MINEX Forum

Tag: renewable energy storage

  • This disused mine in Finland is being turned into a gravity battery to store renewable energy

    This disused mine in Finland is being turned into a gravity battery to store renewable energy

    One of Europe’s deepest mines is being transformed into an underground energy store. It will use gravity to retain excess power for when it is needed.

    The remote Finnish community of Pyhäjärvi is 450 kilometres north of Helsinki. Its more than 1,400-metre-deep zinc and copper Pyhäsalmi mine was decommissioned but is now being given a new lease of life by Scotland-based company Gravitricity.

    The firm has developed an energy storage system that raises and lowers weights, offering what it says are “some of the best characteristics of lithium-ion batteries and pumped hydro storage”.

    How does the gravity battery work?

    When there is excess power – from wind turbines on a windy day for example – weights would be winched up the Pyhäsalmi mine’s 530-metre auxiliary shaft. To generate energy these weights can be released. This turns the winches into generators, creating either a short burst of electricity or a slower trickle depending on what is needed.

    The gravity energy system would be able to store 2MW of power and integrate into the local energy grid.

    A study published by a team of international researchers last month found that gravity batteries in decommissioned mines could offer a cost-effective, long-term solution for storing energy as the world transitions to renewable power.

    Scientists from the International Institute for Applied Systems Analysis (IIASA) found that the world’s abandoned mine shafts could store up to 70TWh of power – roughly the equivalent of global daily electricity consumption.

    Bringing ‘low carbon’ jobs to a mining community

    The local community in Pyhäjärvi has set up a development company to promote regeneration at the old mine. It has just signed an agreement with Gravitricity to transform the old mine shaft into the first full-scale prototype of the company’s technology.

    They “anticipate this could become Europe’s first Gravistore deployment”, according to the company.

    “This project will demonstrate at full scale how our technology can offer reliable long-life energy storage that can capture and store energy during periods of low demand and release it rapidly when required,” Gravitricity’s executive chairman Martin Wright said.

    “This full-scale project will provide a pathway to other commercial projects and allow our solution to be embedded into mine decommissioning activities, offering a potential future for mines approaching the end of their original service life.”

    Wright also adds that the project will hopefully provide “low carbon jobs” in an area suffering significantly from the end of mining operations.

    The mine was opened in 1962, extracting more than 60 million tonnes of ore over its lifetime. Once a major employer in the region, it closed in August 2022 leaving many unemployed.

    The gravity battery is one of several community-driven projects at the mine aimed at breathing new life into the area. It includes a solar farm, tech startups and an underground 5G network.

  • Cornish Lithium secures £53.6m to open first mine for the metal in Britain

    Cornish Lithium secures £53.6m to open first mine for the metal in Britain

    The startup opening Britain’s first lithium mine in Cornwall has secured $67m (£53.6m) of investment led by the UK Infrastructure Bank, in a much-needed boost to efforts to extract the metal that is used for making vehicle batteries.

    Cornish Lithium is to receive the funds from the Treasury-funded bank and other investors as part of a larger funding package of up to $210m (£168m).

    The funding package is expected to speed up progress towards British mining of battery-grade lithium compounds, which are key to production of batteries for electric vehicles and renewable energy storage.

    The investment is part of a push to boost financing for climate crisis-related infrastructure projects, and to create a hub for supplies of lithium to Europe from Cornwall.

    The initial investment is led by the UKIB alongside the Energy & Minerals Group (EMG), a US private investment firm focused on energy and minerals, and TechMet, which invests in clean energy and electric vehicle technologies and counts the US government’s development finance corporation among its backers.

    The UKIB and EMG will each put in £24m while TechMet, Cornish Lithium’s largest shareholder, is investing a further £5.6m, bringing its total investment in the business to £30m.

    Core samples from Cornish Lithium’s exploratory drilling at its research site, August 2022.
    Core samples from Cornish Lithium’s exploratory drilling at its research site, August 2022. Photograph: Jim Wileman/The Guardian

    Cornish Lithium aims to increase its 70-strong workforce to more than 300 people once it is in commercial production. It had warned in its annual accounts in June that there would be material uncertainty over its future if it did not raise bridge funding by July to buy it time before its next fundraising round. The company plans to raise a further £6.9m by selling shares to small shareholders through Crowdcube, with a focus on existing investors.

    Lithium is a vital ingredient in the current generation of batteries used in portable devices ranging from mobile phones to electric toothbrushes. But vastly more lithium will be needed for electric vehicles as combustion engines are phased out around the world.

    Cornish Lithium is one of several projects that seek to revive Cornwall’s 4,000-year-old mining heritage. Another company, British Lithium, has teamed with the French mining firm Imerys to start a mine in Cornwall and to extract enough lithium to power 500,000 electric cars a year by the end of the decade.

    Jeremy Wrathall, founder and chief executive of Cornish Lithium, said it was “essential to secure funding from institutional investors with the financial muscle to bring our projects into commercial production”.

    He said the funds would enable the company to advance its project at Trelavour, near St Austell, to “construction-ready status” and allow it to “complete the engineering design work required to build a demonstration-scale geothermal waters extraction facility”.

    John Flint, chief executive of the UKIB, said: “Globally the supply of lithium is far outpaced by demand, and yet in the UK it remains a nascent market.”

    He said the investment would “greatly accelerate domestic production of a mineral which is critical to the future of electric vehicle battery production and decarbonisation of the transport sector”.

    Andrew Griffith, economic secretary to the Treasury, who visited Cornish Lithium on Tuesday, said the investment would improve the domestic supply of lithium, helping “the UK’s transition towards net zero whilst also boosting local and regional economic growth”.

    Kemi Badenoch, business and trade secretary, said that, coupled with Tata Group’s recent pledge to build a £4bn electric car battery gigafactory in Somerset last month, the investment would ensure the UK automotive sector is “well set for the future”.