Ciclos combinados: la firmeza que sostiene el verano

This summer, the Spanish electrical system has faced multiple heatwaves, testing its resilience and demanding technologies that can react quickly when needed. National system generation data for July confirms that combined cycle power plants play a decisive role in ensuring continuity of supply and maintaining electrical stability. They supplied nearly 20% of total production, or around 5,500 GWh, and were the main source of generation during most afternoons and evenings, when demand peaks.

Despite the transition to renewable energy, combined cycle plants remain crucial due to the variability of renewable sources like solar and wind. Their flexible power output has been essential in achieving current renewable penetration levels and will continue to allow further increases towards future targets. However, renewable generation is weather-dependent, which can create mismatches with peak consumption times, especially during intense summer heatwaves and cold winters.

In these situations, combined cycle plants' rapid response and immediate availability prove their strategic value, maintaining system stability while incorporating more renewables without compromising supply security. Their ability to supply energy when the system truly needs it is becoming increasingly important as the share of variable technologies grows. While battery storage shows promise, it is still in an early stage and cannot yet provide a short-to-medium term solution.

The National Integrated Energy and Climate Plan (PNIEC) has allocated nearly 26 GW of combined cycle capacity for 2030, recognizing that these plants will remain indispensable for a safe and orderly energy transition. Their importance must be acknowledged in energy planning, but a supportive regulatory framework is equally crucial to ensure their availability when needed. A mere operational capacity figure is not enough; the system must be prepared to mobilize these resources at critical moments.

The recent European Commission's approval of the Spanish electrical system capacity market, in line with EU state aid rules, represents a significant step. However, the design of this market must be done carefully to preserve system balance and accurately reflect each technology's contribution to supply security during critical moments.

Regulatory deadlines, such as the timing of auctions and the definition of firmness coefficients, should not be delayed. The system has already demonstrated the need for these resources; regulatory support is now essential to ensure their strategic role.

Recent operation data from the April 2025 blackout highlight the evidence that energy planning had already recognized: combined cycle plants will continue to be essential for Spain's electrical system in the coming decade. Promptly activating and rigorously designing capacity markets is not slowing down the energy transition, but providing the stability and resilience it requires to continue advancing.