Digital map forecasts Spain’s grid constraints and curtailment hotspots for 2027

Identifying grid capacity and exposure to curtailment is becoming an increasingly important factor in the development of renewable energy and storage projects in Spain.

With this in mind, Barcelona-based eRoots has developed a digital map of the Iberian power grid that brings together data on infrastructure, generation, grid capacity, curtailment, electricity markets and permitting in a single geographic interface.

The system models 8,175 nodes, 8,857 lines, 7,479 substations and 8,995 generators, alongside 1,047 two-winding transformers and 603 loads covering 9,951 postal codes. The map can be used to analyze existing assets and simulate grid scenarios to anticipate conditions expected in 2027.

The aim is to identify where grid capacity is available and where renewable generation is likely to face curtailment before investment decisions are made. A capacity layer allows users to compare generation and storage capacity geographically and access information for individual substations, including connected generation and technology types.

A separate layer focuses on curtailment. Heat maps highlight areas with greater exposure to curtailment, while users can analyze individual generation units and view time-series data for production, forecasts and curtailment.

According to eRoots, uncompensated technical curtailment could reach 3.38 TWh in 2027, equivalent to more than €120 million ($136.3 million) in lost clean-energy revenue based on current captured prices for solar PV electricity.

Economic curtailment represents a further source of lost generation. This occurs when plants reduce or stop production because market prices are insufficient to cover operating costs. Spanish renewable energy association APPA estimates that economic curtailment could exceed 20% of potential renewable generation in 2025, or more than 37,000 GWh. According to the association’s methodology, the unused electricity would have an annual value of more than €1 billion.

Developing new generation capacity also requires capital to be committed during permitting. According to eRoots, each gigawatt under development requires approximately €40 million in financial guarantees, regardless of whether the project is ultimately built. For the 10 GW to 12 GW of new capacity expected to come online in 2027, this would represent more than €400 million in guarantees over a development period of around five years.

The eRoots platform combines these datasets in a spatial interface that allows users to move from regional or grid-node analysis to individual substations, transmission lines, generators and land parcels. It also incorporates information from official gazettes, with 31,797 publications and 18,280 projects indexed, to link grid conditions with the status of project permitting.

The platform is available under several subscription plans. Its Monthly Flex plan costs €1,800 per month and provides access to the base map. An annual subscription costs €1,200 per month, billed annually, and includes curtailment forecasting for one node. Forecasting for additional nodes costs €1,800 per node per year.

The Professional plan costs €29,400 per year and covers analysis of 12 nodes, including access to the base map, while the Enterprise plan costs €44,400 per year and provides unlimited node and scenario coverage. eRoots also offers individual capacity and curtailment studies starting at €10,000 per node.

The platform is designed to bring grid analysis into project investment decisions by assessing not only where connection capacity is available, but also how individual nodes could be exposed to future curtailment as additional generation is connected.