|
Electricity
 |
- Click image to enlarge
- Data source: US Energy Information Administration
Link to chart data |
Power plants that burn fossil fuels to generate electric energy are major contributors to global warming. Your utility charges you for the electric energy you use. But in addition to energy considerations, there must be adequate energy being generated at any moment to “keep the lights on,” that is, to provide all the energy required. Generating capacity determines the rate at which the electricity grid can provide energy and must always be precisely balanced with consumption. Variable energy resources like wind and solar are sometimes denigrated because they cannot be relied on at all times to provide the needed generating capacity. It is foolish, however, to ignore the energy that these non-polluting resources can provide. Energy and capacity are both essential features of the electricity system.
For further details, visit the Energy vs. Capacity page. |
Electric Energy Resources
Almost any source of energy can be used to generate electricity. Because of its low cost, about half of all the US electric energy comes from coal. Natural gas is also a widely used power plant fuel. Coal, gas and nuclear combined provide over 90% of US electric energy, and hydroelectricity contributes most of the rest. Less than 1% of US electric energy comes from solar, wind, geothermal and other renewable resources. Most good sources of hydroelectricity in the US have already been developed. The future of nuclear power is murky until the waste storage problem is solved. To limit global warming, the US and other countries must rapidly develop these renewable energy resources.
|
|
California is blessed with ample renewable energy resources with which to generate electricity. Potential for solar power is almost unlimited. Wind and geothermal resources are abundant. Large scale development of these resources occurred in the 1980s but has stagnated since then. Nevertheless, about 10% of California’s electric energy comes from wind, geothermal and solar resources, more than any other state. In recent years, however, electricity from natural gas has increased rapidly, and the state also imports substantial amounts of coal-fired power from neighboring states.
Visit California’s Electric Energy Options page for a complete description of how the state can meet its global warming goals in the electricity sector. |
|
Conventional power plants combine fuel with oxygen from the air in a combustion process. Fuel cells, however, combine hydrogen with oxygen at lower temperatures to generate electricity without combustion. The waste product from a fuel cell is pure water, avoiding the pollution from a conventional power plant. Unfortunately, hydrogen does not occur naturally. Most fuel cells in operation today obtain their hydrogen from natural gas. In the splitting process, the carbon in natural gas combines with oxygen to form carbon dioxide, the major greenhouse gas, so fuel cells that obtain hydrogen from natural gas also contribute to global warming. Nevertheless, fuel cells can operate at quite high energy efficiencies and have a place in the future electricity system.
Visit the Fuel Cell page for further information. |
|
For a variety of reasons, power plants are often not located in cities where electricity is needed. For example, renewable energy resources are located where Mother Nature puts them, often far from where people live. To move electric energy from generators to consumers, transmission lines (power lines) are needed. Transmission lines are operated at high voltages in order to carry more power with smaller wires, but understandably, no one wants high-voltage transmission lines in their back yard. However, new transmission lines are essential to modernize the electricity system and deliver clean power to consumers. CEERT experts are helping California plan new transmission lines to access renewable energy resources.
For details, visit the Transmission page. |
|
