The technology necessary for ‘meshed grids’ – with clusters of offshore windfarms connected to offshore hubs that are connected to each other and to more than one country – is ready. Now political support for the concept and pilot projects are required to bring the concept to reality, an EU-funded research project has found
The results of the Progress on Meshed HVDC Offshore Transmission Networks’ (PROMOTioN) project were presented on 21 September 2020 at the end of the project conference.
The event, titled North Sea Grid for the European Green Deal: How to unlock Europe’s Offshore Wind potential – a deployment plan for a meshed HVDC grid, marked the culmination of more than four years of research and full-scale technology demonstrations on integrated offshore HVDC transmission systems. The project brought together 34 international project partners across the industry value chain.
The project demonstrated that the technologies necessary for a meshed HVDC transmission network for offshore wind are ready, but that political will and further European co-operation are needed to develop the regulatory and technical frameworks necessary to implement them.
Co-ordinated, multipurpose, interconnected HVDC transmission infrastructure is the optimal way to integrate offshore wind into transmission infrastructure, the project partners believe, and joint European offshore wind and transmission projects should be an ‘essential component’ of a green recovery from the Covid-19 pandemic.
As a first step, said the project partners, real full-scale cross-border pilot projects need to be implemented to gain practical experience and demonstrate the real-life benefits of multi-terminal grid development. In parallel, work on a uniform grid code and operating guidelines needs to be initiated.
German Ministry of Economy and Energy State Secretary Andreas Feicht said, “The PROMOTioN project has played an important role providing input on how offshore wind and the necessary grids and market rules need to be established. The results of the project are very timely.”
European Commission Director of Internal Energy Market at DG Energy Catharina Sikow-Magny said, “Offshore renewable energy is at the core of the transformation of the energy sector and reaching the European climate goals.
“Offshore wind will play a key role in the decarbonisation of the wider economy through increased electrification of other sectors as well, such as heating and transport.
“Europe needs strong co-ordination and co-operation on planning processes beyond national borders to be able to tap into the potential of offshore renewable energy.”
In a conventional transmission system, offshore wind export links and interconnectors have been realised as ‘point-to-point’ connections, but meshed offshore grids can enable efficient, economic and reliable transmission offshore, the project partners say, and HVDC will be required because of the high levels of power involved and great distances over which it will need to be transmitted. This will make it necessary to use converter stations on and offshore.
Since 2016, the project partners have been working on solutions for meshed offshore HVDC transmission networks. They have developed and tested reliable HVDC network protection and control solutions, worked on interoperability and standardisation of key components, and outlined recommendations for an EU-wide regulatory and financial framework. They have also developed a deployment plan and a roadmap for implementation of meshed grids in the period to 2050.
The project partners have also conducted full-scale demonstrations of HVDC system controls, protection systems, gas-insulated switchgear, and HVDC circuit breakers.
The project has demonstrated that HVDC circuit breakers and gas-insulated substations are ready for use and can be manufactured immediately. Software-based technology such as HVDC control systems and HVDC system protection have been proven to work and to be interoperable, and are ready for a real-world pilot.
Full-scale pilot projects at sea would accelerate the development of uniform DC grid code and help to specify system operation guidelines. It would also bring about agreement on high-level technical system characteristics, such as operational configurations, voltage levels, system earthing, and converter configurations.
“Clear support and affirmation from politicians regarding the regulation and market models of the meshed grid and more co-operation at a European political level as well as at the level of network operators is absolutely necessary,” said the project partners, and the UK and Norway should be included in the development of joint offshore wind transmission grids in the North Sea and Irish Sea.