Energy left over from the original accretion of the planet andaugm ented by heat from rad ioactive d ecay seeps out slowlyeverywhere, everyd ay. In certain areas the geotherm al grad ient(increase in tem perature with d epth) is high enough to exploit togenerate electricity. This possibility is lim ited to a few locations onEarth and m any technical problem s exist that lim it its utility. Anotherform of geotherm al energy is Earth energy, a result of the heat storagein the Earths surface. Soil everywhere tend s to stay at a relativelyconstant tem perature, the yearly average, and can be used with heatpum ps to heat a build ing in winter and cool a build ing in sum m er. Thisform of energy can lessen the need for other power to m aintaincom fortable tem peratures in build ings, but cannot be used to prod uceelectricity.
WIND Energy from the wind. Why is energy from the wind renewable?
The m ovem ent of the atm osphere isd riven by d ifferences of tem perature at theEarths surface d ue to varyingtem peratures of the Earths surface whenlit by sunlight. Wind energy can be used topum p water or generate electricity, butrequires extensive areal coverage toprod uce significant am ounts of energy.
BIOMASS Energy fromburning organicor living matter. Why is energy from biomass renewable?
BIOMA SS the term for energy from plants. Energy isin this form is very com m only used throughout theworld . U nfortunately the m ost popular is the burningof trees for cooking and warm th. This process releasescopious am ounts of carbon d ioxid e gases into theatm osphere and is a m ajor contributor to unhealthy airin m any areas. Som e of the m ore m od ern form s ofbiom ass energy are m ethane generation andprod uction of alcohol for autom obile fuel and fuelingelectric power plants.
WATER or HYDROELECTRIC Energy from the flow of water. Why is energy of flowing water renewable?
L ike the wind s, flowing water is a prod uct of theearth ´s clim ate and geography. Snowm elt andrunoff from precipitation at higher elevationsflow toward sea level in stream s and rivers. Inan earlier era, water wheels used the power offlowing water to turn grind ing stones and to runm echanical equipm ent. M od ern hyd ro-turbinesuse water power to generate hyd roelectricity.
SUMMARY What are the differences betweennonrenewable and renewable resources?
Renewable resources are those that arereplaced in nature at a rate close to their rateof use. Non renewable resources exist infixed amounts or are used up faster thanthey can be replaced in nature.