Energy and Exergy Analysis of Systems for Electrical Energy Production and Heating Purposes at Various Temperatures

Cogeneration, i.e. the combined production of electrical and thermal power at an energy conversion plant, has received significant attention particularly since the oil crises of the 70s. The idea of cogeneration is attractive due to the very low exergy efficiency of traditional separate heating plants, using every kind of fuel.

The aim of this paper is to compare the usual energy analysis with a meaningful exergy analysis of a combined thermal and electrical power plant. The above exergy analysis is also the basis for a proper allotment of costs between electrical and thermal energy at various temperatures.