Impact of Heat Storage Capacity on CHP Unit Commitment Under Power Price Uncertainties

Combined heat and power (CHP) plants generate heat and power simultaneously leading to a higher efficiency than an isolated production. CHP unit commitment requires a complex operation planning, since power is consumed in the moment of generation. The integration of a heat storage allows a partially power price oriented plant operation, where power is generated especially in times of high market prices. Consequently, an efficient plant operation depends on the accuracy of the anticipated power prices and the flexibility due to storage capacity. This contribution analyzes the effects of short-term uncertainties in power prices on the CHP unit commitment for different heat storage capacities. A simulation study is run to evaluate the financial impact of an inaccurate power price anticipation. Results show that the storage capacity affects the sensitivity of the solution due to stochastic influences. The isolated consideration of long-term uncertainties might result in a suboptimal choice of heat storage capacity. It is recommended, to explicitly consider short-term uncertainties when supporting strategic planning of heat storage capacities.