Battery-Powered SOVs, CTVs to Soon Become Cheaper than Their MGO Alternatives, Study Says

June 9, 2025, by Adrijana Buljan

Studies commissioned by ScottishPower Renewables found that battery-powered vessels (re)charging offshore is feasible and could be part of the operations of future offshore wind farms. One of the reports also says electric operations and maintenance (O&M) vessels will become cheaper than their Marine Gas Oil (MGO) alternatives within the next few years.

The offshore wind developer recently published the last two reports in a series of three studies it commissioned to look into options for decarbonising and reducing greenhouse gas (GHG) emissions from offshore wind farm operations.

The first study, conducted by Stillstrom, came out earlier this year, found that the electrification of offshore operations was technically feasible using battery-powered SOVs (e-SOVs), which stay out at sea for extended periods.

New Study Makes Case for E-SOVs Charging at Offshore Wind Farms

Vessels

The two new reports, by MJR Power & Automation and Oasis Marine, consolidated initial findings and also looked at the potential to decarbonise offshore operations using electric crew transfer vessels (e-CTVs) that could be used for wind farms located closer to shore, with findings confirming that this is technically and operationally feasible.

In both scenarios, offshore wind farms would also benefit environmentally and economically, with a significant reduction in both GHG emissions as well as fuel costs, ScottishPower pointed out in a press release on 4 June.

The MJR study found that electrical solutions are particularly suitable for offshore wind farm operations since vessels can regularly charge directly at offshore energy production sites and shore-based quay sides.

The study also identified that electric O&M vessels will become cheaper than their MGO alternatives within the next few years, with operating expenses already competitive with MGO-powered equivalents for SOVs, and fully competitive for CTVs in a couple of years.

In terms of vessel construction costs, taking into account Q4 2024 electrical systems pricing, e-CTVs currently require 14 per cent more CapEx than their MGO-powered equivalent, with similar ratios applying to E-SOVs. Looking at the steady trends for battery systems price reducing, coupled with energy density increasing, the cost difference will be eliminated and will even reverse within a relatively short time, the MJR report says.

The Oasis Marine study found that using e-CTVs, enabled by installing Oasis Power Buoys at the offshore wind farm, provides protection from volatile fossil fuel prices and the high costs of alternative green fuels, enabling costs to be predictable and in line with the operator’s business model.

Oasis Marine’s findings were based on the use of three electric CTVs instead of diesel-fuelled vessels at a case study wind farm. The study identified potential savings of 140,000 tonnes of CO2 emissions and fuel saving costs of around GBP 15 million (around EUR 18 million) over the wind farm’s anticipated 25-year lifetime.

“These latest studies have the potential to help the industry take a step closer to a new era for offshore windfarm operations – not just here in the UK, but right across the globe”, said Ross Ovens, ScottishPower Renewables’ Managing Director for Offshore.

“The valuable depth and insight this research offers – regardless of whether you’re considering an SOV or CTV operating model – could help inform future windfarm operations as the country continues to build the green generation we need to meet the expected doubling of electricity demand.”