Low-Carbon Dispatch of Integrated Energy Systems Considering Solar Thermal Coupled Combined Heat and Power Units

Abstract

To reduce carbon emissions of an integrated energy system (IES), and decrease curtailment of wind and solar energy due to the “power determined by heat” characteristics of combined heat and power (CHP) units, this paper proposes a low-carbon and economic optimal scheduling model of an IES that considers solar thermal coupled with CHP. First, to alleviate the coupling of heat and electric power, a solar thermal collector (STC)-CHP unit model is developed by integrating an STC unit with the traditional CHP unit in the IES. In addition, hydrogen energy utilization equipment, including hydrogen fuel cell (HFC), hydrogen storage (HS), is introduced based on the traditional power-to-gas (P2G) process, to fully exploit the value of hydrogen. Meanwhile, the carbon capture system (CCS) is considered in the IES to reduce the carbon emission. Next, a low-carbon economic dispatch model of the STC-CHP-P2G-CCS coupled IES is established considering the reward and punishment ladder-type carbon trading (RPLCT) mechanism, aiming to minimize economic costs. The proposed model is solved by programming the CPLEX solver through the YALMIP toolbox. Finally, two categories of scenarios simulation are set up to evaluate the proposed IES and its dispatch strategy. Results show that the total daily operating cost of the proposed system amounts to 8.6525 million RMB, marking a significant reduction of 8.2695 million RMB compared to the basic system. This substantial saving not only covers but also exceeds the daily investment cost of 1.8561 million RMB required for the new equipment, demonstrating a certain level of economic viability. In addition, the system achieves a 100% renewable energy accommodation rate, and carbon emissions are reduced by 2596.3 tons by incorporating the RPLCT mechanism, achieving negative carbon emissions.