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Renewable energy (also called green energy) is energy made from renewable natural resources that are replenished on a human timescale. The most widely used renewable energy types are solar energy, wind power, and hydropower. Bioenergy and geothermal power are also significant in some countries.
During the 20th century, energy consumption rapidly increased. Today, about 80% of the world's energy consumption is sustained by the extraction of fossil fuels, which consists of oil, coal and natural gas. [4] Another non-renewable resource humans exploit is subsoil minerals, such as precious metals, mainly used to produce industrial commodities.
Thomas Young, the first person to use the term "energy" in the modern sense. The word energy derives from the Ancient Greek: ἐνέργεια, romanized: energeia, lit. 'activity, operation', [4] which possibly appears for the first time in the work of Aristotle in the 4th century BC. In contrast to the modern definition, energeia was a ...
Human power is the rate of work or energy that is produced from the human body. It can also refer to the power (rate of work per time) of a human. Power comes primarily from muscles , but body heat is also used to do work like warming shelters , food, or other humans.
In 1802 lectures to the Royal Society, Thomas Young was the first to use the term energy to refer to kinetic energy in its modern sense, instead of vis viva. [3] In the 1807 publication of those lectures, he wrote, The product of the mass of a body into the square of its velocity may properly be termed its energy. [4]
Scholars have traditionally divided uses of animals, [1] plants, [2] and other living things into two categories: practical use for food [3] and other resources; and symbolic use such as in art [4] and religion. [5]
The sun's rays can be used to produce electrical energy. The direct user of sunlight is the solar cell or photovoltaic cell, which converts sunlight directly into electrical energy without the incorporation of a mechanical device. This technology is simpler than the fossil-fuel-driven systems of producing electrical energy.
Producing, transporting, or consuming energy all have an environmental impact. [3] Energy has been harnessed by human beings for millennia. Initially it was with the use of fire for light, heat, cooking and for safety, and its use can be traced back at least 1.9 million years. [4]