Renewable resource
From Simple English Wikipedia, the free encyclopedia
A natural resource qualifies as a renewable resource if its stock (quantity) can increase over time.
Natural resources which qualify as renewable resources are, for example, oxygen, fresh water, solar energy, timber, and biomass. But they can become non-renewable resources if more of them is used than nature can reproduce in the same time at that place. For example ground water may be removed from an aquifer at a greater rate than that of new water flowing to that aquifer. Removal of water from the pore spaces may cause permanent compaction (subsidence) that cannot be reversed. Human consumption and use at sustainable levels primarily uses renewable resources versus non-renewable resources.
Renewable resources may also include goods commodities such as wood, paper and leather.
Gasoline, coal, natural gas, diesel and other commodities that come from fossil fuels are non-renewable. Some commodities, like plastics and diesel, are mostly made from fossil fuel but ways have been developed for biodegradable plastic and biodiesel made from renewable resources such as corn, soybeans and canola.
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[edit] Types of renewable resources
[edit] Solar power
Solar power is the technology of obtaining usable energy from the light of the sun. Solar energy has been used in many traditional technologies for centuries and has come into widespread use where other power supplies are absent, such as in places far off from the national electrical grid and in space. Solar energy is currently used in a number of applications:
- Heat (hot water, building heat, cooking)
- Electricity generation (photovoltaics, heat engines)
- Desalination of seawater.
- Light
[edit] Wind power
Wind power is the conversion of wind energy into more useful forms, usually electricity using wind turbines. In 2005, worldwide capacity of wind-powered generators was 58,982 megawatts. Currently less than 1% of world-wide electricity use are produced by wind power, but in Denmark it is approximately 23% of electricity use, in Spain 9%, and in Germany 6%. Globally, wind power generation more than quadrupled between 1999 and 2005.
Most modern wind power is generated in the form of electricity by converting the rotation of turbine blades into electrical current by means of an electrical generator. In windmills (a much older technology) wind energy is used to turn mechanical machinery to do physical work, like crushing grain or pumping water.
Wind power is used in large scale wind farms for national electrical grids as well as in small individual turbines for providing electricity to rural residences or grid-isolated locations. Wind energy is ample, renewable, widely distributed, clean, and works against the greenhouse effect if used to replace the use of fossil-fuel.
[edit] Hydropower
Hydropower is the conversion of the energy of moving water into more useful forms. Already in ancient history hydropower was used for irrigation and milling of grain and afterwards also for textile manufacture and the operation of sawmills.
The energy of moving water has been exploited for centuries; in Imperial Rome, water powered mills produced flour from grain, and in China and the rest of the Far East, hydraulically operated "pot wheel" pumps raised water into irrigation canals. In the 1830s, at the peak of the canal-building era, hydropower was used to transport barge traffic up and down steep hills using inclined plane railroads.
Direct mechanical power transmission made it necessary that industries that used hydropower had to be near the waterfall. For example, during the last half of the 19th century, many grist mills were built at Saint Anthony Falls, utilizing the 50 foot (15 metre) drop in the Mississippi River. The mills contributed to the growth of Minneapolis. Today the largest use of hydropower is for electric power generation, which allows low cost energy to be used at long distances from the watercourse.
