A study1 carried out by the University of Applied Sciences Technikum Wien, AEE INTEC, BEST and ENFOS presents the market development of energy storage technologies in Austria for the first time. This study focuses on photovoltaic battery storage, heat accumulators in local and district heating networks, thermally activated building systems and innovative storage concepts. In 2020, Austria had a hystorically grown inventory of hydraulic storage power plants with a gross maximum capacity of 8.8 GW and gross electricity generation of 14.7 TWh. This storage capacity has already played a central role in the past in optimising power plant deployment and grid regulation. Additional storage capacities will also be required in both the electricity and heat sectors as part of the energy transition. The increasing linkage between sectors also gives rise to innovative approaches to the conversion and storage of energy.
Photovoltaic battery storage
Falling prices for battery storage systems, public subsidies and increased motivation on the part of private or commercial investors led to a strong increase in sales of photovoltaic battery storage systems in Austria in 2020. In 2020 for instance, 4,385 photovoltaic battery storage systems with a cumulative usable storage capacity of approximately 57 MWh were newly installed in the Austrian domestic market. Of these, approx. 94% were built with public funding and 6% without. The total inventory of photovoltaic battery storage systems in Austria therefore rose to 11,908 storage systems with a cumulative usable storage capacity of approx. 121 MWh. For 2020, a price of around € 914 per kWh of usable storage capacity excl. VAT was charged for PV storage systems installed as turnkey solutions. This means a price reduction of approx. 9.6% on the previous year 2019.
Heat accumulators in local and district heating systems
Of the total of 875 local and district heating networks surveyed, heat accumulators have been installed as an element of flexibility in 572 heating networks over the last 20 years. Tank water storage systems were used almost exclusively in terms of heat storage technology. However, the first anergy networks (cold district heating networks) have also been built over the last five years, using geothermal probe fields as seasonal storage for heat pump systems. The installation of new heat accumulators is usually directly related to the construction or expansion of heating networks. A total of 840 tank water storage systems in primary and secondary networks with a total storage volume of 191,150 m³ were surveyed in Austria. The five largest individual tank water storage systems have volumes of 50,000 m³ (Theiss), 34,500 m³ (Linz), 30,000 m³ (Salzburg), 20,000 m³ (Timelkam) and twice 5,500 m³ (Vienna). Assuming a temperature difference of 35 Kelvin, the storage inventory corresponds to a capacity of 7.8 GWh.
Thermally activated building systems
Heat and cold can be stored in buildings and sections of buildings. If buildings have a large mass and good thermal insulation, this results in thermal inertia that can be used for load shifting. Plastic hoses through which a heat transfer medium flows are installed in solid sections of the building. Load shifting is useful for the higher-level energy system if, for example, a grid operator is able to control the load to a certain extent via an interface. Activated components and buildings are usually heated and/or cooled with heat pump systems. As of 2015, heat pumps in Austria have been equipped with a corresponding smart grid interface. In total, this amounted to approx. 121,200 buildings at the end of 2020 with a maximum load shift potential of approx. 0.43 GWhel per hour of shifting time. The increase in this potential from 2019 to 2020 was approximately 20%.
Innovative energy storage systems
The examination covered hydrogen storage & power-to-gas, innovative stationary electrical storage systems, latent heat-accumulators and thermochemical storage. A total of 36 Austrian companies and research institutions were identified that research innovative storage technologies within these technology groups or offer these on the Austrian market. Most companies and research institutions are working on hydrogen storage, followed by innovative stationary electrical storage systems. A total of 17 stakeholders already offer storage on the Austrian market, with 19 actively involved in researching this. The sales figures for innovative storage systems are currently still low, but an increase is expected in the next few years.
1The documentation and analysis of the market development of selected storage technologies is based on research of the literature, expert interviews, evaluations of available statistics and empirical data collection.