Keywords: solar energy, storage, lithium batteries
Summary:Upper Austria is one of Austria’s nine federal states with a population of 1.4 million. It located in the northern part of the country, bordering Germany and the Czech Republic. Since the mid-90s, the government of Upper Austria has prioritized energy efficiency and renewable energy. Renewable energy currently supplies more than 32% of the total energy demand in the state, of which 16% comes from modern wood biomass, 11% from hydro power and about 5% from solar and other renewable energy sources. The high share of renewables in the energy mix was achieved through comprehensive state energy action plans. In these plans, the state follows a "sticks, carrots and tambourines" approach, a combination of regulatory, financial and information measures. Most of the energy programs are managed by the OO Energiesparverband, the state energy agency. The strategic approach to sustainable energy has also resulted in a robust growth of sustainable energy businesses. Over 250 companies are collaborate in the energy and environment business network, the Cleantech-Cluster. Photovoltaics are an important element in the energy transition, the process of phasing out fossil fuels from the energy system. The state has provided support to market development in the past decade, making Upper Austria a leading PV market. Currently 21.5 million ft² are installed, equalling an installed capacity of 14.8 ft² per inhabitant. To take sustainable energy market development to the next level, the state is implementing a support programme for solar batteries with lithium technologies. The aim of the program is to support innovation and kick-start market development in a very early phase. It supports households with an existing PV system to store the generated electricity in a battery storage, thus increasing the share of solar electricity that can be used on-site. In the Austrian climate, on average, households can only use 30-40% of the electricity generated by their PV-system (typically 3-5 kW). With a solar battery this can be increased to 60-70%. However, at the moment, the price for a stored kilowatt hour of electricity is still very high (32 US Cent/kWh). The support programme gave an incentive which reduced the price for a stored kilowatt hour of electricity to about 20 Cent/kWh = 21 US Cent/kWh) which is an average household electricity price in the state. The programme was very well received and in total more than 800 households participated (as of now, more than 600 batteries are already installed). A scientific evaluation of the performance of the systems is in place and provides valuable insights on battery technologies, performance and designing systems that will achieve high solar coverages.