A grid map of Spain puts uncompensated curtailment at 3.38 TWh in 2027
Victoria Shinder1 min readBarcelona-based eRoots has built a digital map of the Iberian power grid that combines network, generation, market and permitting data to show where connection capacity is available in Spain and where renewable output is likely to be curtailed, pv magazine reports. The model covers 8,175 nodes, 8,857 lines, 7,479 substations, 8,995 generators, 1,047 two-winding transformers and 603 loads across 9,951 postal codes, and simulates the conditions expected in 2027.
A capacity layer compares generation and storage capacity geographically and shows, substation by substation, what is connected and which technologies. A separate curtailment layer uses heat maps to mark exposed areas, with time series of production, forecasts and curtailment for individual plants.
eRoots estimates that uncompensated technical curtailment, output the grid cannot take and for which plants are not paid, could reach 3.38 TWh in 2027, which it values at more than €120 million of lost revenue at current captured prices for solar power. Economic curtailment comes on top: plants stopping because market prices do not cover costs. The Spanish renewables association APPA estimates it could exceed 20% of potential renewable generation in 2025, more than 37,000 GWh.
What it means
In a market where the binding constraint is the grid rather than the panel, where a project connects decides its revenue as much as what it costs. Tools that model curtailment by node move that question to before the investment decision; the figures are one firm's model, and their value is in comparing sites, not in the national total.