A long-term unit commitment problem with hydrothermal coordination for economic and emission control in large-scale electricity systems

Abstract

The paper describes a long-term scheduling problem for thermal power plants and energy storages. In addition, renewable energy sources are integrated by considering the residual demand. Besides the classical minimization of the production costs, emission-related costs are taken into account. Thereby, emission costs are determined by market prices for CO 2 emission certificates (i.e., using the EU emissions trading system). For the proposed unit commitment problem with hydrothermal coordination for economic and emission control, an enhanced mixed-integer linear programming model is presented. Moreover, a new heuristic approach is developed, which consists of two solution stages. The heuristic first performs an isolated dispatching of thermal plants. Then, a re-optimization stage is included in order to embed activities of energy storages into the final solution schedule. The considered approach is able to find outstanding schedules for benchmark instances with a planning horizon of up to one year. Furthermore, promising results are also obtained for large-scale real-world electricity systems. For the German electricity market, the relationship of CO 2 certificate prices and the optimal thermal dispatch is illustrated by a comprehensive sensitivity analysis.

On the Structure of Decision Diagram–Representable Mixed-Integer Programs with Application to Unit Commitment

“…Due to the substantial cost savings resulted from high quality solutions of the unit commitment, a host of UCP formulations and solution techniques have been proposed to solve real-world instances; see Bertsimas et al (2012), Atakan et al (2017), Franz et al (2020), and Knueven et al (2020a), for successful implementations.…”

Annual dispatch strategy of integrated power systems with large-scale cascade hydropower

“…α is the binary variable to indicate whether the unit is online. Due to the mechanical structure, the ramping capacity of thermal units is limited, as shown in constraints ( 17) and (18). Other constraints in rolling dispatch are similar to those in annual fast dispatch, which will not be repeated here.…”

“…Reference [17] effectively optimizes the annual operation of hydropower with a logical optimization algorithm based on the rule of thumbs. Reference [18] introduces fast scheduling procedures based on heuristic approaches to determine the operational state of thermal units. Nevertheless, the methods are usually optimized on a daily basis or monthly basis, as well as lacking comprehensive scheduling plans of units, which is still hard to be adopted for the arrangements in real power dispatch.…”

Optimal bidding functions for renewable energies in sequential electricity markets

“…In most countries, multiple electricity markets coexist which are used sequentially by the market participants. Since the integrated or coordinated trading in these markets can dramatically increase the complexity of the decision problem, most authors focus on a single market setting, while other markets are (if at all) only included implicitly (e.g., Jiang and Powell 2015;Gönsch and Hassler 2016;Zhou et al 2016;Franz et al 2020;Ghavidel et al 2020;Finnah and Gönsch 2021). Like in sequential auction markets, a product can be traded multiple times in a continuous intraday market.…”