Lately, everything is being analyzed in a nuclear context. Partly because the impending closure of the Almaraz nuclear plant has revived political debate, paradoxically, without its owners (Iberdrola and Endesa) or the Government requesting a reversal of the dismantling plan. Also, because warnings are increasing about the second-round effects that the blackout will bring. With just a few days apart, the International Energy Agency (IEA) and Enagás, the company managing Spain's major gas pipelines, have warned that the closure of nuclear plants will increase Spain's dependency on natural gas in critical moments, when there are peaks in electricity demand and renewables are insufficient.
"The nuclear disconnection will lead to the loss of a generation based that will make combined cycles [facilities burning gas to generate electricity] play an additional role in providing that generation capacity," predicted Enagás CEO, Arturo Gonzalo Aizpiri, during the group's annual results presentation.
In detail, the executive estimated that the electricity demand peaks that gas will have to supply could increase by 22% by the end of the decade compared to 2024 values. If compared to the historical average recorded since the winter of 2017-2018, the demand for natural gas to meet electricity consumption peaks will increase by 70% by 2030, as reported by the company in one of the documents sent to the market yesterday.
"Demand peaks will increase because renewable energies, which will be the basis of our electrical system, are intermittent," Aizpiri noted, recalling the record contribution of cycles last December due to the phenomenon known as the 'dark calm' - or Dunkelflaute in German - the simultaneous absence of wind and sun, and therefore renewable energy, which has increased gas consumption in Europe this winter.
This vulnerability is particularly relevant considering that according to the National Energy and Climate Plan (PNIEC) for 2030, updated by the Ministry of Ecological Transition in September, electricity demand will increase by 34% in Spain by 2030, with 84% of the country's electricity consumption expected to come from renewable sources. Among the new consumption drivers, Aizpiri highlighted the arrival of data centers.
The Ministry led by Sara Aagesen submitted the PNIEC projections to Red Eléctrica, the state-owned company responsible for managing the national electrical system, ensuring that electricity demand and supply match every second, every day of the year. In its analysis, the company stated that "demand coverage is guaranteed," but by removing nuclear power from the equation, it also warned that any deviation in the deployment of green generation or storage could compromise "the desired level of supply security." Storage is the solution the Government relies on to provide the system with the robustness previously provided by manageable energies (coal, nuclear, or natural gas).
As renewables have gained weight in the system, they have replaced cycles in the electricity mix due to their lower price, and in turn, cycles have reduced their operating hours. Since the pandemic, they have not exceeded 2,000 annual hours, except for 2022 (2,466). In 2024, they operated for 1,185 hours. The latest PNIEC reduces the forecasted annual operating hours of cycles to 800 by 2030. However, the peninsular fleet of combined cycles has simultaneously increased the number of times they have had to start their machines since the pandemic: from 4,175 starts in 2021 to over 8,000 in 2024.
This evolution reflects the changing role that gas has assumed in the national electrical system. First, due to the dismantling of coal plants and soon, due to the nuclear shutdown; gas is expected to become the safety mechanism that will prevent blackouts when required by Red Eléctrica. This is why the Government is finalizing a capacity market model, that is, regulated payments to ensure coverage during system stress moments.
The Government's roadmap does not warn that the nuclear shutdown will lead to a greater dependency on natural gas for electricity generation at critical moments, but it does keep the installed capacity of cycles unchanged by the end of the decade. While the Government plans to reduce the planned nuclear capacity from the current almost 7.4 gigawatts (GW) to 3 GW by 2030, the capacity of cycles remains unchanged at 26.6 GW.
A few days ago, in its latest global report, the International Energy Agency (IEA) also referred to the Spanish nuclear closure schedule. It pointed out that "unless there is an increase in storage, the electrical system's dependency on combined cycles will increase." The international organization noted that our country lacks gas fields, so "an increase in the consumption of this fossil energy source will harm the industry's competitiveness."
In this regard, technical sources explain that although the flexibility of cycles will be "very important" for Spain in the short term, nuclear plants will not be massively replaced by natural gas but by renewables. "The cycles will cover the peaks, yes, but will operate very little the rest of the time, so there will be no additional CO2 emissions due to the nuclear shutdown," they reflect.