There are several alternative fuels and other technologies available for vehicles today that will decrease our dependency on oil and decrease the amount of pollutant emissions.
|Vehicle alternative fuels||Vehicle alternative fuels||Other technologies|
|Compressed Natural Gas (CNG)||Biodiesel||Hybrid (gasoline-electric)|
|Liquefied Natural Gas (LNG)||Ethanol||Electric cars|
|Propane or Liquefied Petroleum Gas (LPG)||Methanol|
There are several energy sources that can off-set the U.S. dependency on fossil fuels for generation of electricity, including:
Hydrogen's potential use in fuel and energy applications includes powering vehicles, running turbines or fuel cells to produce electricity, and generating heat and electricity for buildings. Hydrogen is high in energy, yet produces almost no pollution. NASA has used liquid hydrogen since the 1970s to propel the space shuttle and other rockets into orbit, producing pure water as a byproduct.
Hydrogen fuel cells are considered a promising technology for use as a source of heat and electricity in buildings, and as an electrical power source for electric vehicles.
Solar energy is absorbed by collector cells or photovoltaic (PV) cells that convert sunlight to electricity.
Advantages - It is relatively pollution free, low maintenance, and increasing efficiency.
Disadvantages - It is only available in abundance near the tropics which are relatively cloud free and remote from the places of highest energy demand, and of course not available at night. Solar cell technologies produce DC power which must be converted to the AC power for use in distribution grids, and must be converted into some other form of energy for storage.
Wind power refers to the extraction of useful energy from the wind by converting the rotation of turbine blades into electrical current by means of an electrical generator. In 2005, worldwide capacity of wind-powered generators was less than 1% of electricity use, however utilizing wind as an energy source is increasing in many areas of the world. U.S. energy studies have concluded that wind harvested in just three of the 50 states could potentially provide enough electricity to power the entire country.
A drawback of using wind power is the issue of intermittent availability. Analysis of energy production shows that half of the energy produced by a turbine is generated in just 15% of the operating time of a turbine. The consequence is that wind energy additional output cannot be supplied in response to load demand.
Geothermal heat can be used to generate electricity. Geothermal power is often referred to as a form of renewable energy, but because the heat at any location can eventually be depleted it is not technically considered renewable. Geothermal power is generated by mining the earth's heat. In areas with high temperature ground water at shallow depths (Iceland), wells are drilled into natural fractures in basement rock or into permeable sedimentary rocks. Hot water or steam flows up through the wells either by pumping or through boiling (flashing) flow.
Hydropower is energy obtained from flowing water. Energy in water can be harnessed and used for this usefulness, in the form of motive energy or temperature differences. The most common application is the dam, but it can be used directly as a mechanical force or a thermal source/sink.
hydroelectric power is probably not a major option for the future of energy production in the developed nations because most major sites within these nations with the potential for harnessing gravity in this way are either already being exploited or are unavailable for other reasons such as environmental considerations.
Uranium, a nonrenewable resource is extracted from mines. Once mined, the uranium ore is processed to create enriched fuel for use in a nuclear power plant. At the power plant, the uranium is bombarded with neutrons, causing the uranium atoms to split (fission) and release both heat and neutrons. These neutrons collide with other uranium atoms and to release additional heat and neutrons in a chain reaction. This heat is used to generate steam, which is used by a turbine to generate electricity.
EPA Fuel Economy Program (PDF)
EPA Fuel Options for Trucks and Buses (PDF)