Energy sources fossil fuels

Each society s choice of energy sources depends on a range of factors such as availability, convenience, price, nature of the risk, and more recently, potential environmental impact. No energy source, not even solar or wind, is benign from an environmental perspective, as each step in the energy life cycle—exploration, production, transportation, conversion, and end use—has environmental effects associated with it. Therefore, in order to estimate the environmental impacts of a particular energy source (fossil fuel, nuclear, renewables, etc.), it is essential to analyze the impacts from all parts of the full life cycle. 

Estimate emissions of greenhouse gases (CO2, CH4, and N2O) and criteria pollutants [VOCs, CO, NOx, PMjo (particulate matter with diameter less than 10 microns), and SOx] and energy use for all energy sources, fossil fuels (petroleum, natural gas, and coal), and petroleum. 

A transition from convenient but environmentally not so friendly, and ultimately scarce energy sources (fossil fuels) to less convenient, but clean and nonexhaustable ones (renewable energy sources) seems to be imminent. Hydrogen may play a significant role in this transition by allowing renewable energy sources to be used in virtually any application. 

Hydrogen can be generated from a variety of sources fossil fuels such as natural gas, naphtha, fuel oils, coal renewable fuels such as landfill gas and water by electrolysis. Generating hydrogen from fossil fuels is viewed as a transitional strategy on the pathway to an environmentally responsible, sustainable energy economy (DOE, 1998). 

Economic and social research on the factors which will determine future emissions of carbon dioxide. This should include the probable rise of future rates of world energy use and the future misuse of energy sources — that is, the ratio of energy from fossil fuel combustion to that from other energy sources. Also needed are better estimates of possible future changes in the areas of forests. 

The very existence of our technological society depends on an abundant supply of energy. Although the United States has only 5 percent of the world s population, we consume about 20 percent of the world s energyl At present, the two major sources of energy are fossil fuels and nuclear fission (discussed in Chapters 23 and 24, respectively). Coal, oil (which is also known as petroleum), and natural gas (mostly methane) are collectively called fossil fuels because they are the end result of the decomposition of plants and animals over tens or hundreds of millions of years. 

In Fig. 2.17 the flow of solar radiation as well as other energy sources for utilizing in different forms of energy is represented. It is remarkable that nearly all solar and atmospheric energy is dissipated into heat and IR radiation, finally back to space - the efficiency for usable energy is small (concerns NPP 2 10 % related to solar absorption). The amount of energy in fossil fuels (still available 5.5 10 J) is only one-hundredth of the yearly incoming solar flux, but was buried 50-100 Myr ago and over a period of millions of years. 

---