Illinois has been emitting less carbon dioxide (CO2) per unit of energy used since 1960, and CO2 generation is expected to remain fairly stable to the year 2000. This has some relevance to atmospheric quality, and thus to human health; the rate at which the atmosphere is loaded with carbon dioxide also is affected.
Those trends reflect relative declines in the use of fossil fuels for electricity generation. The efficiency with which fossil fuels are used also determines how much fossil fuel is consumed. Energy efficiency has improved in Illinois through the 1980s as it has in the rest of the U.S. This trend reverses a marked pattern of higher energy consumption evident since the 1960s. The result has been significant energy economies and cleaner air in spite of substantial increases in vehicle miles traveled. Smaller efficiency gains in buildings and houses should continue as well, although trends in all cases are contingent upon energy prices and government regulation.
Source: Earth Resources, Illinois State Geological Survey, 1994
Overall, energy efficiency improved in Illinois by some 46% from 1963 to 1990. These gains were achieved in spite of the fact that "heat rates," or the amount of energy needed to generate a kilowatt of electricity, have decreased by only 10% since the 1960s. Currently, about two-thirds of the energy input at a fossil-fuel-fired electricity generating plant is lost due to inherent inefficiencies in the technology. That means that about one-quarter of all Illinois energy consumption is accounted for by largely unavoidable losses from electricity generation.
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