The demand for renewable energy has led to a large-scale deployment of offshore wind farms, particularly in Northern Europe. The extent of the electrical cabling in the marine environment is unprecedented, and this has led to questions about whether there are any interactions between the electricity produced and the surrounding environment. A summary of the electric and magnetic fields generated by such cables is presented based on a research project using an analytical method to set up the problem which was then quantified numerically using the finite-element method. An industry standard 132 kV XLPE three-phase submarine cable buried at a depth of 1 m was modelled as an example. The results showed that a cable with perfect shielding does not generate an electric field (E field) outside the cable directly. However, a time-varying magnetic field (H field) is generated by the alternating current in the cable, which in turn generates an induced E field in the local environment. The results are considered in terms of environmental impact assessment relevant for the power delivery community.
Collaborative Offshore Wind Research into the Environment (COWRIE)
The objective of this paper was to summarize an investigation of the EMF generated by an integrated off-shore windfarm cable using both theoretical/analytical and numerical methods.
The results of this study provide quantitative evidence using analytical and numerical simulation the EMFs will be present within the sea bed and seawater around three-phase HVAC cables. The magnetic fields generated by the AC in the Cable and the induced electric fields due to the changing magnetic fields are within the detectable range for EMF sensitive species.
Gill, A.; Huang, Y.; Spencer, J.; Gloyne-Philips, I. (2012). Electromagnetic Fields Emitted by High Voltage Alternating Current Offshore Wind Power Cables and Interactions with Marine Organisms. Electromagnetics in Current and Emerging Energy Power Systems Seminar, London, UK.