Cogeneration power production in market environment: The impact of the heat storage

The market environment gives to the cogeneration plant a chance to play an active role on the electricity market. Beside heat cogeneration plants can also sell electricity on the organized market. The optimal strategy is highly dependent on the presence of the heat storage which gives an additional flexibility of the heat and power production. We wanted to show the added value of the heat accumulator in making an additional profit with trading electricity on the organized power market. Optimization is based on the mixed integer linear programming considering hot water demand schedule for district heating and industrial steam demand schedule, all technical limitations, and the spot price on the organized electricity market. The criteria function is based on the profit maximization, and as a result a schedule for electricity production is given. We focused on two different cases, with and without heat accumulator in the system. Heat accumulator gives an opportunity to shift the stored heat between intervals, which also reflects in a quantity of produced electricity. The results show a significant impact of the heat accumulator on the flexibility of electricity production which reflects in higher average selling price on the organized electricity market, which means a better economic result for a company.