High Temperature Seasonal BTES for Effective Load Shifting and CO2 Emission Reduction
Abstract
A BTES storage shall be built on the Empa campus. It will be used to store waste heat in summer and provide an energy source for heat pumping in winter. Instead of the currently planned low temperature BTES, a high temperature BTES with a radial temperature gradient shall be investigated with charging from the center and discharging from the outer ring. The aim is to realize an effective seasonal load shifting and a reduction of the yearly CO2 emission through optimizing for high COPs of the heat pump operation in winter. With the help of TRNSYS, different cases with variation of the operational temperature as well as geometrical and hydraulic parameters were simulated. The electrical consumption assigned to the operation of the BTES was converted into CO2 emissions with the help of dynamic CO2 emission data available for Switzerland. The results show that with the physical limitations given on the Empa campus and the simplified sampling of the CO2 data used performance expectations could not be confirmed and a consequent implementation of a high temperature BTES on Empa campus will not be realized.