North Sea Offshore Grid Research Articles

Evaluating the offshore wind business case and green hydrogen production: A case study of a future North Sea Offshore Grid

The European Union aims to increase its climate ambition and achieve climate neutrality by 2050. This necessitates expanding offshore wind energy and green hydrogen production, especially for hard-to-abate industrial sectors. A study examines the impact of green hydrogen on offshore wind projects, specifically focusing on a potential future North Sea offshore grid. The study utilizes data from the TYNDP 2020 Global Ambition scenario 2040, considering several European countries. It aims to assess new transmission and generation capacity utilization and understand the influencing factors. The findings show that incorporating green hydrogen production increases offshore wind utilization and capture prices. The study estimates that by 2040, the levelized cost of hydrogen could potentially decrease to €1.2-1.6/kg H2, assuming low-cost electricity supply and declining capital costs of electrolysers. These results demonstrate the potential benefits and cost reductions of integrating green hydrogen production into North Sea offshore wind projects.

Going offshore or not: Where to generate hydrogen in future integrated energy systems?

Hydrogen can be key in the energy system transition. We investigate the role of offshore hydrogen generation in a future integrated energy system. By performing energy system optimisation in a model application of the Northern-central European energy system and the North Sea offshore grid towards 2050, we find that offshore hydrogen generation may likely only play a limited role, and that offshore wind energy has higher value when sent to shore in the form of electricity. Forcing all hydrogen generation offshore would lead to increased energy system costs. Under the assumed scenario conditions, which result in deep decarbonisatiton of the energy system towards 2050, hydrogen generation – both onshore and offshore – follows solar PV generation patterns. Combined with hydrogen storage, this is the most cost-effective solution to satisfy future hydrogen demand. Overall, we find that the role of future offshore hydrogen generation should not simply be derived from minimising costs for the offshore sub-system, but by also considering the economic value that such generation would create for the whole integrated energy system. We find as a no-regret option to enable and promote the integration of offshore wind in onshore energy markets via electrical connections.

Benefits of an integrated power and hydrogen offshore grid in a net‐zero North Sea energy system

The North Sea Offshore Grid concept has been envisioned as a promising alternative to: 1) ease the integration of offshore wind and onshore energy systems, and 2) increase the cross-border capacity between the North Sea region countries at low cost. In this paper we explore the techno-economic benefits of the North Sea Offshore Grid using two case studies: a power-based offshore grid, where only investments in power assets are allowed (i.e. offshore wind, HVDC/HVAC interconnectors); and a power-and-hydrogen offshore grid, where investments in offshore hydrogen assets are also permitted (i.e. offshore electrolysers, new hydrogen pipelines and retrofitted natural gas pipelines). In this paper we present a novel methodology, in which extensive offshore spatial data is analysed to define meaningful regions via data clustering. These regions are incorporated to the Integrated Energy System Analysis for the North Sea region (IESA-NS) model. In this optimization model, the scenarios are run without any specific technology ban and under open optimization. The scenario results show that the deployment of an offshore grid provides relevant cost savings, ranging from 1% to 4.1% of relative cost decrease (2.3 bn € to 8.7 bn €) in the power-based, and ranging from 2.8% to 7% of relative cost decrease (6 bn € to 14.9 bn €) in the power-and-hydrogen based. In the most extreme scenario an offshore grid permits to integrate 283 GW of HVDC connected offshore wind and 196 GW of HVDC meshed interconnectors. Even in the most conservative scenario the offshore grid integrates 59 GW of HVDC connected offshore wind capacity and 92 GW of HVDC meshed interconnectors. When allowed, the deployment of offshore electrolysis is considerable, ranging from 61 GW to 96 GW, with capacity factors of around 30%.

