Primary energy, consumption sectors

Transportation accounts for about one-fourth of the primary energy consumption in the United States. And unlike other sectors of the economy that can easily switch to cleaner natural gas or electricity, automobiles, trucks, nonroad vehicles, and buses are powered by internal-combustion engines burning petroleum products that produce carbon dioxide, carbon monoxide, nitrogen oxides, and hydrocarbons. Efforts are under way to accelerate the introduction of electric, fuel-cell, and hybrid (electric and fuel) vehicles to replace sonic of these vehicles in both the retail marketplace and in commercial, government, public transit, and private fleets. These vehicles dramatically reduce harmful pollutants and reduce carbon dioxide emissions by as much as 50 percent or more compared to gasoline-powered vehicles. 

Figure 6 United States primary energy consumption by source and sector - 2007...

U.S. primary energy consumption, by sector, historical and projected, 1970 to 2025,... 

Carbon intensity of global primary energy consumption, 1890 to 1995, 14 2-6 Trends and projections in U.S. carbon emissions, by sector and by fuel, 1990 to 2025, 15... 

More than half of the world primary energy consumption is used as hot water, steam and space heat. Unlike fossil energy carriers, nuclear power is almost exclusively used for commercial electricity production. Clearly nuclear heat production could play a major and important role in the non-electric sector. Nuclear growth depends on the future public perception of the comparative benefits, cost, and risks of alternatives. Based on the comparative evaluation of tangible risks to public health, safety, and environment, nuclear power appears to be a better choice than fossil fuels. 

Presently, the availability of great amounts of fissile plutonium produced by thermal reactors and that released from now-redundant nuclear weapons in the USA, the Russian Federation, the European Union, and in some other countries with significant nuclear power sector and relatively slow primary energy consumption growth, has eliminated the initial requirements of short doubling time and high breeding ratio. 

Recognizing these data constraints, it seems that biomass contributes about one-third of the primary energy consumption in developing coimtries but varies from over 90% in less developed countries such as Uganda, Rwanda, Tanzania, and Nepal to about 45% in India, 30% in China and Brazil, and 10-15% in Mexico and South Africa. By comparison, the share of primary energy provided by biomass within industrialized countries is estimated to be only about 3%. Importantly, however, the absolute consumption per capita varies by a much smaller amount worldwide. Indeed, cross-sectional studies seem to indicate that economic development does not usually result in less overall absolute use of biomass fuel, although its fraction of total energy declines and use shifts from households to other sectors. Overall, current commercial and noncommercial biomass fuel supplies about 20-60 EJ/y worldwide. Recent lEA estimations, for example, indicate approximately 40 EJ/y (Table II). 

U.S. Energy Information Administration (2008) Primary energy consumption by source and sector. Annual Energy Review, http //www.eia.doe.gov/aer/pecss diagram.html. Accessed 1 June 2010... 

From 1996 to 2000, the natural gas consumption in Italy grew from around 56.2 billion cubic metres to 70.4 billion, a rise that derived primarily from growth in the power generation sector, in which consumption doubled. In the same period, natural gas was the primary energy source that grew most rapidly, increasing at an average annual rate of 5.8%. 

Demand for primary energy carriers cannot be measured but must Ije calculated on the basis of, for example, final energy consumption and knowledge of fiows in the energy sector itself. The simplest approach used is that of adding sectoral fuel consmnption to the electricity consumption using a conversion efficiency for electric power plants. More sophisticated methods also take into account the losses in production, conversion, and transportation of the fuels. Whether to use uniform conversion, factors for all countries and for different points in time or country-dependent and time-dependent factors depends on the goal of the analysis. 

Several important generalizations can be made. The first is that fossil fuel prices are primary competition for biomass energy. Table 28 summarizes 1990 U.S. tabulations of average, consumption-weighted, deflvered fossil fuel prices by end-use sector (90). The deflvered price of a given fossil fuel is not the same to each end user ie, the residential sector normally pays more for fuels than the other sectors, and large end users pay less. 

Table 1 is an estimate of energy usage by United States industry for 1988 (1). The chemical industry used 21% of the energy consumed by the U.S. industrial sector, and the other three related process industries, paper (qv), petroleum (qv), and primary metals, combined for an additional 50% of the industrial consumption. 

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