Edinburgh energy storage start-up Gravitricity has signed a land rental agreement with Forth Ports to build their first demonstrator project on land within the Port of Leith.

Work will begin on the £1 million project in October, on an industrial site at the Port of Leith [Bath Road] with plans to be up and running by late December.

The 16-metre high rig will utilise the port’s extensive electrical network and grid connections and will be used to demonstrate the speed of response of their innovative energy storage system.

Gravitricity’s energy battery works by raising multiple heavy weights – totalling up to 12,000 tonnes – in a deep shaft and releasing them when energy is required. They plan to roll out their technology in disused mine shafts worldwide.

The demonstrator at the Port of Leith will allow the technology to be trialled on a much smaller scale, utilising an above ground structure.

Commenting on the project, Gravitricity Lead Engineer Miles Franklin said:

“This grid-connected demonstrator will use two 25-tonnes weights suspended by steel cables. In our first test we’ll drop the weights together to generate full power and verify our speed of response. We calculate we can go from zero to full power in less than a second – which can be extremely valuable in the frequency response and back-up power markets

“We will then run tests with the two single weights, dropping one after the other to verify smooth energy output over a longer period. Together, this two-month test programme will confirm our modelling and give us valuable data for our first full-scale 4MW project which will commence in 2021.”

The lattice tower is being delivered by Leicester firm Kelvin Power, with the winches and control system supplied by Gravitricity’s strategic partner, Dutch winch specialists Huisman. The company is also in discussion with a number of Scottish businesses regarding the supply of other key components including the weights.

The project is supported by a £640,000 grant from UK Government funder Innovate UK.

KEY FACTS

• Rig height – 16 metres
• Weights – 2 x 25 tonnes
• Weigh composition – steel vessels filled with iron ore
• Cables – steel
• Stroke – 7 metres
• Time to drop (full power – 250kW) – 14 seconds
• Half power (125kW) – 28 seconds

See a short (30 second) explainer animation here.

See a longer (4 minute) explainer animation here.

Commenting on the Leith site, Gravitricity Project Development Manager Chris Yendell [pictured], said:

“The Port of Leith is an ideal location – it offers a grid-connected site with concrete hardstanding very close to our office base. Forth Ports have granted us a licence to occupy and have been supportive throughout.”

Stuart Wallace, Chief Operating Officer, Forth Ports, said:

“We are pleased to be working with Gravitricity and providing an area of land to facilitate the construction of the demonstrator unit.  Forth Ports’ Scottish operation, including the Port of Leith is continuing to work with developers and operators within the renewable energy sector, as we all work towards achieving the net zero targets set by the Scottish Government.”