Operational Planning and Bidding for District Heating Systems with Uncertain Renewable Energy Production

Abstract

In countries with an extended use of district heating (DH), the integrated operation of DH and power systems can increase the flexibility of the power system achieving a higher integration of renewable energy sources (RES). DH operators can not only provide flexibility to the power system by acting on the electricity market, but also profit from the situation to lower the overall system cost. However, the operational planning and bidding includes several uncertain components at the time of planning: electricity prices as well as heat and power production from RES. In this publication, we propose a planning method that supports DH operators by scheduling the production and creating bids for the day-ahead and balancing electricity markets. The method is based on stochastic programming and extends bidding strategies for virtual power plants to the DH application. The uncertain factors are considered explicitly through scenario generation. We apply our solution approach to a real case study in Denmark and perform an extensive analysis of the production and trading behaviour of the DH system. The analysis provides insights on how DH system can provide regulating power as well as the impact of uncertainties and renewable sources on the planning. Furthermore, the case study shows the benefit in terms of cost reductions from considering a portfolio of units and both markets to adapt to RES production and market states.

The Benefits of Local Cross-Sector Consumer Ownership Models for the Transition to a Renewable Smart Energy System in Denmark. An Exploratory Study

“…The main reason behind those authors' arguments is that, in a co-ownership configuration, there is only one decision-maker for the investments in and operations of the wind turbines, the P2H units, and the rest of the components of the DH system (e.g., thermal storage, solar collectors, combined heat and power (CHP) plants, etc. ), which are regarded as parts of the same system [22]. This facilitates the coordination.…”

“…DH companies determine their optimal operational strategy (i.e., the one that meets the heat demand at the lowest possible cost) for the portfolio of technologies available and for every hour [22]. In Denmark, the portfolio may consist of CHP units, boilers, P2H units, solar collectors, waste heat from nearby companies, and thermal storages [14].…”

“…In Denmark, the portfolio may consist of CHP units, boilers, P2H units, solar collectors, waste heat from nearby companies, and thermal storages [14]. Therefore, the calculation of the optimal operational strategy may include production and storage capacities, demand estimation, sun energy resource estimation, and fuel, heat, and electricity prices [22]. In the case of Hvide Sande, where the DH company also owns wind turbines, the calculation also includes wind resource estimation, the market price wind power could get, and the cost of self-consuming the wind power [22].…”

“…Therefore, the calculation of the optimal operational strategy may include production and storage capacities, demand estimation, sun energy resource estimation, and fuel, heat, and electricity prices [22]. In the case of Hvide Sande, where the DH company also owns wind turbines, the calculation also includes wind resource estimation, the market price wind power could get, and the cost of self-consuming the wind power [22]. In this case, the operational strategy defines, among others, when to sell the wind power in the electricity market and when to self-consume it [22,29].…”

“…In the case of Hvide Sande, where the DH company also owns wind turbines, the calculation also includes wind resource estimation, the market price wind power could get, and the cost of self-consuming the wind power [22]. In this case, the operational strategy defines, among others, when to sell the wind power in the electricity market and when to self-consume it [22,29]. This means that, as suggested by the theoretical approach presented in Figure 1, the operation of the wind turbines and the P2H unit are different in the co-ownership solution implemented in Hvide Sande and the separate ownership solution that is currently the norm.…”