Development of coupled offshore and onshore power grids

This project will create knowledge to support the development of power grids offshore as well as onshore, against a backdrop of large-scale offshore wind development and a changing onshore energy system. In 2022 the Norwegian government announced plans to award areas for 30 GW offshore wind power by 2040. This implies the emergence of an offshore power system with the same capacity as the existing Norwegian onshore power system. In other words, over the next decades, massive amounts of renewable energy from offshore wind need to be integrated into the Norwegian and European energy system. This should happen in a way that is economically efficient while at the same time ensuring security of electricity supply throughout the transition. For those who develop the grid, the guiding principle and a major challenge is to understand which grid development solutions are socio-economically favourable. This means that the solutions should promote the interests of the society, considering the aspects outlined above and more. Until now, offshore grid development has been restricted to single interconnectors and cables to/from shore for offshore wind farms or oil and gas platforms. With more offshore wind, a transition towards more varied and complex offshore grids is expected, with several interconnected sub-grids and offshore energy hubs, as well as interconnections to the onshore power grid of different countries. More knowledge is therefore needed about possible interdependencies, interactions, and synergies between offshore and onshore grids in the future. This project will develop methods for analysing different transition paths for grid development and how to identify good grid development strategies. Such strategies should produce solutions that are robust to uncertainties in the energy system over the next decades. Moreover, grid development solutions should also be robust in the sense that grids are designed to be resilient and not vulnerable to component failures.

This project will develop knowledge and methods to enable a socio-economic profitable and robust development of coupled offshore and onshore power grids, against a backdrop of large-scale offshore wind development and a changing onshore energy system. To achieve this, the project will address a series of scientific challenges: One should be able to identify robust strategies for developing coupled offshore and onshore grids. In particular, the project targets knowledge gaps related to interdepencies, interactions and synergies between offshore and onshore grids. Then, one needs to be able to communicate trade-offs between different kinds of costs and benefits and risks to better understand the socio-economic impacts of grid development. One of the key socio-economic impacts of grid development is on the security of electricity supply. It is therefore important to be able to assess the risk to security of supply, including analysing the reliability and resilience of coupled onshore/offshore grids, considering vulnerability and resilience of the coupled offshore-onshore power system (considering the important role of HVDC and offshore wind). Identifying potential vulnerabilities will help ensuring that the future offshore-onshore power grid is developed to be resilient by design. To carry out these analyses one must solve several challenges pertaining to input data: One needs plausible and consistent scenarios and future operating states for power demand and supply, and one needs to consider not only a few typical states but also more extreme states to assess the vulnerabilities of the system. Expected results include algorithms, datasets and reduced grid models that can be made openly available, to allow more transparent analyses by stakeholders and the scientific community. Overall, project results will help inform grid investment decision and will give insight into possible grid development paths towards possible future coupled offshore-onshore grids.