Achieving Net Zero carbon emissions in the UK by 2050 will likely involve integration of very high levels of renewables into the wider energy system – particularly offshore wind generation.

Following the 2019 Sector Deal and recent successes in achieving major cost reductions, the government’s deployment target was increased to 40GW of offshore wind generating capacity by 2030, and beyond 2030 much higher deployment is possible.

However, the integration of very high levels of variable renewables into the wider energy system presents a considerable and multi-faceted challenge. The Offshore Wind Industry Council (OWIC) established a Task Force to ‘Solve the Integration Challenge’.

The work was delivered in two collaborating workstreams. Energy Systems Catapult delivered Workstream A.

Key points

The effect of wind generation on the system is dependent on the nature of the energy system into which that wind generation is deployed. A large number of possible systems were therefore modelled, and several scenarios were analysed in detail using Energy Systems Catapult’s cutting-edge modelling tools. The results included:

• Optimum system configurations consistently deploy at least 50-70GW of offshore wind generation by 2050. Credible systems are possible at significantly higher levels, with up to 150GW being modelled.  Significant further offshore wind development is therefore likely to be of benefit to the UK’s energy transition.
• Nevertheless, a diverse generation mix is preferable to over-dominance of any single generation technology. This mix should include clean thermal and nuclear plant.
• Hydrogen has an important role to decarbonise certain sectors, particularly industry and some transport and heating.
• Significant back-up plant, in the form of clean thermal generation, is required at high levels of offshore wind to cover rare, protracted winter periods of low wind.
• Extensive storage and flexibility is required, with electric, thermo-mechanical, thermal and gaseous storage all being deployed alongside interconnectors. Demand side management is important from domestic and district level thermal storage, as well as hydrogen production and storage.
• Some curtailment of offshore wind remains cost-competitive with alternative solutions.
• Both grid congestion and grid stability, connection and control challenges increase with high levels of renewables. The tools and techniques to manage these aspects (including a wide range of smart grid technologies and philosophies) already exist, and offshore wind can potentially contribute to the solution.
• To maintain grid reliability, procurement of greater volumes and different types of system services will be required, together with new control paradigms, traditional non-generating assets, storage, interconnection and smart grid solutions.
• The pace at which offshore wind can transition away from policy support is dependent on evolving the wider market and investment conditions – both for offshore wind and for the energy system more generally. Well-coordinated evolution of the policy and regulatory framework is therefore essential, in parallel with market design reforms.
• This transition depends on market arrangements that can unlock greater flexibility in supply and particularly demand – which could be provided by complementary assets and business models.
• Recommendations are therefore made for both near term CfD scheme evolution and longer term market vision, to encourage decarbonisation, flexibility, system integration and a reduction of market distortion effects. Additionally, some marginal but essential back-up plant may require out-of-market mechanisms to ensure security of supply.
• There are significant requirements and opportunities for further innovation across and beyond the energy sector. Recommendations are made spanning technological, organisational, and market, policy and regulatory spaces.