Renewable Energy Resources
two thirds
As much as ___________ of what is thrown away could be burned
magma
Bodies of_______ can heat large reservoirs of groundwater.
problems with using energy from garbage
Burning waste can produce toxic ash residue and air pollution.
geothermal energy
Energy obtained by using hot magma or hot, dry rocks inside Earth.
renewable energy resources
Energy resources that can be replaced in nature or by humans within a relatively short period of time... generally defined as, being within a human life span... example... trees
gasohol
Ethanol then can be mixed with another fuel (gasoline) to create _____________
garbage
Every day humans throw away a tremendous amount of burnable ___________
Problems with burning wood
Gases and small particles are released during combustion... materials can pollute the air... during harvest of trees natural habitats are destroyed.
wood
Much of the world still cooks with _______. In fact, ________ is used more widely today than any other type of biomass fuel.
active solar
Solar cells collect energy from the Sun and transform it into electricity... Solar cells were invented to generate electricity for satellites.
Disadvantages of Solar Energy
Solar cells work less efficiently on cloudy days and cannot work at all at night...
passive solar
South-facing windows on buildings act as heat collectors, warming exposed rooms.
Fluid biomass fuels
_______ are more efficient and have more uses than solid biomass fuels do
Gasohol
can be used in the same way as gasoline... but it cuts down on the amount of fossil fuel needed to produce gasoline.
Benefits with burning garbage
decrease human dependence on fossil fuels... is a cheap source of energy .... helps reduce the amount of material that must be dumped into landfills
hydroelectric energy
electricity produced by waterpower
Biomass energy
energy derived from burning organic material such as wood, alcohol, and garbage.
Solar energy
energy from the Sun
Advantage of solar energy
is clean and inexhaustible
Advantages of wind energy
is nonpolluting and free ... It does little harm to the environment and produces no waste.
biomass materials
major renewable energy resource
Disadvantages of wind energy
only a few regions of the world have winds strong enough to generate electricity... wind isn't steady... Sometimes it blows too hard and at other times it is too weak or stops entirely
Geothermal energy
presently is being used in Hawaii and in parts of the western United States.
distillation
process in which plant material is turned into burnable fuel... for example, biomass fuels, such as corn, are changed to an alcohol such as ethanol
microhydropower
process used throughout the world in which a waterwheel is used to do work
passive or active
solar energy can be ________________
inexhaustible energy resources
sources of renewable energy that are constant and will not run out in-the future... includes the Sun, wind, water, and geothermal energy
conservation methods
tree farms are maintained specifically for use as fuel, energy from wood can be a part of future energy resources.
problems with hydroelectric
upstream lakes fill with sediment and downstream erosion increases... Land above the dam is flooded... wildlife habitats are damaged.
Geothermal power plants
use steam from the reservoirs of hot water near sources of magma to produce electricity
Wind energy
used to power sailing ships ... drive windmills ... turns wind turbines
wind farm
when a large number of windmills are placed in one area for the purpose of generating electricity
solar energy is used indirectly
when the wind and some types of moving water are used to do work, ____________
