Abstract
In the context of the extensive deployment of offshore wind farms (OWF), hydrogen (H2) is emerging as a promising energy vector to enhance electricity production from Offshore Renewable Energies (ORE).
This review highlights that offshore H2 production powered by OWF may intensify existing environmental pressures generated by OWFs (electromagnetic, noise and chemical emissions) while also introducing new pressures that impact local and regional hydrographic dynamics. Indeed, a significant environmental concern is the discharge of produced waters, consisting of high salt brine (from desalination) and heated water (from cooling), which could reach several tens of thousands of cubic meters per day for gigawatt-scale OWFs. These discharges may increase local salinity and temperature. Additionally, accidental risks include potential explosions of stored H2 and substantial spills of chemicals required for desalination.
This review underscores the critical lack of empirical data and scientific resources regarding certain environmental pressures, which hampers the ability to anticipate the potential impacts of offshore H2 production. To address this gap, a comprehensive data acquisition effort combining laboratory, in situ, and modeling approaches must be undertaken. Ultimately, this will enable the development of procedures for implementing relevant “Avoid, Reduce, Compensate” frameworks, thereby enhancing environmental integration of offshore H2 production.