Environment

What is Renewable Energy?

The term renewable energy is used to describe energy that is obtained from natural resources

Renewable energy is described as energy obtained from natural resources that do not deplete. Sustainable and not causing high pollution, sources of renewable energy include sunlight, wind, water, biomass, and tides. Renewable energy is used for a variety of industrial and domestic activities. Many countries have been substituting non-renewable energy for renewable energy due to the latter’s low environmental impact.

What is Renewable Energy?

Wind

In 2015, about 35% of renewable energy derived in the US came from wind power. Wind farms are mainly situated in areas with strong and constant winds including high altitude areas as well as offshore. Wind turbines tap the wind’s kinetic energy and convert it into electric power. In 2015, electricity from wind power accounted for about 4% of the world’s electricity demand. In addition to the US, countries in Europe such as Denmark, Portugal, and Spain as well as Canada and China have been on a mission to increase their wind power capacity.

Biomass

Biomass is another renewable energy source, and it is obtained from living or recently living plants or in some cases, animals. To obtain energy from biomass, it can either be combusted or converted into several forms of biofuel. Thermal, biochemical, or chemical methods are used to convert biomass into biofuels. The largest percentage of biomass used comes from wood. Several plants are grown as sources of industrial biomass including sugarcane, switchgrass, corn, bamboo, willow, and miscanthus. Ethanol, methane, and biodiesel can be obtained by converting biomass. In 2015, biomass accounted for 11% of the renewable energy derived in the US.

Solar

Several technologies have been invented to harness solar energy including solar architecture, solar heating, artificial photosynthesis, and concentrated solar power (CSP). Solar technologies are grouped into two categories, namely passive and active. Designing spaces to facilitate the natural circulation of air or using materials with light dispersing features are some examples of passive solar technologies. Active solar techniques include converting light from the sun to electric power, using solar collectors for heating purposes and solar thermal energy. The conversion of sunlight to electricity can be done by using photovoltaics (PV) or concentrated solar power (CSP). 5% of solar energy was obtained in the US in 2015.

Hydroelectricity

In 2015, hydropower generated 4% of energy in the US. Hydropower stations are used to generate power in almost 150 nations in the world. Countries in the Asia-Pacific region generate the highest percentage of the global hydropower production. Historically, hydropower production was done by building large dams and reservoirs along the length of water bodies. More and more countries have embraced small hydro installations and run-of-the-river hydroelectric stations. China holds the title of the world’s largest hydroelectric power producer. In 2010, hydropower accounted for nearly 17% of the country’s domestic electricity use. Wave power and tidal power are emerging as other forms of hydropower. Wave power relies on the energy of ocean surface waves while tidal power taps the energy of tides.

Geothermal Energy

Geothermal energy comes from earth’s thermal energy which can be obtained from shallow ground, hot rocks or water found a few miles deep in the ground. It can be sourced as deep as 4,000 miles into the earth’s core where very high temperatures cause the rock to melt forming magma. Geothermal energy can be used to heat buildings, water and can also pasteurize milk. 3% of geothermal energy was obtained in the US in 2015.

What is Renewable Energy?

RankRenewable Energy Type Percentage of Energy Derived (United States, 2015)
1Wind 35
2Biomass11
3Solar5
4Hydroelectricity4
5Geothermal power3

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