and wave energy projects around the world aim to capture the ocean's natural rhythms.
Marine energy projects currently generate an estimated megawatts of power —less than one percent of all renewables—but the potential is far greater. Wind: Harnessing the wind as a source of energy started more than 7, years ago.
Now, electricity-generating wind turbines are proliferating around the globe, and China, the U. From to , cumulative wind capacity around the world increased to more than , megawatts from 23, mw—more than 22 fold. Some people may object to how wind turbines look on the horizon and to how they sound, but wind energy, whose prices are declining , is proving too valuable a resource to deny. While most wind power comes from onshore turbines, offshore projects are appearing too, with the most in the U.
The first U. Solar: From home rooftops to utility-scale farms, solar power is reshaping energy markets around the world. In the decade from and the world's total installed energy capacity from photovoltaic panels increased a whopping 4, percent. In addition to solar panels, which convert the sun's light to electricity, concentrating solar power CSP plants use mirrors to concentrate the sun's heat, deriving thermal energy instead.
China, Japan, and the U. Solar thermal energy is also being used worldwide for hot water, heating, and cooling. Biomass: Biomass energy includes biofuels such as ethanol and biodiesel , wood and wood waste, biogas from landfills, and municipal solid waste. Like solar power, biomass is a flexible energy source, able to fuel vehicles, heat buildings, and produce electricity. But biomass can raise thorny issues. Critics of corn-based ethanol , for example, say it competes with the food market for corn and supports the same harmful agricultural practices that have led to toxic algae blooms and other environmental hazards.
Similarly, debates have erupted over whether it's a good idea to ship wood pellets from U. Meanwhile, scientists and companies are working on ways to more efficiently convert corn stover , wastewater sludge , and other biomass sources into energy, aiming to extract value from material that would otherwise go to waste. On a large scale, underground reservoirs of steam and hot water can be tapped through wells that can go a mile deep or more to generate electricity.
On a smaller scale, some buildings have geothermal heat pumps that use temperature differences several feet below ground for heating and cooling. Unlike solar and wind energy, geothermal energy is always available, but it has side effects that need to be managed, such as the rotten egg smell that can accompany released hydrogen sulfide.
Cities, states, and federal governments around the world are instituting policies aimed at increasing renewable energy. At least 29 U. Other policies that could encourage renewable energy growth include carbon pricing, fuel economy standards, and building efficiency standards. All you need is your zip code. Power Profiler takes about five minutes to use. There are many ways to reduce the environmental impacts of your energy use.
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