Bucharest 2011

Şcoala cu clasele I-VIII nr.186 Elena Văcărescu

TeacherTudor GEORGETA

Nonrenewable Nonrenewable – their supplies are limited examples: Coal, petroleum, natural gas, propane, uranium .

Renewable-Renewable- they are naturally replenished. examples : biomass, geothermal energy,

hydropower, solar energy, and wind energy

renewable energy source

generated by the wind power

-air movement due to irregular warming of Earth surface

by the sun

- The Oldest Windmills Were in Ancient Persia

-as early as 5000 B.C-Wind energy propelled boats along the Nile River

-200 B.C.-simple windmills in China were pumping water

-in Persia and the Middle East – windmills for grinding grain

-11th century, people in the Middle East were using windmills extensively for food production

returning merchants carried this idea back to Europe

The Dutch refined the windmill and adapted it for draining lakes and marshes in the Rhine River Delta

-19 th century - settlers took this technology to the New World

windmills used to pump water for farms and ranches,to generate electricity for homes and industry

HOW DOES WIND TURBINES WORK

Wind turbines work on the same principle as ancient windmills : the kinetic energy of the wind rotates the palettes of a propeller with transforms this kinetic energy into electricity by means of a generator.

Wind energy production increased 5 times between 1999 and 2006. At the end of 2006, the worlds capacity of wind generators produced more than 1 % of the global need of electrical energy.

- Zero emission of pollutant substances and gases with greenhouse effect because no combustion takes place

- No waste are produced.

-Reduced costs for the produced energy unit

-reduced costs for their disable

-95% of the land assigned to wind farmscan be also used for other purposes

“visual pollution" – i,.e. unpleasant appearance “nois pollution" (they are noisy).

They affect the medium and the surrounding ecosystems , killing birds and employing huge vacant lands for their installation

Risk of damage from storms, if the wind speeds exceed the limits permitted by design

http://ro.wikipedia.org/wiki/Energie_eolian%C4%83

http://www.energie-eoliana.com/energia-eoliana-notiuni-generale-despre-energia-eoliana/

http://www.eia.doe.gov/kids/energy.cfm?page=about_sources_of_energy-basics

http://www.eia.doe.gov/kids/energy.cfm?page=wind_home-basics