A question that has begun to haunt oil industry geoscientists — especially young professionals — is what a post-fossil fuel career might look like, assuming the pace of the energy transition intensifies.
David Hodgson, professor of sedimentology and stratigraphy, and his colleagues at the School of Earth & Environment, University of Leeds, are doing their bit to raise awareness of the growing number of wind farm installations across the globe as one promising area for the geosciences, even if modest compared with the massive oil and gas exploration business.
“The number of geoscientists working in the offshore wind farm space is growing,” Hodgson says. “But there is capacity for this to increase if the crucial role of geological knowledge is better recognised in improving long-term, sustainable, whole life-cycle management of the wind energy-generation infrastructure.”
He advocates a more multidisciplinary approach.
“The sustainable growth of offshore renewable-energy provision does not only require engineering solutions. It is essential that there is closer collaboration with geoscientists to build better ground models that capture the high level of heterogeneity, to predict changes in seabed sediment mobility at wind farms and cable routes, and to improve installation of onshore energy transmission and storage.”
Hodgson and colleagues recently published a journal article, Geoscience Solutions for Sustainable Offshore Wind Development, that describes how geoscience can contribute to offshore wind farm development, from planning to decommissioning.
It lists a broad range of applications, from estimating current and future wind resources to site assessment and energy storage using subsurface geo-assets such as depleted oil and gas reservoirs.
The review points to technology issues that continue to pose challenges even after 20 years of market expansion since Vindeby, the world’s first commercial offshore wind farm — now decommissioned — was installed offshore Denmark by Dong Energy, now Orsted, in 1991. Its capacity was 4.95 megawatts.
Advances in overall technology have been spectacular. Next year should see the Vestas V236-15.0 MW offshore wind turbine, currently under test, installed in the Frederikshavn wind farm offshore Denmark, making it the largest in the world.
China is developing an even grander-scale 18 MW capacity turbine. The Vestas unit has a rotor diameter of 236 metres and will be the tallest in the world, at 280 metres, powered by blades measuring 115.5 metres.
The opportunities for geoscientists are many.
Hodgson and University of Leeds researcher Natasha Barlow, as principal investigators, have launched a joint industry project on Geoscience and Offshore Wind.
Like oil and gas before it, the offshore wind industry is under pressure to be more environmentally and economically sustainable, benefit communities, and to develop a diverse workforce, while expanding into more challenging locations.
The idea of the joint industry project is to link university researchers with a consortium of 25 partners to turn research work into practice while targeting industry needs.
The stability of turbines is dependent on the sediments and detailed information is needed to calculate how deep turbine foundations need to go.
This applies equally to the tethering requirements of the emerging floating wind industry.
The Leeds University research has focused on the North Sea, inspired in part by new industry-generated seismic reflection data, available at a much higher resolution and at shallower depths than that used by the oil and gas industry.
The seismic reflection profiles form a dense 2D grid, with 100-metre horizontal spacing and a vertical resolution of less than one metre, for 100 to 200 metres depth.
This allows scientists to build detailed maps of former land surfaces and understand the complex depositional environment and the structure of the sediments.
Such information is crucial in a highly dynamic environment such as the North Sea, which has been shaped over millennia by ice sheets repeatedly advancing and retreating over Northern Europe, leaving mobile sand bodies that can scour at the base of wind turbines.
This exposes cables and decreases turbine lifespan, leading to early decommissioning, which is a major cost and has an environmental impact.
Hodgson says: “Our distinctive contribution is the understanding of the substrate and the impact this can have on the economics of installation. We are working more closely with the industry to have a stronger input on the geological controls so the best methods and materials can be chosen.”
Global installed offshore wind capacity is expected to reach 630 GW by 2050, according to McKinsey & Company, up from 40 GW in 2020, and with upside potential of 1000 GW if wind farm installation is considerably ramped up.
In 2019, energy produced from offshore wind was a modest 0.3% of global energy production, but among renewables it was the fastest growing.
Globally, 59.2 GW is fully commissioned; a cumulative 86.4 GW is operational, in construction or has reached the final investment decision stage.
Growth slowed last year, due mainly to volatile oil prices and supply chain constraints, according to data analyst company 4C Offshore, a TGS subsidiary.
4C Offshore notes that offshore wind remains attractive and competitive, evidenced by the multiple auctions and tenders expected in 2023. These include first auctions in Norway, Ireland, Uruguay, Lithuania, Colombia and Australia.
Also, the US Inflation Reduction Act (IRA) of last year, with its $369 billion investment in clean energy, is having a tangible effect on establishing a domestic supply chain.
The European Union recently proposed its own Net-Zero Industry Act, aiming to counter the IRA’s impacts on competitiveness and the volatile energy market with flexible state aid and increased grants and investments.