Optimal Coordination of CHP Plants with Renewable Energy Generation Considering Substitutability between Electricity and Heat

Combined heat and power (CHP) plants have experienced rapid development in recent years for achieving high energy efficiency. Moreover with the increasing penetration of renewable energy generation (REG), CHP plants have responsibility for providing flexible services in accommodating REG. With the development of electric heating, the extent of utilizing electricity for substituting conventional heat provided by district heating (DH) is studied. The possibility of encouraging consumers selecting different kinds of energy forms for space heating in response to particular conditions within the electricity system is analyzed. Being able to transform heating demand to electrical demand removes the heat production restriction of CHP plants and achieves the flexible operation of CHP plants for satisfying large-scale renewable energy integration. The optimization model for dispatching CHP plants to minimize overall cost while satisfying the end-users need is developed. Simulation result shows that the proposed technique can smooth the variations in net load -decreasing peak-valley ratio by 38%. And 5% operation cost can also be saved due to the overall optimization of the integrated energy system.