DEVELOPMENT OF VARIOUS LOW-EX SYSTEM COMPONENTS AND THEIR INTEGRATION

The present paper deals with modeling of various low-exergy system components and their integration into the energy system for buildings and small communities. The exergy content of a certain amount of energy is defined as the part of this energy that can be used to produce mechanical energy. The quality of a certain amount of energy is defined as the relative exergy content of this energy. Most of our buildings with their heating and cooling systems today are built for conversion of high quality energy sources to low quality use with a huge destruction of the available exergy as a result. Globally we have a huge potential for transforming our processes to more efficient use of the exergy and also for feeding our processes directly from renewable energy sources without the use of high quality energy sources. To develop our building concepts towards a low exergy building we have to analyze all the processes for energy conversion that take place through the operation of the building, to bring down the needed level of quality for the energy used and then make a holistic analysis of the system. Different processes for energy conversion in buildings are discussed especially giving the potential for saving energy and shifting the energy use to lower quality levels, i.e. in many cases to reduce the temperature levels needed for heating and cooling. The major obstacle for an extensive and effective use of renewabl