Renewable Energy Flashcards
(31 cards)
How much renewable energy supplies the U.S.
8%
How much renewable energy supplies the world?
18%
Where is renewable energy derived from?
Sun’s energy
What is Biomass?
organic plant matter produced by photosynthesis; bioenergy is obtained from it
How much of Biomass supplies the US
50%
How much of Biomass supplies the world?
80%
Biopower generates electricity from what sources? (2)
1) waste products
2) bioenergy crops
How can bio mass be used in vehicles
ethanol for gas
What are some problems with biofuels?
1) growing corn for ethanol causes negative impacts on environment
2) growing corn for ethanol requires large amounts of fossil fuels
3) not energy efficient
How much solar energy is supplied to the U.S?
15%
How much had solar grown annually world wide in the last 40 years?
30%
Active Solar system
specially designed collected that concentrate solar energy and store it as heat for space and/or water heating
Photovoltaic solar cells?
converts solar radiation directly into electricity
What are thin-film solar cells?
Photovoltaic materials compressed into ultra thin sheets
benefits of solar energy? (6)
1) inexhaustible source
2) uses no fuel, so no air pollution
3) safe
4) little maintenence
5) does not need to be near a power plant
6) creates green jobs
Disadvantages of Solar energy (3)
1) not all regions are sunny
2) storage required
3) high costs
What were windmills first used for?
first used in 1600’s to pump water and grind grain
What are windmills now used for?
to generate electricity for farms beyond utility poles
True or false; Today wind energy is the cheapest form of alternative energy
True
How much wind energy could supply the U.S. by 2030?
1/5
Where is Geo thermal energy from?
from heat of earth’s interior
Geo-thermal energy: Dry Steam
Steam with no water droplets
Geo-thermal energy: Wet Steam
a mixture of steam and water droplets
Geo-thermal energy: Hot dry rock
molten rock penetrates the earth’s crust and heats the subsurface rocks