The Value of Sector Coupling for the Development of Offshore Power Grids

Offshore grids can play key roles in the transition of energy systems toward sustainability. Although they require extensive infrastructure investments, they allow for the exploitation of additional resources and may be important in providing for part of the increasing electricity demands driven by sector coupling. This paper quantifies the socioeconomic value of offshore grids and identifies their major drivers, performing energy system optimization in a model application of the northern–central European energy system and the North Sea offshore grid towards 2050. The increasing wake loss with the sizes of hub-connected wind farms is integrated in the modeling. We find that without sector coupling no offshore grid may develop, and that the higher the level of sector coupling, the higher the value of offshore grids. Therefore, it can be strongly stated that offshore grid infrastructure development should not be discussed as a separate political topic, but seen in connection to sector coupling.

The Influence of Large-Scale Wind Farm Wake Losses and Sector Coupling on the Development of Offshore Grids

Offshore grids can have a key role in the transition of the energy system to sustainability. Although they require extensive infrastructure investments, they open up for the exploitation of additional resources and may be important to provide for part of the increasing electricity demand driven by sector coupling. This paper quantifies the socio-economic value of offshore grids and identifies their major drivers, performing energy system optimization in a model application of the Northern-central European energy system and the North Sea offshore grid towards 2050. The increasing wake loss with the size of hub-connected wind farms is integrated in the modelling. We find that without sector coupling no offshore grid may develop, and that the higher the level of sector coupling, the higher the value of offshore grids. Considering the influence of increasing wake losses with the size of hub-connected wind farms is especially relevant with higher level of sector coupling, leading to a more spread distribution of hub-connected wind farms, and to an improved representation of the available wind generation in the hubs. Therefore, it can be strongly stated that offshore grid infrastructure development should not be discussed as a separate political topic, but seen in connection to sector coupling.

North Sea offshore grid development: combined optimisation of grid and generation investments towards 2050

The North Sea region offers large amounts of investable offshore wind generation and several interconnection lines are located in the area, with more planned. Optimal transmission and generation investments are modelled in the region towards 2050. A project-based scenario, where each offshore wind power plant is connected individually, is first analysed. Then, an integrated offshore grid is modelled to investigate the viability of connecting future transmission and offshore wind generation investments. These two scenarios are then compared. It is shown that going towards an integrated solution can increase offshore wind investments by several GWs, with Germany seeing the biggest difference between the two scenarios. It is shown that the integrated solution leads to overall cost minimisation and shows somewhat higher variable renewable energy generation by 2050 compared to the project-based scenario.

The integrated offshore grid in Europe: Exploring challenges for regional energy governance

The deployment of offshore wind and power transmission in the European North Sea is accelerating. Stakeholders advocate regional governance for the European grid expansion, which may evolve into a pan-European governance and is key to developing integrated, hybrid offshore projects. However, such projects are still scarce. We thus analyze the governance of the North Sea offshore grid expansion using the dimensions of level, implementation obligation, and implementation discretion. Our exploratory approach identifies five challenges. The challenges relate to 1) the interaction of the European and regional levels; 2) the interaction of the national and regional levels; 3) the participation of non-European Union countries; 4) the dependence of regional planning on national development plans, which consider national interests; and 5) the interaction of cost allocation and European financing for Projects of Common Interest. The recent Clean Energy Package proposal extensively reforms the regulation of the European power system. The Package is part of the Energy Union strategy and focuses on the energy and climate policies’ governance and the power system operation. Thus, regional governance of offshore expansion is largely unaltered, and our identified challenges remain unaddressed.

A Mechanism for Allocating Benefits and Costs from Transmission Interconnections under Cooperation: A Case Study of the North Sea Offshore Grid

We propose a generic mechanism for allocating the benefits and costs that result from the development of international transmission interconnections under a cooperative agreement. The mechanism is based on a planning model that considers generation investments as a response to transmission developments, and the Shapley Value from cooperative game theory. This method provides a unique allocation of benefits and costs considering each country’s average incremental contribution to the cooperative agreement. The allocation satisfies an axiomatic definition of fairness. We demonstrate our results for three planned transmission interconnections in the North Sea and show that the proposed mechanism can be used as a basis for defining a set of Power Purchase Agreements among countries.

