Spain's EUR 17bn grid plan stays inside the peninsula as its interconnection falls to 3.11 per cent

Spain's energy ministry spent the last week of September presenting, region by region, a revised plan for the high-voltage grid. The Secretary of State for Energy, Joan Groizard, put the national figure at more than EUR 17 billion to 2030 and said on 30 September that this was 144 per cent above the EUR 6.964 billion of the plan it replaces. Almost all of that money stays inside the peninsula. On the European Commission's own measure, the share of Spanish installed generating capacity matched by cross-border links fell to 3.11 per cent in 2026, the lowest in the published series. The plan is a careful answer to the problem the April 2025 blackout exposed inside the Iberian system. It does not answer the one at its edge.

What the plan buys

The ministry's figures, published after the public consultation, describe a plan enlarged at almost every line: 193 substations, 17 per cent more than in the initial proposal; 6,706 km of new transmission lines, up 11 per cent; and 8,164 km of existing network to be reinforced, up 6 per cent. Connection positions for distribution-level demand rise 52 per cent to 300, and positions for rail and port electrification rise 75 per cent to 59.

Andalusia takes the largest share — 1,283 km of new lines, 19 substations, ten reactance units and two synchronous compensators, opening 5 GW for new demand, more than 8 GW for wind and solar and 1 GW for storage, with industry accounting for 70 per cent of the new demand. The regulated ceiling was raised first: in September 2025 the government lifted the investment limits, taking the transmission plan to EUR 13.59 billion to 2030, 65 per cent above the 2021-2026 plan, with a minimum of 10 per cent of spending earmarked for grid security, according to Euronews.

The ratio that keeps falling

The Commission's interconnection table is the awkward counterpoint. Spain's level was 4.96 per cent in 2021, 5.35 per cent in 2022, 4.42 per cent in 2023, 4.23 per cent in 2024, 3.62 per cent in 2025 and 3.11 per cent in 2026. Portugal's, measured against Spain, stands at 13.33 per cent. The EU target is at least 15 per cent by 2030, and the Commission notes that nine member states remain below the earlier 10 per cent target set for 2020.

Spain's figure has fallen while Spain builds, because capacity added inside the peninsula is outrunning capacity added across the Pyrenees. One project changes that materially. Inelfe, the joint venture of Red Electrica and RTE, says the Bay of Biscay link will raise exchange capacity between the two countries from 2,800 to 5,000 MW over roughly 400 km, about 300 km of it submarine; its cost was updated to EUR 3.1 billion against an originally planned EUR 1.75 billion, testing is due to begin in mid-2027 and service in 2028. The last addition, the underground link through the eastern Pyrenees, doubled capacity from 1,400 to 2,800 MW and entered service in October 2015. Inelfe presents the new link as a contribution to the 10 and 15 per cent targets, not as delivery of them.

What the blackout actually asked for

The diagnosis of 28 April 2025 points inward, which is part of why the plan does. ENTSO-E published its final report on 20 March 2026; its president, Damian Cortinas, said there was "no single cause" and that the event was "a perfect storm of multiple factors", as Euronews reported. The report found the Iberian system unable to control overvoltage, converter-connected generation disconnecting as voltage rose, and real-time monitoring that did not identify the risk as levels approached critical thresholds. It rejected the claim that dependence on renewables alone caused the collapse. It was the most severe blackout in more than two decades of the interconnected European system, reaching Spain, Portugal and south-western France.

That finding is about devices and procedures, and it is visible in the plan's reactances and synchronous compensators. Red Electrica submitted proposals to the CNMC and the ministry on 13 May 2026 covering incident-analysis monitoring, the scheduling of balancing services and technical constraints, and coordination between transmission and distribution planning. Its parent, Redeia, is committing EUR 6 billion to Red Electrica over 2026-2029, an average of EUR 1.5 billion a year and 70 per cent above the previous plan. On firm capacity, Bloomberg reported on 29 May 2026 that the EU had approved a EUR 9 billion Spanish mechanism to secure electricity supply.

Generation policy moved the same way. By ministerial order published on 14 August 2026 the government extended both Almaraz units to 8 June 2030, from November 2027 and October 2028 under the 2019 closure schedule, after a favourable report from the Nuclear Safety Council on 16 July. Euronews reported that Almaraz supplies around 7 per cent of national electricity production and that after the blackout "the role of nuclear power and the need to keep these plants running returned to the heart of the debate". The rest of the 2019 timetable, ending in 2035, stands.

What is still only a proposal

The EUR 17 billion is a planning proposal presented after the consultation, not an approved instrument; the ministry's own term is "propuesta de planificacion". The same week showed where outward links are in fact being processed, and they are not electrical: on 30 September the ministry opened an accelerated authorisation route for the first segments of Enagas's renewable hydrogen trunk network, which hold European project-of-common-interest status — Onuba in Huelva, Catalina in Teruel and Petronor in Vizcaya, EUR 389 million in all, feeding the H2Med corridor. Those are future molecules. The electrons still have one route north, and it is unfinished.

What to watch

• Whether the Council of Ministers approves the proposal at the figures the ministry presented in late September, and what the CNMC says on it.
• Whether the Bay of Biscay link holds mid-2027 testing and 2028 commissioning.
• Whether the Commission's interconnection figure for Spain stops falling in the next series, or declines again as domestic capacity grows.
• Whether the capacity mechanism approved in May holds its first auction before the 2027 heating season, and whether Almaraz's June 2030 date is treated as final.

Sources

• MITECO — Groizard avanza el resultado de la nueva Propuesta de planificacion de electricidad con horizonte 2030 en Andalucia
• MITECO — Groizard avanza el resultado de la nueva Propuesta de planificacion de electricidad con horizonte 2030 en Galicia
• MITECO — El MITECO tramita los primeros segmentos de la Red troncal de hidrogeno
• European Commission — Electricity interconnection targets
• Inelfe — The electricity interconnection across the Biscay Gulf
• Red Electrica — Spain-France underground electricity interconnection
• Redeia — Strategic Plan 2026-2029
• Red Electrica — Red Electrica unveils a new suite of measures to further strengthen the Spanish electricity system
• Euronews — 'Perfect storm' of multiple factors behind 2025 Iberia power blackout, experts say
• Euronews — Spain extends Almaraz nuclear plant operations to 2030, delaying closure by three years
• Euronews — El Gobierno amplia el limite de inversion en la red electrica hasta 2030
• Bloomberg — EU Approves EUR 9 Billion Spanish Plan to Boost Electricity Supply Security