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21 February 2024 | News

Oxygen from electrolysers to the bottom of the Baltic Sea?

Can the excess oxygen released during hydrogen production at offshore wind farms benefit the Baltic Sea marine environment? Researchers will find out in a new modelling study where they will study the effects of oxygenation of the deep waters of the Baltic Sea in the short and long term.

Oxygen from electrolysers to the bottom of the Baltic Sea?
Photo: An excess of nutrients in the Baltic Sea results in large algal blooms of cyanobacteria and large areas of oxygen deficiency at the seabed. In a modelling study, researchers will now investigate the effects on the marine environment of oxygenating the bottom waters of the Baltic Sea with oxygen, a by-product of hydrogen production from offshore wind power. Photo SMHI, data source: ESA, Sentinel 3A.

Due to eutrophication, the bottom waters of the Baltic Sea have become increasingly oxygen deficient, especially in the deepest parts of the southern Baltic Sea. The lack of oxygen disrupts the entire marine ecosystem.

Researchers from the Swedish Meteorological and Hydrological Institute (SMHI), among others, will now investigate the effect on the marine environment if the deep water is oxygenated with the oxygen released during hydrogen production from offshore wind power.

Modelling study provides a more reliable basis for decision-making

- We will study the effect of oxygenation in a calculation model over the entire Baltic Sea. Similar models are also used for forecasting and climate studies. In this case, we can add oxygen to the model by locally increasing the oxygen concentration and investigate how the oxygen level would be affected in the Baltic Sea over time. The results contribute to more reliable decision-making and are a good way to test an idea before conducting any on-site tests," says Sam Fredriksson, oceanography researcher at SMHI.

Why is this important?

- Areas with oxygen-poor bottoms are historically large, which can be seen, among other things, in the large algal blooms of cyanobacteria that have occurred over a number of years. It is therefore important, in addition to continuing to reduce nutrient inputs, to turn over every stone to see how the situation can be improved. By using modelling, you can apply the precautionary principle and find out the long-term effects before taking a possible next step," explains Sam Fredriksson.

Input data from planned wind farms

The researchers will receive input to the modelling calculations from the wind power producer OX2, planning to produce hydrogen in connection with the construction of new wind farms.

Researchers from SMHI are leading the project. Researchers from Stockholm University and the Norwegian research institute NORCE are participating, as well as the wind power producer OX2.

- "This can be a fantastic opportunity not only to produce fossil-free energy but also to contribute with nature-positive measures to recreate a healthier ocean. At the same time, any intervention in nature must be carried out carefully and gently. Therefore, we are very happy to work with SMHI to explore the possibilities of this technology," says Elina Cuellar, project manager, OX2.   

The project is one of five research projects that received funding from the Environmental Research Grant via the Swedish Environmental Protection Agency and the Swedish Agency for Marine and Water Management's call for research funding in offshore wind power. It will contribute to the necessary knowledge to be able to carry out environmental assessments and the Swedish Agency for Marine and Water Management's government assignment to produce a proposal for amended marine plans, where a major expansion of offshore wind power is included.

Read the press release here