Economic and environmental benefits from integrated power grid infrastructure designs in the North Sea

The North Sea Offshore Grid (NSOG) is considered an important contributor towards large-scale integration of renewables and electricity market coupling. Different typologies have been studied for such a multinational power grid, ranging from radial point-to-point connections to more integrated meshed typologies. An artificial island enables a high level of integration of both offshore wind power and transnational trade due to economies of scale. This paper present multiple case studies of the Power Link Island (PLI) which is visioned by TenneT in the Doggerbank area. Our results demonstrate that the capabilities of such an island could add significant value to the system as a result of more efficient use of geographically spread, cost-efficient resources. However, depending on the future level of grid integration and generation mix, the added value of a PLI varies between e0.15bn to e20bn. Consequently, this could result in 18% more efficient utilization of renewable resources, primarily offshore wind, and significant reductions of CO2 emissions.

Expansion planning of the North Sea offshore grid: Simulation of integrated governance constraints

The development of offshore transmission and wind power generation in the North Sea of Europe is advancing fast, but there are significant barriers to an integrated offshore grid in the region. This offshore grid is a multi-level, multi-actor system requiring a governance decision-making approach, but there is currently no proven governance framework for it, or for the expansion planning of the European power system in general. In addition, existing offshore expansion planning models do not endogenously include governance considerations, such as country vetoes to integrated lines. We develop a myopic Mixed-Integer Linear Programming model of offshore generation and transmission expansion planning to study the effect of integrated governance constraints. These constraints limit investments in integrated lines: non-conventional lines linking offshore wind farms to other countries or to other farms. Each constraint affects the system (including the main transmission corridors), transmission technologies and welfare distribution differently. We apply our model to a long-term case study of the 2030–2050 offshore expansion pathways using data from the e-Highway2050 project. Results confirm that the offshore grid is beneficial to society. Integrated governance constraints induce a modest loss of social welfare, but do not change significantly the existing welfare distribution asymmetry between countries and actor groups. They do strongly affect the interaction of line technologies and types (conventional or integrated), so the impact of the integrated governance constraints is more visible on the grid topology than on welfare levels and distribution. We highlight the need to consider technology and type interactions in expansion planning, especially between multiterminal HVDC and integrated transmission lines. Also, an offshore governance framework should address the use of multiterminal HVDC in a non-integrated grid, but this is a second-best option compared to an integrated grid.

Towards a fully integrated North Sea offshore grid: An engineering‐economic assessment of a power link island

An increasing share of variable power feed‐in is expected in the next decades in the European power system, with a particularly high offshore wind potential in the North Sea region. This demands more temporal‐ and spatial flexibility in the system, an adequate grid infrastructure can provide both. This study presents an engineering‐economic approach evaluating the impact of novel infrastructure designs towards a fully integrated North Sea offshore grid, including TenneT’s vision of a power link island (PLI). A PLI is an artificial island for transnational power exchange and distribution of offshore wind resources. We introduce the concept and evaluate the economic benefits and system implications under three different case studies incorporating 2030 scenarios from European Network of Transmission System Operators. The results demonstrate system cost savings up to 15.8% when comparing a fully integrated PLI solution with traditional, radial typologies. The PLI did in general result in more efficient system dispatch of wind resources, where the involvement from Norway, Great Britain, and Germany occurred most frequently in terms of grid reinforcements and expansions.This article is categorized under: Wind Power > Systems and Infrastructure Energy Infrastructure > Systems and Infrastructure Energy Systems Economics > Systems and Infrastructure

A generic framework for power system flexibility analysis using cooperative game theory

