Evaluation of Different ORC Power Plant Concepts for Geothermal Heat and Power Generation

摘要

In this work, different geothermal heat and power generation concepts are evaluated under techno-economicaspects. The investigated solutions cover different geothermal conditions and ORC power plant technicalfeatures available in Germany. The evaluation is based on annual simulations by using Aspen Plus V8.8. Forthe heat demand, a peak load of 5 MW is assumed. In case of a geothermal well-head temperature of 135 °C,the double-stage ORC shows a second law efficiency of 38.5 %, while the one-stage concept leads to 33.1 %.In general, the analysis shows that the technically more challenging ORC concept leads to a higher amount ofproduced electrical energy and to a lower levelized cost of electricity (LCOE). For instance, the double-stageORC provides a higher turbine power output than the one-stage. In addition, an economic analysis shows thatthe double-stage concept leads to a slightly lower LCOE of 13.79 €ct/kWh compared to the one-stage ORC.The results enable operators and planners to identify the most suitable power plant configuration in dependenceof reservoir conditions and specific heating demand.