Our first full-scale project

Staříč Mine, Czechia

We are well advanced in the pre-selection of sites suitable for a 4-8MW single weight project which will deliver up to two-megawatt hours (MWh) of energy storage. Future multi-weight systems could have a capacity of 25MWh or more.

In Czechia, our engineers have scoped the Staříč mine in the Moravian Silesian region [pictured], where six deep mining sites were formally transitioned into a post-mining phase in early 2021.

On-site, they investigated the mine shaft, traveling to a depth of over 1km underground, and met state-run mine owners DIAMO, along with the regional government and local stakeholders including VSB Technical University of Ostrava.

The Staříč mine lies within a large coalfield that extends across the border into Poland and is one of a number of mainland European sites shortlisted. We plan to make a final site decision early next year. We expect to make a final site decision soon, with the project receiving Project Development Assistance from the European Investment Bank / EU Innovation Fund.

In Poland there are also more than 30 recently decommissioned mines, and worldwide we estimate there are around 14,000 mines that could be suitable for gravity energy storage.

In South Africa, we are engaged with a number of globally recognised mining houses and are supported through the Innovate UK’s Energy Catalyst program. This has led to the development of in-country partnerships with project development and mining specialists.

Our 250kW Edinburgh demonstrator

Gravitricity’s Edinburgh Demonstrator

During 2021 we successfully constructed, commissioned, and operated a 250kW, grid-connected demonstration project using a 15 metre high rig at the Port of Leith, Edinburgh.

The demonstrator uses two 25-tonnes weights suspended by steel cables. In a series of tests, we dropped the weights together to generate full power and verify our speed of response.

We then ran tests with the two single weights, dropping one after the other to verify smooth energy output over a longer period, alongside a programme of other tests to demonstrate and refine the full capabilities of the system.

This three-month test programme has confirmed our modelling and gives us valuable data for our first full-scale project in mainland Europe.

Knapton Energy Park – Multi-Weight Project

Gravitricity’s “Multi-Weight” Storage System

Gravitricity is currently working on a groundbreaking project at Knapton Energy Park, near East Knapton in Yorkshire to design and build a first “multi-weight” gravity based energy storage system.

The project, which is part funded by the UK Government’s Department for Business, Energy and Industrial Strategy (BEIS) will deliver up to 4MWh of electricity storage and will demonstrate Gravitricity’s ability to deploy systems that use multiple weights (lowered one after the other with consistent power output) in new purpose-built shafts to store energy and provide grid balancing services.

By using multiple weights, the system is able to greatly increase energy storage capacity through the increased mass in the system, without the need for multiple complex winch systems. As a result, the levelised cost of storage becomes more and more attractive as the system is scaled up.

Other full-scale projects

Gravitricity’s 1 Shaft, 3 Uses System

Along with environment consultancy Arup, we recently secured £299,985 from the Department of Business Energy & Industrial Strategy (BEIS) to study the feasibility of purpose-built underground shafts where gravity storage could be combined with hydrogen and inter-seasonal heat storage.

If successful, the project could be selected to enter Phase 2 of the Net Zero Innovation Portfolio Low Carbon Hydrogen Supply 2 Competition, where the partners would build a £multi-million scale demonstrator in the UK.

This would involve sinking a purpose-built concrete lined vertical underground shaft with a domed cap, to create a demonstration pressurised hydrogen storage vessel.