Only with storage systems of the most diverse forms can the energy transition be mastered, experts agreed at the autumn meeting of ÖGEW and DGMK in Vienna.
At the autumn meeting of the Austrian Society for Energy Sciences (ÖGEW) and the German Scientific Society for Sustainable Energy Carriers, Mobility and Carbon Cycles e.V. (DGMK) in Vienna, the experts present agreed: storage systems in a wide variety of forms are indispensable for the success of the energy transition in general and for security of supply in particular.
Burcu Gunal, the Director General of WPC Energy (formerly World Petroleum Council), stated in her presentation that the world’s energy supply is undergoing a fundamental transformation that is currently having a serious impact on security of supply. New technologies are coming onto the market at an unprecedented speed. Renewable energies recorded a “record expansion” in 2024 – as did the demand for oil, natural gas and coal, but also the demand for electricity from nuclear power plants. “The challenge consists in aligning security of supply with sustainability goals, integrating renewable energies into the grids without endangering their reliable operation, and increasing the flexibility of the systems in order to cope with extreme volatilities,” Gunal emphasized. Storage technologies, digitalization and decentralized generation would therefore become key factors for the success of the energy transition.
In particular, storage facilities are developing more and more into the “backbone” of energy systems, according to Gunal. Without storage, decarbonization is delayed, its costs increase, and the reliability of supply decreases, according to the Director General of WPC: “With storage, however, we can reconcile demand and supply, as well as volatility and reliability.” More than ever, coordination between politics, financing and technology is required for this, Gunal made clear. After all, the security of energy supply is based on cross-border cooperation, transparent markets and the exchange of knowledge. “Energy storage is no longer merely a supporting technology,” Gunal emphasized: “It provides the necessary flexibility to reliably supply society and the economy with energy.”
Elisabeth Zehetner, the state secretary responsible for energy policy in the Austrian Ministry of Economic Affairs (BMWET), who belongs to the conservative Austrian People’s Party (ÖVP), argued in a similar way. According to her, Austria has relied predominantly on high-performance pumped-storage power plants in the mountainous regions in the west and south of the federal territory for decades. However, other technologies are also becoming increasingly important. The government plans increased incentives for small storage facilities. For example, photovoltaic systems are to be subsidized in the future only if their operators also install electricity storage units. With the upcoming Electricity Industry Act (ElWG), grid-supporting storage facilities will be exempted from grid tariffs: “We must use electricity storage units to relieve the grids. It must not be the case that small storage units in particular are already fully charged at 9 a.m. and are no longer available for compensating the ‘midday peak’ in generation.”
In the case of natural gas storage, Austria has a capacity of around 100 billion kWh, which clearly exceeds domestic gas demand of just under 80 billion kWh. In the future, according to Zehetner, it will be necessary to use these volumes for the seasonal storage of (green) hydrogen as well. Promising pilot projects are underway, the state secretary noted: “And we as the federal government are working on the framework conditions for hydrogen as an energy storage medium.” This concerns the planned “Renewable Gas Act” (EGG) as well as the emerging hydrogen import strategy.
Austria has no shortage of examples of pilot projects in the field of new storage technologies. For about ten years, the Rohöl-Aufsuchungs-Gesellschaft (RAG) has been working on the use of natural gas storage facilities for the seasonal storage of hydrogen, reported Markus Pichler, one of its experts in this field. With the project “Underground Sun Storage 2030,” completed this year, RAG succeeded in demonstrating the technical feasibility of seasonal hydrogen storage in depleted gas reservoirs. An EU-funded project called EUH2STARS has started, according to Pichler. Its purpose is to further improve the technology and bring it to industrial maturity. “Essentially, we are ready for commercial hydrogen storage,” Pichler assured.
Wien Energie, in turn, is working on the development of a scalable pit storage facility designed to support the company in decarbonizing district heating. According to the responsible advisor Marieluise Pöschko-Reinweber, the aim is ultimately a storage volume of up to 500,000 cubic meters. Water with a temperature of up to 95 degrees Celsius is to be stored. The construction of a pilot plant with a volume of 40,000 cubic meters, 20 MW of thermal capacity and an energy content of around 2,000 MWh at the site of the Wien-Donaustadt gas-fired power plant is scheduled to begin in 2026, subject to internal corporate approval, and to be completed in 2029. Special innovations include a floating “lid” of the cylindrical storage unit, which is embedded in the ground, is walkable, and on which, according to visualizations, PV modules could be installed.
Energy storage facilities are also indispensable for the reliable operation of Austria’s transmission grids, emphasized Kurt Misak, the head of the division for security of supply and operational energy management at the transmission system operator Austrian Power Grid (APG). According to him, pumped-storage power plants currently dominate, with a turbine capacity of a total of about 9,000 MW and a pumping capacity of 4,300 MW. They are contrasted with volatile generation capacities of around 13,800 MW, of which PV systems account for 9,500 MW and wind farms for 4,300 MW. These are essentially concentrated in the northeast of Austria, whereas the pumped-storage plants are located in the west and southwest of the country.
According to Misak, the capacity of the transmission lines between eastern and western Austria is around 3,000 MW. It must be urgently increased, especially since it is planned to increase the capacity of PV systems to around 41,000 MW by 2040 and that of wind farms to 12,000 MW. APG therefore plans to invest around 9 billion euros in the expansion and reinforcement of its grids by 2033. “In the end, the success of the energy transition will be decided in the electricity grid,” Misak emphasized.
