Monday, May 10, 2010

US Energy Sources and Demand by Sector

Where does the U. S. gets its energy?

85% from fossil fuels:
39% from petroleum
23% from natural gas
23% from coal

8% from nuclear fission - all used for electricity

3% from biomass - mostly used for fuel
3% from hydro - mostly used for electricity

1% from geothermal, wind and solar total

What happens to this energy?

55% is utilized:
41% used directly as fuel for vehicles, as feedstocks for industrial products, and heat sources for buildings
14% as electricity output from power plants

45% is lost as "waste heat"
27% lost in conversion from chemical to electrical energy
18% lost in conversion from chemical energy to mechanical energy

What is this energy used for?

31% used by industry
29% used for transportation
21% residential uses, such as heating, cooling and lighting
18% commercial uses, such as heating, cooling and lighting

Source: MIT Technology Review, May/June 2010.

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