Unit 3: Energy Resources

Alcohol

Liquid fuels can also be derived from biomass . For example, ethanol , an alcohol, can be made by fermenting fruit or agricultural waste. In the United States, corn is a major source of ethanol. Cars and trucks can run on ethanol or gasohol, a blend of gasoline and ethanol. Gasohol produces less air pollution than fossil fuels. Some states require the use of gasohol in vehicles as a way to reduce air pollution .

Petroleum (Crude Oil)

A liquid mixture of complex hydrocarbon compounds Used widely as a fuel source . A petroleum product is anything that is made from crude oil, such as fuels, chemicals, and plastics. Uses of petroleum include: - 88% is burned or used as fuel - 3% manufacturing - accounts for 45% of the world's commercial energy use.

Non-Renewable Resources

A nonrenewable resource is a natural substance that is not replenished with the speed at which it is consumed.It is a finite (limited) resource.Fossil Fuels such as oil, natural gas, and coal are examples of nonrenewable resources.

Coal

Formed from remains of plants that lived in swamps hundreds of millions of years ago. As ocean levels rose and fell, swamps were covered with sediment . Layers of sediment compressed the plant remains, Heat and pressure within the Earth's crust caused coal to form.

Methane

when bacteria decompose organic wastes, one byproduct is methane gas. Methane can be burned to generate heat or electricity. In China, more than 6 million households use biogas digesters to ferment manure and produce gas for heating and cooking. Some landfills in the United States generate electricity by using the methane from the decomposition of trash .

Types of renewable energy include

solar energy, wind energy , Hydroelectric (the power of moving water, Geothermal (Earth's heat)

Fossil Fuels

A fossil fuel is: nonrenewable energy resource formed from the remains of organisms that lived long ago Examples include oil, coal, and natural gas. Used to run cars, ships, planes, and factories and to produce electricity.

Oil and Natural Gas

Oil and natural gas result from the decay of tiny marine organisms that accumulated on the bottom of the ocean millions of years ago. Buried by sediments heated until they became complex energy-rich hydrocarbons Migrated into the porous rock formations that now contain them.

Future of Nuclear Power

One possible future energy source is nuclear fusion . This is the combination of the nuclei of small atoms to form a larger nucleus. Nuclear Fusion: - releases tremendous amounts of energy. - potentially a safer energy source than nuclear fission is because it creates less dangerous radioactive byproducts.

Geothermal power plants generate electricity using the following steps:

1. Steam rises through a well 2.Steam drives turbines, which generate electricity 3. Leftover liquid is pumped back into the hot rock 4. The leftover liquid, water, is returned to Earth's crust because it can be reheated by geothermal energy and used again.More than 600,000 homes in the United States are heated and cooled using geothermal heat pumps . A geothermal heat pump uses stable underground temperatures to warm and cool homes because the temperature of the ground is nearly constant year-round. A heat pump is simply a loop of piping that circulates a fluid underground .

Advantages of Nuclear Energy

A very concentrated energy source. Do not produce air-polluting gases. Release less radioactivity than coal-fired power plants do, when operated properly.

Photovoltaic cells

Are solar cells that convert the sun's energy into electricity. Solar cells have no moving parts, and they run on non-polluting power from the sun. However, they produce a very small electrical current.Meeting the electricity needs of a small city would require covering hundreds of acres with solar panels.Solar cells require extended periods of sunshine to produce electricity. This energy is stored in batteries , which supplies electricity when the sun is not shining.Currently, solar cells provide energy for more than 1 million households in developing countries, where energy consumption is minimal and electricity distribution networks are limited.

Biomass/Biofuels

Biomass fuel consists of plant material, manure, or any other organic matter that is used as an energy source. Fossil fuels can be thought of as biomass energy sources, although they are nonrenewable. Renewable biomass fuels, such as wood and dung, are major sources of energy in developing countries.More than half of all wood cut in the world is used as fuel for heating and cooking.Although materials like wood are a renewable resource, if trees are cut down faster than they grow, the resulting habitat loss, deforestation, and soil erosion can be severe . In addition, harmful air pollution may result from burning wood and dung.

Disadvantages of Nuclear Energy

Difficulty in finding a safe place to store nuclear waste. Can remain dangerously radioactive for thousands of years .Building and maintaining a safe reactor is very expensive In a poorly designed nuclear plant, the fission process can potentially get out of control.

Wind Energy

Energy from the sun warms the Earth's surface unevenly, which causes air masses to flow in the atmosphere.We experience the movement of these air masses as wind . Wind power, which converts the movement of wind into electric energy , is the fastest growing energy source in the world.Wind turbines are used to capture the energy from the wind. Large arrays of wind turbines are called wind farms . Large wind farms supply electricity to thousands of homes. In windy rural areas, small wind farms with 20 or fewer turbines are also becoming common. Because wind turbines take up little space, some farmers can add wind turbines to their land and still use the land for other purposes.

Water/Hydroelectric/Tidal

Hydroelectric energy is electrical energy produced by falling water .Hydroelectric energy accounts for 20% of the world's electricity.Large hydroelectric power plants have a dam that is built across a river to hold back a reservoir of water The water in the reservoir is released to turn a turbine , which generate electricity .

Geothermal Energy

In some areas, deposits of water in the Earth's crust are heated by geothermal energy. Geothermal energy is the energy produced by heat within the Earth. The United States is the world's largest producer of geothermal energy. Although geothermal energy is considered a renewable resource, the water that is used must be managed carefully so that it is not depleted.

Solar Energy

Nearly all renewable energy comes directly or indirectly from the Sun. Direct solar energy is used every day, such as when the sun shines on a window and heats the room.Solar energy can also be used indirectly to generate electricity in solar cells.Active solar heating is the gathering of solar energy by collectors that are then used to heat water or heat a building.More than 1 million homes in the United States use active solar energy to heat water. Solar collectors , usually mounted on a roof, capture the sun's energy.

Nuclear Energy

Nuclear energy originates from the splitting of uranium atoms - a process called fission . This generates heat to produce steam, which is used by a turbine generator to generate electricity .

Renewable Energy

Renewable energy is energy from sources that are constantly being formed.