By Climate Scorecard UK Country Managers Thomas Christensen & Gwen Wren
Offshore Wind: Largest Source of Renewable Energy in the UK
Offshore wind is the fastest growing source of renewable energy in the United Kingdom. According to the IEA, 33% of the UK’s share of electricity generation in 2019 came from wind energy. The United Kingdom has been quite successful in boosting the production of offshore wind power and has become a global leader in this sector, generating enough electricity annually to supply 4.5 million homes.
The UK plans to decarbonize its economy and reach net zero by 2050 through committing to drive the growth of low carbon hydrogen and wind energy. The 10-point plant for a Green Industrial Revolution (November 2020) has stated expanding offshore wind production to 40 GW by 2030 with the creation of 60,000 jobs, including 1GW of floating wind. As a comparison, the UK already has installed over 12GW of onshore wind capacity. Additionally, the Energy White Paper (December 2020) announced the plan to quadruple offshore wind capacity to power all UK households. By 2050, offshore wind energy could generate 95GW, representing 80% of the country’s renewable portfolio according to the Climate Change Committee’s 6th carbon budget.
According to recent analyses by the Climate Change Committee, take-up or expansion of low-carbon energy with hydrogen represents close to 150 Mt of CO2eq (which would otherwise be let into the atmosphere through conventional energy modes) by 2050. The UK 10-point plan includes 5 GW of low carbon hydrogen production capacity by 2030, while the Energy White Paper has promised to allocate £240 million to a Net Zero Hydrogen Fund. A key aspiration for hydrogen production is to replace gas-burning boilers in homes, where the entire domestic gas grid and home boilers would be upgraded to use hydrogen.
It is important to remember that hydrogen is considered an indirect greenhouse gas with the potential to increase global warming and thus should only be one of many systems replacing fossil energy. While, hydrogen-based energy systems have lower climate impact than fossil fuel-based energy systems, hydrogen leakage during its synthesis, storage, and use can still pose a risk to climate change. In fact, a leakage rate of 1% of the produced hydrogen is equivalent to an impact of 0.6% of the fossil fuel system it replaces, while 10% leakage is equivalent to 6% of the impact.
- Sustainability: As Europe’s windiest country, the UK is not expected to run out of wind anytime soon. Although operational and maintenance servicing requires diesel-powered vessels, these can eventually adopt new form of renewable energy technology, which the case study will explore.
- Cost efficiency: Post-installation, the only real cost is maintenance of the wind turbines. Overall, prices have fallen from £120/MWh in 2015 to £40/MWh in 2019. Capital and operational expenditures reduce for the same amount of electricity as turbines increase in size. Taxpayers will start paying for building and operations of wind farms rather than fuel costs for fossil energy.
- Reduction of reliance on imported energy and increase of regional opportunities: Offshore wind energy projects can create a subsea system in the North Sea where interconnections increase efficient, integrated use of renewables both for the UK and parts of Europe. This can be done for example through multipurpose connectors with the Netherlands. Even though the UK has left The North Seas Energy Cooperation after Brexit, the European Commission plans both future negotiations on this specific partnership, as well as inclusion of an exception clause for UK participation when required by the EU.
- Combining wind with hydrogen: Offshore wind can be connected to electrolysis production for hydrogen. The cost of hydrogen is largely determined by the cost of renewable power such as wind energy (according to McKinsey’s Hydrogen Council Report).
Best Practice Case Study
THE DOLPHYN PROJECT: Deepwater Offshore Local Production of Hydrogen
This project is funded by the UK Department of Business, Energy and Industrial Strategy (BEIS), as part of their H2 (hydrogen) supply competition—a £33 million fund to accelerate the development of low carbon bulk hydrogen. It is currently in phase 2 (demonstration) and combines offshore wind power and delocalized production of green hydrogen which can be piped directly to shore.
DOLPHYN is a floating wind turbine project with three long-term aims: 2 MW proof of concept in 2024, a 10 MW pre-commercial unit connected to the low pressure gas distribution by 2026, and a complete capacity of 4 GW with various 10 MW floating turbines by early 2030s. The plan is to use an integrated water treatment unit and PEM electrolysers for localized hydrogen production off the coast of Aberdeen (Scotland) to supply heat and energy for transport. Desalination equipment on the floating farm would produce freshwater, which would in turn be separated into oxygen and hydrogen. The power unit is integrated on the floating turbine, making it completely autonomous (with routine servicing and operations).
The direct coupling method of the floating platform strategically avoids expensive cables associated with using a centralized hydrogen production (offshore or onshore) platform, rather it benefits from simply sending hydrogen to a sub-sea manifold (a router that connects subsea trees and flowlines) and then to the mainland. Another key advantage to the autonomous nature of these floating turbines is that they can be built far out at sea, avoiding shipping lines or concerned communities.
What makes this case study particularly promising is the fast-moving regional development of such innovations among European partnerships in the North Sea. The German Siemens Energy company is also developing an offshore turbine with a built-in electrolyser. A UK-headquartered energy firm is looking to convert an oil platform into a hydrogen production station to send hydrogen to The Netherlands via natural gas pipes. The Carbon Trust seeks to support such projects in ensuring a circular use of hydrogen by retrofitting windfarm operations (diesel powered transfer vessels or service operation vessels) with hydrogen co-combustion units or replacing units with fuel cell technology.