Chapter 8 - Geothermal district energy systems

Abstract

There are commonly three major commodities—electricity, heating, and cooling—that communities need and that rely heavily on fossil fuels, such as coal, petroleum products, and natural gas. Thus there is a strong need for such communities to have a better environment and more sustainable development. In this regard, geothermal energy is well-known as an effective method for hot water preparation and space heating in residential buildings, and, today, novel district heating plants can supply cities or small communities. The most important feature is the utilization of a power resource that offers an important cost differential in producing thermal energy compared with classic heating systems utilizing boilers or direct electrical energy heating. Geothermal energy–based district systems have great potential and an important role in meeting energy needs depending on developing technology. Renewable energy–based systems are increasing in popularity in terms of meeting both environmental policies and sustainability. Regions rich in geothermal energy resources can achieve significant gains in terms of both regional development and sustainability by using these energy resources in region-energy systems. In this chapter, first, geothermal energy–based regional energy systems are described. Then the advantages of these systems are discussed comprehensively for the community, and consumer. Also, geothermal energy–based district energy systems are evaluated in five sections: district heating plants, district cooling plants, combined district heating and cooling plants, cogeneration-based district energy plants, and integrated district energy plants. A case study has been given for each energy system. Thermodynamic and performance analyses of these systems have been carried out with these case studies. Performance curves of these systems are given comparatively in the graphs, depending on various system indicators.