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, ____________