To correct grid imbalances and avoid grid failures, the transmission system operator (TSO) deploys balancing reserves and settles these imbalances by penalizing the market actors that caused them. In several countries, it is forbidden to influence the grid imbalances in order to let the TSO retain full control of grid regulation. In this paper, we argue that this approach is not optimal as market actors that trade imbalances under the supervision of the TSO can help balancing the grid more efficiently. For instance, some systems such as solar farms cannot participate in the standard balancing market but do have economic incentives to help regulate the grid by trading with imbalances. Based on this argument, we propose a new market framework where any market actor is allowed to trade with imbalances. We show that, using the new market mechanism, the TSO can keep full control of the grid balance while decreasing the balancing cost. This is of primary importance as: 1) novel approaches to reduce grid imbalances are needed as, while renewable sources are generally not used for grid balancing, the increasing integration of renewable energy sources creates higher imbalances. 2) While long-term storage of energy is key in the energy transition, it needs to become an attractive investment to ensure its widespread use; as we show, the proposed market can guarantee that. Based on a real case study, we show that the new market can provide 10–20% of the total balancing energy needed and reduce the balancing costs.

Electricity balancing is one of the main demanders of short-term flexibility. To improve its integration, the recent regulation of the European Union introduces a common standalone balancing energy market. It allows actors that have not participated or not been awarded in the preceding balancing capacity market to participate as voluntary bidders or ‘second-chance’ bidders. We investigate the effect of these changes on balancing market efficiency and on strategic behavior in particular, using a combination of agent-based modelling and reinforcement learning. This paper is the first to model agents' interdependent bidding strategies in the balancing capacity and energy markets with the help of two collaborative reinforcement learning algorithms. Results reveal considerable efficiency gains in the balancing energy market from the introduction of voluntary bids even in highly concentrated markets while offering a new value stream to providers of short-term flexibility. ‘Second-chance’ bidders further drive competition, reducing balancing energy costs. However, we warn that this design change is likely to shift some of the activation costs to the balancing capacity market where agents are prompted to bid more strategically in the view of lower profits from balancing energy. As it is unlikely that the balancing capacity market can be removed altogether, we recommend integrating European balancing capacity markets on par with balancing energy markets and easing prequalification requirements to ensure sufficient competition.

The authors provide a critical analysis of existing approaches to balancing and congestion management (specifically redispatch) and their effects on the incentives for service providers. This issue is particularly important in the view of the harmonization of ancillary service procurement in Europe, introduction of cross-border balancing markets and cooperation on congestion management. There is no universally established procurement mechanism for either of the two services. Based on case studies of Germany, France and the Netherlands and the introduction of an EU balancing energy platforms, we derive three stylized interaction models and discuss their comparative conflicts, risks and performance. We argue that market-based redispatch procurement can both increase allocative efficiency and resource availability as long as structural congestion is addressed first. Timeframe of procurement and remuneration mechanisms are other crucial factors affecting market efficiency. Combining redispatch with wholesale markets might yield a further improvement while minimizing conflicts between redispatch and balancing.

Market-based procurement of balancing services in Europe is prone to strategic bidding due to the relatively small market size and a limited number of providers. In the European Union, balancing markets are undergoing substantial regulatory changes driven the efforts to harmonize the market design and better align it with the goals of the energy transition. It is proposed to decouple the balancing energy (real-time) market from the (forward) balancing capacity market and the price of balancing energy will be based on the marginal bid. In this paper, the potential effects of these changes on market participants’ strategies are analyzed using an agent-based model. This model compares the effects of a standalone balancing energy market with different pricing rules on economic efficiency with agents that apply naïve, rule-based and reinforcement-learning strategies. The results indicate that the introduction of a standalone balancing energy market reduces the cost of balancing, even in a concentrated market with strategic bidders. Marginal pricing consistently leads to lower weighted average prices than pay-as-bid pricing, regardless of the level of competition. Nevertheless, in an oligopoly with actors bidding strategically, prices can deviate from the competitive benchmark by a factor of 4–5. This implies that the introduction of a standalone balancing energy market does not entirely solve the issue of strategic bidding, but helps dampen the prices, as compared to the balancing market prior to the design change.

At the forefront of energy transition, aggregators unlock value in front of and behind the energy meter. The business models of aggregators are changing rapidly, influenced by changes in technology, the market design, and regulatory framework. This chapter provides an overview of the leading aggregators in Europe and their underlying business models. Based on an assessment of changes in technology and regulation, the authors proceed to identify new opportunities for aggregators in the increasingly distributed energy system that deliver value to customers and the energy system as a whole.

The zonal electricity market design in the Central Western European electricity market relies on redispatching generation units after market closure to manage congestion within bidding zones, while congestion between the zones is handled using flow-based market coupling. The combination of internal congestion in the meshed European network with a growing share of renewables increases the frequency and magnitude of congestion events and limits cross-border trade. The growing costs of redispatching and the divergence between grid physics and zonal markets lead to welfare losses. This paper is the first to propose an approach to improve the combined efficiency of flow-based market coupling and redispatching. We develop a novel methodology for congestion management in a zonal market with flow-based market coupling in order to increase cross-border exchanges by integrating preventive redispatch into the day-ahead market. In this approach, a set of integrated redispatch units is selected based on their high potential to reduce congestion and, as a result, free up grid capacity for cross-border exchange. We use three multi-step optimization models to demonstrate the benefits of the enhanced zonal market with integrated redispatch by comparing it to the nodal market model and a zonal market model with flow-based market coupling. The case study demonstrates the potential of the proposed methodology to significantly increase cross-border capacity and reduce the need for costly ex post redispatch. The approach is shown to be a feasible option for improving European market integration and thereby to achieve overall welfare gains.

Thanks to new technological advancements and EU policy impulse, distributed energy resources (DER) are poised to become a viable alternative to conventional electricity generation for the provision of balancing services to transmission system operators. In this paper we show that the design variables that affect DER access to and participation in the organized balancing market include different features of auction configuration as well as a number of formal, administrative and technical aspects of market design. In a comparative case study of the balancing markets in Austria, Germany and the Netherlands, we determine the extent to which a given market design effectively facilitates DER participation. To structure this analysis, we designed an assessment framework that provides a comprehensive tool for the assessment of balancing markets in Europe vis-à-vis DER participation. Our results show that flexible pooling conditions, a higher bidding frequency and product resolution, and the authorization of non-precontracted bids, among others, can significantly ease DER integration in the market. Different design variables, however, can enhance or neutralize each other's effects, so their interrelations need to be taken into account in order to achieve an improved and harmonized balancing market design.