Fossil resources, current dependence

The increasingly volatile prices and availability of gasoline and natural gas has brought about a heightened awareness of our dependence on nonrenewable resources. Currently, over 90% of the US electricity supply comes from the combustion of fossil fuels i.e., coal, oil, and natural gas) and nuclear power generation. 

Woody plants, coal, petroleum, and natural gas provide a vast resource of energy that originally came from the sun. By the process of photosynthesis, plants store energy that can be claimed by burning the plants themselves or the decay products that have been converted to fossil fuels. Although the United States currently depends heavily on petroleum for energy, this dependency is a relatively recent phenomenon, as shown in Fig. 9.13. In this section we discuss some sources of energy and their effects on the environment. 

Although the production of biofuels is of considerable economic relevance, it is also characterized by heated political, ecological, and social debates. Recombinant technologies and second-generation fuels are expected to contribute to a reduction in the dependence on fossil resources and to significantly reduce greenhouse gas emissions ([73], section 12.2). A calculation of emissions yielded 94 for gasoline, 77 for currently available bioethanol, and 11 for cellulosic-based ethanol... 

Current commercial processes for syngas and H2 production largely depends on fossil fuels both as the source of hydrogen and as the source of energy for the production processing.4 Fossil fuels are nonrenewable energy resources, but they provide a more economical path to hydrogen production in the near term (next 5-20 years) and perhaps they will continue to play an important role in the midterm (20-50 years from now). Alternative processes need to be developed that do not... 

While current energy consumption depends primarily on fossil fuels, the world cannot rely on them forever. We eventually will be constrained by resources. Reserve estimates and corresponding reserve-to-production (R P) ratios, defined as the number of years reserves will last at current production levels, are summarized in Table 1.1. 

Due to the current low costs of natural uranium and uranium enrichment, the use of uranium dioxide fuel with postponed reprocessing and spent fuel storage on the nuclear power plant site, are economically preferable for SVBR-75/100 at the moment. The duration of the benefits of this fuel cycle option depends on the available uranium resources and nuclear power deployment scale. In any case, the existing uranium resources are sufficient to achieve the realistic scenario of nuclear power development until the year 2050. The costs of natural gas could be expected to increase more intensively than the costs of natural uranium. This will ensure the NPP competitiveness even with a considerable increase in uranium prices, because the structure of electricity cost is different for NPPs and fossil-fuelled heat power plants. 

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