Vattenfall launches pilot plant in 100GWh green hydrogen cave
The Swedish state energy company Vattenfall has commissioned a pilot plant for green hydrogen storage within a 100 GWh capacity.
The HYBRIT plant in Luleå, northern Sweden, is a collaboration between Vattenfall, the steel company SSAB and the iron ore producer LKAB.
It was inaugurated in June and, after initial pressure tests, has now been filled with hydrogen gas up to a maximum operating pressure of 250 bar. A two-year test period has now started and will last until 2024.
The technology will eventually move towards SSAB’s sponge iron production, but the wording of the announcement indicates that the next two years will mainly only test the hydrogen storage capacity. Sponge iron is produced by reducing iron ore to iron using a reducing gas or elemental carbon, and is used in the manufacture of steel.
The technology will be used on an industrial scale for the production of sponge iron at SSAB’s plant in Gällivare, a few hours north of Luleå, within the next four years, says Vattenfall.
The pilot plant is 100 cubic meters in size and could be expanded to 100,000 to 120,000 cubic meters. This would equate to 100 GWh of energy storage in green hydrogen form, which, according to a press release, was enough to supply a full-size sponge iron factory for three to four days.
Lars Ydreskog, head of strategic projects at LKAB, says: “Hydrogen and its storage are central to our transition. In just four years, the HYBRIT technology will be used for the production of fossil-free sponge iron on a large scale at a first demonstration plant in Gällivare. LKAB will become one of Europe’s largest hydrogen producers and this pilot project will provide valuable knowledge for the continued work of creating the world’s first fossil-free value chain for the iron and steel industry.”
Vattenfall said the pilot plant in Luleå is the first in the world to test the technology with repeated filling and emptying of hydrogen gas.
Other large green hydrogen storage cave facilities under development include the ACES Delta in Utah, USA, and the HyStock project in the Netherlands. ACES has a total storage capacity of 300GWh and is expected to come online in stages starting in 2025, while HyStock with a capacity of 26 million kg is expected online the following year. ACES will supply gas to a combined cycle power plant while HyStock’s developers have been vague about its use case.
The main use case for large-scale green hydrogen technology is as a feedstock for various industrial processes to help them reduce carbon dioxide, followed by replacing fossil fuel in transportation, and finally blending with natural gas for conventional gas-fired power plants.
Storing green hydrogen for conversion back to electricity — power-to-X-to-power — has a round-trip efficiency too low to be economical at present, most industry observers say.