Environmental Monitoring using off-shore wind and tidal power optical fibres

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The International Energy Agency states that we cannot achieve net zero ambitions by 2050 without Carbon Capture, Use & Storage (CCUS). Subsurface geological storage reservoirs must be monitored so that regulators can ensure security of the store, and operators can engineer reservoirs to avoid CO2 leakage. So there is a need to develop accurate and economical subsurface monitoring techniques. In parallel, tidal and particularly wind energy generation quadrupled in the past decade, with the expected capacity for wind energy to double again by 2030, according to Scottish Renewables. Yet three major off-shore areas proposed for wind farm development occupy areas related to CCUS (NSTA, 2022). Seismic subsurface CO2 monitoring vessels cannot operate close to wind farm infrastructure, and turbine noise raises concerns over signal to noise and repeatability requirements for seismic data. Novel technology from NOC has for the first time allowed signals from acoustic and seismic waves to be recorded every metre and every millisecond along optical fibres bound to power cables. They cross the seabed from land to tidal and wind farms, even up to individual turbines above the water surface. The ability to detect waves along the length of each fibre creates a new, densely distributed network of big-data sensors to monitor the solid Earth, ocean acoustics, and atmospheric sound off-shore. This relatively unexplored capability allows wind-farm noise to be recorded in real time so that it can be removed from seismic data to improve subsurface monitoring. The turbine noise itself is potentially a seismic source to monitor the subsurface, using seismic gradiometry, interferometry and neural network tomography of the recorded noise (Cao et al., 2020; Zhang et al., 2020; Zhang et al., 2022). This project will investigate these methods and develop others to improve subsurface CO2 monitoring, to monitor ocean acoustic signals from marine life and human activity, and to analyse acoustics in air above the sea and on land around power cable landing stations to detect human and other activity. Research questionsThe project aims to use signals recorded by optical fibres deployed at wind farms for environmental monitoring. This can include monitoring of the subsurface, marine life, ocean dynamics or human activity, and will develop as the project progresses. MethodologyYou will begin by exploring the signals of wind turbine noise recorded on optical fibres deployed on the seabed and on the turbines themselves. You will then explore using this noise as a seismic source to monitor the subsurface. You will also explore other signals recorded by the optical fibres, which could include signals from marine life, human activity, ocean currents and microseismicity. A variety of tools are available to assist in this analysis.