As the energy system becomes increasingly renewable, electrified and decentralised, each part of the power grid and its operators play a distinct role, involving different stakeholders and policy processes.
While much of this transformation is taking place at the lower voltage levels managed by DSOs, TSO activities are also growing in importance and complexity. TSOs must balance regional variations in supply and demand and integrate an increasingly diverse electricity generation mix, all while continuing to ensure secure and continuous supply. Active cooperation between TSOs and DSOs in both planning and operation of power grids is crucial to integrate new technologies efficiently across voltage levels.
Insights from grid plans
Grid development plans by Europe’s TSOs provide the clearest window into the current status and outlook of countries’ internal transmission networks. In line with Directive (EU) 2019/944 for the electricity market, TSOs publish their ten-year grid plans approximately every two years, setting out the actions necessary to ensure security of supply, efficiency and achievement of decarbonisation targets while keeping costs low. The plans detail the main transmission infrastructure that needs to be built or upgraded over the next ten years, outlining ongoing and new investments. This is a separate process to the development of the Ten-Year Network Development Plan (TYNDP) undertaken by the European Network of TSOs for electricity which focuses exclusively on cross-border transmission lines.
Grids must move in step with renewable generation and clean demand-side technologies in order to deliver the benefits of the energy transition to consumers. The grid plans from TSOs provide valuable insight into future alignment. Energy supply and demand scenarios lie at the core of the grid plans, with the need to expand or upgrade infrastructure highly dependent on which forecasts are explored. To assess how these match up to the current trajectory of Europe’s energy transition, our analysis benchmarks these scenarios against the latest national energy targets and recent market outlooks for wind and solar. The degree of alignment provides a high-level indication of the preparedness of national transmission grids to accommodate the envisioned changes in the energy system necessary to achieve policy goals and facilitate the integration of accelerating renewable deployment.
Given the uncertainties that come with a minimum ten-year outlook, TSOs often incorporate multiple scenarios to represent a range of possible futures for electricity demand and generation patterns. The infrastructural needs assessment, however, is usually based on one specific scenario — this is the scenario we use in our analysis. In the few cases where the needs assessment is based on more than one scenario, the full range of scenarios is used.
Details of the grid plans and energy scenarios examined in this report can be downloaded here, alongside all of the data presented.
Grid plans misaligned with national policy targets
Analysis of grid plans shows that planned transmission grid developments may be insufficient to cater for the renewable uptake that is necessary to achieve energy policy targets. The energy scenarios in the latest grid plans from European TSOs show a high degree of misalignment with current policy targets in certain countries. This is particularly evident in the foreseen installed capacity of wind and solar in 2030. Since it takes far longer to increase grid capacity than it does to deploy wind and solar projects, grids may not be prepared to meet the scale of future increases.
Planned wind and solar capacities are in some cases misaligned with targets
Close alignment with national wind and solar targets should be expected in TSO grid plans, since national legislation related to grid planning often requires TSOs to abide by existing energy policies targets when preparing their plans. However, analysis shows that this is not always the case, with some plans significantly undershooting the national targets.
Wind and solar capacities from the 26 grid plans with adequate data available were compared to their respective 2030 country targets. Of these, ten use scenarios with lower ambition than targets. Among the rest, 13 grid plans were found to be well aligned, and four use more ambitious scenarios.
Of the ten of 26 grid plans that are based on scenarios where the combined capacity of wind and solar is lower than established national policy; the total difference is 65 GW. This is equivalent to about 8% of the total capacity targeted by these countries. While that may not seem significant at a pan-European level, the divergence at national level in certain countries is concerning. For instance, Bulgaria’s grid development plan assumes 4.1 GW wind and solar in 2030 but the country’s policy target is more than 11 GW, a difference of 63%.
When TSOs’ assessments of future infrastructure needs are based on under-ambitious scenarios, it is likely that new investments necessary to support policy targets will be overlooked and their development delayed. This means that, instead of playing an enabling role, transmission grids in a number of countries risk being unprepared to support the wind and solar roll-out expected by national policy, creating a physical barrier to the transition.
However, this is not universally the case. The four plans based on scenarios with higher capacities for wind and solar include Croatia, Denmark, Finland, and the Netherlands. The scenarios used by most of these TSOs are significantly more ambitious than existing targets, ranging from 50% higher for Denmark to 200% higher for Finland.
Across these four countries, the grid plans are preparing for 81 GW more wind and solar than national policy targets. This is a sensible approach that better prepares transmission networks to accommodate potential future step ups in national ambition levels. Indeed, the Finnish TSO notes its scenarios tend towards more positive outcomes as scenarios limited in ambition will not challenge Finland to prepare for the energy transition, but could only guide it to resolve short-term challenges. These more ambitious scenarios also better reflect the accelerated state of the energy transition, such as in the case of the wind and solar capacities used by the Dutch and Croat TSOs which are similar to the market outlooks for these technologies.