Electricity grid infrastructures provides valuable flexibility in power systems with high shares of variable supply due to its ability to distribute low-cost supply to load centers (spatial), in addition to interlinking a variety of supply and demand characteristics that potentially offset each others negative impact on system balance (temporal). In this paper, we present a framework to investigate the benefits of alternative flexibility providers, such as fast-ramping gas turbines, hydropower and demand side management, by using a generation and transmission capacity expansion planning model. We demonstrate our findings with a multinational case study of the North Sea Offshore Grid with an infrastructure typology from year 2016 and operational data for year 2030 – considering a range of renewable capacity levels spanning from 0% to 100%. First, we show how different flexibility providers are allocated geographically by the model. Second, operational cost savings are quantified per incremental unit of flexible capacity. Finally, we present a way to rank different flexibility providers by considering their marginal contribution to aggregate cost savings, reduced CO2 emissions, and increased utilization of renewable energy sources in the system. The Shapley Value from cooperative game theory allows us to assess the latter benefits accounting for all possible sequences of technology deployment, in contrast to traditional approaches. The presented framework could help to gain insights for energy policy designs or risk assessments.

Multistage grid investments incorporating uncertainty in offshore wind development

Representation of uncertainty in transmission expansion planning (TEP) models has become increasingly important as many power systems are exposed to significant technological changes induced by top-down climate and energy targets. The objective with this paper is to incorporate uncertainty regarding future offshore wind deployment and allow two investment stages for grid expansion, where the second stage provides valuable flexibility for a system planner. A stochastic two-stage mixed-integer linear program is used for this purpose applied to a case study of the North Sea Offshore Grid (NSOG). With the given data and assumptions, we show that the system planner can gain maximum €1.72 bn (0.40 %) in terms of cost savings under perfect information about the wind deployment. The expected cost savings for a more forward-looking system planner using a stochastic program is €22.30 m (0.0052 %), in comparison with the best deterministic approach. Moreover, we show that if the planner can postpone its investment decision with five years an expected cost saving of €22.41 m would arise.

Marine wind energy and the North Sea Offshore Grid Initiative: A Multi-Level Perspective on a stalled technology transition?

Building electricity grids out to sea implies a radical transformation of grid topologies. In time, a marine super-grid is conceivable. If growing numbers of subsea electricity cables are meshed with marine renewable, a ‘greening’ of such grids is also possible. Based on interview research, this paper examines one such ambitious proposal: the Northern Seas Countries Offshore Grid Initiative (NSCOGI). The Multi-Level Perspective (MLP) on technology transitions is used to evaluate progress to date. Obstacles uncovered include competing and still immature grid technology niches. There is only equivocal support from key actors within the relevant socio-technical electricity regime. National grid Transmission System Operators (TSOs) appear more interested in subsea cables to trade electricity rather than enhancing marine renewables. While the EU might be assumed to be a vital actor to support a North Sea Grid, it has only limited influence. National policy insiders and decisions matter more. This paper stresses the residual importance of the national level for offshore wind and electricity grids. A marine super-grid wired up with offshore wind-farms throughout the North Sea, is both more tentative in its emergence, but also ambiguous in its support for offshore wind.

North Sea offshore network and energy storage for large scale integration of renewables

This review investigates different aspects of the realization of a North Sea offshore grid. The North Sea region has several characteristics that make large-scale integration of renewable energy sources attractive, such as large wind resources and huge hydro reservoirs in the North. A meshed offshore grid with underwater storage can contribute to facilitate sufficient flexibility in the system. The technical review reveals some aspects that need more research, particularly regarding the protection schemes. Furthermore, offshore storage solutions are under development. However, most other aspects are covered by readily available solutions. The greatest challenges seem to lie within standardization, cost-benefit sharing and harmonization of regulatory regimes of the surrounding countries. Nevertheless, several studies have shown highly promising economic benefits of establishing an offshore grid in the North Sea compared to traditional planning of point-to-point connections only.

Analysis: Europe could lose renewables lead

The EU economic recovery plan sets aside over euro890m for key strategic interconnections in the power grid (see 'Eire-UK power link to go ahead', p4) and euro565m for offshore wind that includes the initiation of the first stage of a North Sea offshore grid. These measures will help unlock the largest European indigenous energy resource and stimulate Europe's lagging economies.