Americans used more solar, nuclear, biomass and wind energy in 2008 than they did in 2007, according to the most recent energy flow charts released by the Department of Energy's Lawrence Livermore National Laboratory (LLNL). The nation used less coal and petroleum during the same time frame and only slightly increased its natural-gas consumption. Geothermal energy use remained the same.
The estimated U.S. energy use in 2008 equaled 99.2 quadrillion Btus, down from 101.5 quadrillion Btus in 2007. The increase in wind energy can be attributed to large investments in wind turbine technologies over the last few years, as well as better use of existing turbines, according to the report.
‘This is a good snapshot of what's going on in the country. Some of the year-to year changes in supply and consumption can be traced to factors such as the economy and energy policy,’ says A.J. Simon, an LLNL energy systems analyst.
Distributed electricity represents only electricity sales and does not include self-generation. The Energy Information Administration reports flows from non-thermal resources (i.e., hydro, wind and solar) in Btu-equivalent values by assuming a typical fossil-fuel plant heat rate.
The efficiency of electricity production is calculated as the total retail electricity delivered by the primary energy input into electricity generation. End use efficiency is estimated at 80% for the residential, commercial and industrial sectors, and at 25% for the transportation sector.
Energy use in the industrial and transportation sectors declined by 1.17 quadrillion Btus and 0.9 quadrillion Btus respectively, while commercial and residential use slightly climbed. The drop in transportation and industrial use, which are both heavily dependent on petroleum, can be attributed to a spike in oil prices in summer 2008.
For more information, visit www.publicaffairs.llnl.gov.
SOURCE: Lawrence Livermore National Laboratory