Fossil primary energy sources

Fossil primary energy sources Renewable primary energy sources... 

In conventional boilers nearly 100 % of the primary energy is converted to heat used in the households to heat up the rooms or to provide warm water. Natural gas and heating oil are today the dominant primary energy sources in the building sector. Over 17 million households in Germany use fossil primary energy sources in decentralized boilers. Centralized power plant supplies the needed electrical power to households via the European distribution network. 

All fossil primary energy sources (from natural gas all the way to uranium) are limited in availability [7]. Their more efficient use will not automatically lead to a sustainable energy supply system since depletion will simply occur later but not be totally avoided. Nevertheless, increased energy efficiency buys time to further develop sustainable energy supply technologies, based on renewable energies. As will be shown later, SOFC technology is specifically helpful in such a transition phase since it can use both fossil- and renewables-based fuels. 

The transition from nonrenewable fossil fuel should consider the development of technologies that can use the available energy of the sun. It is reasonable to assume that solar energy will eventually serve as a primary energy source. As we attempt to use solar energy to replace the use of fossil and nuclear fuels, this relationship between solar energy and hydrogen returns and one may not effectively work without the other. 

The natural gas sources are spread unevenly over the world with almost 70% of the natural gas reserves located in the Middle East, Russia and the Caucasus region as shown on Figure 4. Provided the consumption of primary energy sources is maintained at present level the depletion time is reportedly 60.7 years for natural gas according to BP [3] (40.6 years for oil, and 204 years for coal)1. Although these estimates do not reflect the real source, they confirm that the fossil resources are rather limited and may be depleted within a few generations. 

Diversity of purveyors, transport system and also diversity of sources contribute significantly to security of energy supply and less dependence on monopoly distributor of fossil fuels and primary energy sources can significantly help economical prosperity of regions without own sources, e.g. South Caucasus, Balkans, Central and East Europe. It also helps to avoid different commercial and/or political pressure on the final consumer. From this reason a possibility of using different ways of fossil fuels transport will be discussed. 

At the consumer end, about one-quarter of the primary energy is used as electricity and three-quarters as fuel. The above mentioned primary energy sources must therefore by converted to these energy carriers needed by the consumer. In contrast with the fossil fuels, none of the new primary energy sources can be directly used as a fuel, e.g., for air transportation, land transportation. Consequently, they must be used to manufacture a fuel or fuels, as well as to generate electricity. 

Hydrogen can be produced, in theory, from a variety of sources including primary energy sources and water. In the absence of significant technological breakthroughs in renewable electricity production or unconventional hydrogen-production techniques, natural gas and other fossil fuels will likely continue to be used to create the vast majority of hydro-... 

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