Romania to turn 17 coal mines into gravity energy storage systems

Romania agreed with Australia-based Green Gravity to examine the possibility of installing gravity energy storage technology in 17 mine shafts in the country’s coal hub in the Jiu Valley.

Romania aims to quit coal by 2032 and replace thermal power plants using the fossil fuel with renewables, gas and nuclear power. But electricity production in wind and solar parks depends on weather conditions, so there is a need for massive energy storage capacities. The government decided to try a logical solution: make gravity energy storage systems in vertical coal mine shafts.

Pumped storage hydropower is still the only conventional technology in the sector. Batteries are gaining ground as they are produced relatively fast, though they are expensive and depend on lithium and other critical minerals. Companies around the world are testing the use of other materials. Some, like sodium, are showing potential for scaling up.

In the meantime, a different experimental approach to energy storage is emerging. Some firms are building towers with weights. They are lifted with excess power from renewables, and dropped at times of higher demand, producing electricity.

Ministry of Energy highlights deal as strategic agreement

Green Gravity from Australia turned to abandoned mines instead. The firm counts on millions of existing vertical shafts that can accommodate weights, which is much cheaper, takes up very little space on the surface and doesn’t require water and chemicals.

Authorized by the Ministry of Energy of Romania, state-owned coal mine operator Complexul Energetic Valea Jiului signed a framework cooperation agreement with Green Gravity. The deal envisages conducting a joint study to assess the technical, economic and environmental aspects of converting 17 shafts in CEVJ’s four existing coal mines in the Jiu Valley into energy storage facilities.

As a matter of fact, the ministry called it a strategic agreement.

Study to cover integration of gravity energy storage with renewables, grid

The study is also set to assess the integration of gravity energy storage with the existing electricity grid and renewable energy sources.

“I welcome this initiative, which demonstrates the potential for cooperation between Romania and Australia in the field of clean energy and climate action. I support the efforts of CEVJ and Green Gravity to explore the feasibility of gravitational energy storage using old mine shafts, which could provide a viable solution for enhancing the flexibility and resilience of our energy system, ensuring a future for the Jiu Valley, and progressively reducing our dependence on fossil fuels,” Minister Sebastian Burduja said.

Green Gravity highlighted its ambition to make the Jiu Valley a successful example of a coal region’s transition.