Battery energy storage is becoming an important asset in modern power systems. Considering the market prices and battery storage characteristics, reserve provision is a tempting play fields for such assets. This paper aims at filling the gap by developing a mathematically rigorous model and applying it to the existing and future electricity market design in Europe. The paper presents a bilevel model for optimal battery storage participation in day-ahead energy market as a price taker, and reserve capacity and activation market as a price maker. It uses an accurate battery charging model to reliably represent the behavior of real-life lithium-ion battery storage. The proposed bilevel model is converted into a mixed-integer linear program by using the Karush–Kuhn–Tucker optimality conditions. The case study uses real-life data on reserve capacity and activation costs and quantities in German markets. The reserves activation quantities and activation prices are modeled by a set of credible scenarios in the lower-level problem. Finally, a sensitivity analysis is conducted to comprehend to what extent do battery storage bidding prices affect its overall profit.

Transmission congestion must be managed so that transmission capacity is utilised as efficiently as possible with minimal social welfare loss usually by system operator. Congestion management must provide incentives for investments in transmission network and generation capacity in the right areas. Minimizing the risks associated with different congestion management methods is important task for every market participant who is trading between different areas. Risk management, in that case is focused on the managing of different trade arrangements with a goal of hedging against uncertainty trading with electricity across the border. The development of systems like contracts for differences, financial transmission rights, transmission congestion contracts and the like is very important for encouraging new operators to enter the business and for boosting trades on the official market. However, all contracts involve price setting, which is influenced by the parties negotiating power, so while they do cover the risk of fluctuating energy prices they fail to eliminate the exercise of market power and the exploitation of dominant positions. In this paper we discuss the differences between these solutions with a focus on risk management issues in three regions: Scandinavia, Continental Europe and South East Europe. We discuss market-based mechanisms such as implicit and explicit auctions, counter trade and/or redispatch from an economic viewpoint. The advantages and disadvantages of these methods are considered, and the costs and benefits are assessed. Special emphasis is put on risk management, because transmission congestion risks may expose market players to severe losses. We demonstrate the main issues with numerical and graphical examples. Our findings illustrate that the potential benefits of a co-ordinated congestion mechanism are increase of market competition, maximum interconnection usage, and reduction of market player risk as well as generation of revenue in market-based methods

Battery energy storage systems (BESS) and renewable energy sources are complementary technologies from the power system viewpoint, where renewable energy sources behave as flexibility sinks and create business opportunities for BESS as flexibility sources. Various stakeholders can use BESS to balance, stabilize and flatten demand/generation patterns. These applications depend on the stakeholder role, flexibility service needed from the battery, market opportunities and obstacles, as well as regulatory aspects encouraging or hindering integration of storage technologies. While developed countries are quickly removing barriers and increasing the integration share of BESS, this is seldom the case in developing countries. The paper identifies multiple case opportunities for different power system stakeholders in Croatia, models potential BESS applications using real-world case studies, analyzes feasibility of these investments, and discusses financial returns and barriers to overcome.

Hydrogen is one of the important factors in reaching climate neutrality from the European Green Deal, particularly hydrogen made from renewable energy sources. The paper describes electrolysis plants in technical, environmental and regulatory aspects and presents obstacles that need to be overcome for the successful implementation of electrolyser projects, looking at the bigger picture of the energy sector. Part of the paper is dedicated to the research of existing projects and the plans for the development of electrolysers. Possible contribution of the development of electrolysis plants is in the application at the locations of existing thermal power plants that are no longer suitable for operation due to technological, economic or environmental reasons, which would take advantage of the existing location of the power plant for the installation of new technology that meets the concept of low-carbon development.