Development of Green Energy Saving Mechanisms

Abdeen Mustafa Omer
Page No. 37-64

Geothermal energy is the natural heat that exists within the earth and that can be absorbed by
fluids occurring within, or introduced into, the crystal rocks. Although, geographically, this energy
has local concentrations, its distribution globally is widespread. The amount of heat that is,
theoretically, available between the earth’s surface and a depth of 5 km is around 140 x 1024 joules.
Of this, only a fraction (5 x 1021 joules) can be regarded as having economic prospects within the
next five decades, and only about 500 x 1018 joules is likely to be exploited by the year 2020. Three
main techniques used to exploit the heat available are: geothermal aquifers, hot dry rocks and
ground source heat pumps (GSHPs). The GSHPs play a key role in geothermal development in
Central and Northern Europe. With borehole heat exchangers as heat source, they offer de-central
geothermal heating at virtually any location, with great flexibility to meet given demands. In the
vast majority of systems, no space cooling is included, leaving the GSHPs with some economic
constraints. Nevertheless, a promising market development first occurred in Switzerland and
Sweden, and now also is obvious in Austria and Germany. Approximately 20 years of R&D
focusing on borehole heat exchangers resulted in a well-established concept of sustainability for
this technology, as well as in sound design and installation criteria. The market success brought
Switzerland to the third rank worldwide in geothermal direct use. The future prospects are good,
with an increasing range of applications including large systems with thermal energy storage for
heating and cooling, The GSHPs in densely populated development areas, borehole heat
exchangers for cooling of telecommunication equipment, etc. This communication reviews some
interactions between buildings and environment. The correct assessment of climate helps to create
buildings, which are successful in their external environment, while knowledge of sick buildings
helps to avoid unsuccessful internal environments. The sections on energy conservation and green
buildings suggest how the correct design and use of buildings can help to improve total
environment.
Keywords: Green buildings, ground source heat pump, environment