Demonstration of a unique process for large scale Underground Energy Storage (UPHS)

PROJECT DESCRIPTION

BACKGROUND

The amount of energy produced by renewable energy is rapidly increasing as fossil fuel sources are phased out. However, renewable energy sources, such as wind and solar power, are often unreliable due to variations in the amount of electricity produced not aligning with consumer usage. Therefore, backup sources are needed to compensate when the demand cannot be matched. In 2018, pumped hydro solutions (PHS) represented over 94% of total installed energy storage capacity globally. A PHS system consists of two reservoirs located at different altitudes. However, traditional pumped hydro solutions have large environmental drawbacks due to the need to build new dams and to flood some areas. By locating the pumped hydro plant in an abandoned or inactive mine, existing infrastructure can be used. The tunnel network of a mining facility has chambers that can be used as reservoirs, and in some cases the mine dam can be used as an upper reservoir. Combined with a pit connecting the two locations used as reservoirs, no or minimal excavation activities are required and the environmental impact is minimised.

OBJECTIVES

The overall objective of the LIFE UPHS project is to demonstrate a highly innovative method for large-scale underground energy storage, which utilises abandoned or inactive mines. The aim is to enable energy storage with 70-80% round-trip efficiency.

The project includes the following specific objectives:

To verify the innovative concept at pilot scale (5%) and under full operating conditions in connection with an existing wind farm in Sweden;

To develop and verify a standard design concept that can be used for construction of full-scale facilities once new locations have been identified;

To disseminate the outcome of the project to potential stakeholders and target groups in Europe; and

Perform a fast replication and commercialisation, based upon the results of the demonstration.

The project will support EU climate objectives by aiming to verify a new solution for increasing the production, storage and consumption of renewable energy. It addresses the concern, raised in the Energy Roadmap 2050 (COM(2011) 885), that making full use of renewable energy storage technologies is critical, but they are currently often too expensive.

RESULTS

Expected results:

Generation of 1 000 MWh in frequency regulation as a result of underground storage of energy from renewable sources;

500 frequency regulations of the plant per year;

Reduction of CO2 emissions: 410 tons/year compared to coal generation of the same capacity;

Support stabilisation of 20 000 MWh of wind power from an existing wind farm;

Cleaning of 16 000 m3 of water during demonstration;

Prove profitability of 10% if the facility is scaled up to full-scale (50 MW); and

Two customers for full-scale plants upon completion of the pilot project.