ENERGY, COST, AND CARBON-DIOXIDE OPTIMIZATION OF DISAGGREGATED, REGIONAL ENERGY-SUPPLY SYSTEMS

Energy conservation and greenhouse warming mitigation can be supported by cogeneration of heat and power and by heat recovery via heat excha ngers and via the upgrading of environmental and waste heat by heat pu mps. Fuel switching, the use of solar thermal energy, and the removal and disposal of CO, may complement these measures. In order to determi ne the optimum combination of these options with conventional energy-c onversion technologies for regional energy-supply systems with disaggr egated, fluctuating energy-exergy demand profiles, we have developed s tochastic and quasi-dynamic vector-optimization models which can be us ed as computerized planning tools. The application of the stochastic o ptimization model ECCO to a south German model city shows that the pri mary energy input into the system and the CO2 emissions may be reduced by about 25% and 30%, respectively. These figures change as the avera ge ambient temperature deviates from 10 degrees C. The quasi-dynamic o ptimization model ECCO-Solar, applied to an army facility which served as a pilot project with well documented energy and weather data, yiel ds savings of primary energy and CO, emissions which vary between 20% and 50%, depending upon the scenario. Both models show that the optimu m combination of technologies depends very sensitively on the details of the demand situation. Computing the costs and reducing them interac tively, one finds that nearly all of the considered energy conservatio n and emission reduction strategies will become economical only at ene rgy prices which are considerably higher than the present ones.