The need for electricity is increasing at a rapid pace – but the green transition has not gone as fast as many had hoped.
In the north of Sweden, 25 miles west of Umeå, a pumped power plant that has been closed for almost 30 years is being restored.
– We have scanned all dry areas and the external waterways and now we are in the process of scanning the external waterways with the help of a remote-controlled submarine, says Mats Hägglund who is the project manager for Juktan Pumpkraftverk.
The pumped power plant in Juktan, which is unique with its three connected lakes, was in operation from the 1970s until 1996. Then Vattenfall decided to shut down the plant after the electricity market was deregulated and the power plant was no longer considered profitable.
Now, three decades later, it is again seen as a potentially valuable energy resource for the energy market of the future.
Energy pantry
The principle behind a pumping station is that water is pumped up from a lower-lying lake to a higher-lying lake during periods when electricity prices are low and the demand for electricity is less.
Then, when electricity demand increases and prices are high, the water is released back through the turbines to generate electricity. In Juktan’s case, it is about pumping water up to Blaiksjön, which is higher up in the terrain.
The power plant thus functions as a form of energy storage, where the water can be used to generate electricity when it is needed most.
Extensive work is underway
Intensive work is currently underway to examine and renovate the power plant’s old infrastructure. 260 meters underground, experts work to inspect tunnels, machines and spaces. Modern technology is also used to digitally scan the entire plant and ensure that everything is working properly before the power plant can resume full operation.
The goal is for the power plant to be in operation within the next 10 years. This is seen as a welcome addition, especially in research, which sees great potential in the technology to help balance Sweden’s electricity grid.
– The capacity is about one third of a nuclear power plant, so you can contribute with extra production when needed and the storage capacity is also very large, says Lennart Söder, professor of electric power engineering at the Royal Institute of Technology (KTH).
Challenges remain
Despite the optimism, major challenges remain to be resolved. Environmental requirements are significantly stricter today than when the power plant was first built, and one of the biggest challenges is dealing with the old mine waste dump in one of the lakes.
Approximately one million tonnes of enrichment sand is located here, which contains environmentally hazardous substances such as arsenic, zinc and nickel.
– When we move the sand during the construction period, we believe that the levels will rise slightly, but then we will install a treatment plant in the lake, says Mats Hägglund, who is the project manager for Juktan’s Pumpkraftverk.