Energy storage plays a major role in the transition towards a net-zero emission energy generation systems. The lack of effective solutions in this regard may not only hinder but block the energy transition. Energy storage addresses several of the central principles in the Clean energy for all Europeans package and goals towards Stepping up EU 2030 Climate Ambitions and the New European Research Area with the ultimate objective to achieve a climate-neutral society by 2050. The development of renewable energy sources (RES) requires much more flexible energy systems than the existing ones in order to stabilize uneven energy production and demand and to ensure security of supply.​ The aim of the project is to investigate the possibility of using water reservoirs, such as those created after the closure of open-cast mines, to store energy.

In summary, the main objectives of the project are as follows.

• Construction and testing of small Pumped Hydroelectric Storage PAT unit (pump as turbine), demonstrator in mining areas.

• Development of a series of highly efficient PAT units that work both as a pump and a generator.

• Development of pipelines for small and medium size PHSs made of eco-friendly materials.

• Development of a database of possible locations of other similar installations along with the forecasted their power and capacity.

• Creating guidelines for duplication of the solution in other areas