With the Renewable Energy Expansion Act (EAG), Austria strives to achieve ambitious energy and climate policy targets, thereby taking the first step towards climate neutrality in 2040. The EAG requires an additional 27 TWh of generation from renewable energy sources (RES) by 2030. In the long term, a conversion of the entire energy system (transport, industry, heat) and a reduction in import dependency is necessary. However, the variability of RES poses massive challenges to the power system - seasonal fluctuations lead to under-coverage in the winter months (annual peak load) and over-coverage in the spring and summer months. Long-term energy storage thus forms an essential part of maintaining security of supply in an efficient, sustainable and import-independent energy and electricity system.

The focus of the exploratory project MILES is on the determination of demand and a holistic assessment of different MLSTs considering the system requirements of the Austrian energy system and its development in terms of the EAG up to 2030. For this purpose, the objective function-dependent demand for MLSTs is determined by using the Austrian power system model LEGO and subsequently their economic viability is investigated. This is the starting point for the inclusive modelling and determination of demand for long-term storage of a sector-coupled Austrian overall energy system.