Solar thermal technology has gained prominence within the Spanish energy system. In recent years, it has stood out not only for its renewable energy contribution but also for its stabilizing role in the national electricity grid. Given recent episodes that have tested the security of the electricity supply, more and more people are pointing to the need to strengthen the presence of solar thermal power in the energy mix as a solution to address the challenges of a grid dominated by intermittent sources.
In a context where the ecological transition is progressing at a good pace and there is a call to further diversify energy sources, solar thermal power is consolidating as a strategic resource due to its ability to operate synchronously and provide long-term thermal storage, essential qualities in scenarios of high demand or unexpected incidents in the system.
The importance of solar thermal power for the stability of the electrical system
According to data from the Committee in charge of analyzing the recent electricity crisis, it has become clear that The contribution of solar thermal power plants helps maintain critical parameters such as frequency and voltage, thanks to its rotational inertia and regulation capabilities. These technical attributes are not offered by other renewable energy sources such as photovoltaics or wind power, as they operate non-synchronously and are more dependent on weather conditions.
Óscar Balseiro, general secretary of the Protermosolar association, emphasizes that in a network where intermittent technologies predominate Solar thermal power guarantees strength and safety, offering essential operational supportIn addition, its thermal storage systems allow solar energy to be stored during the day and released at night, providing flexibility and reducing vulnerability at critical times.
Current situation and growth potential
Spain currently has 49 solar thermal plants totaling 2.300 megawatts of power, many of them equipped with molten salt tanks capable of storing energy for up to nine hours. During 2024, 25% of solar thermal generation was fed into the grid at night, covering demand in periods where other renewables, such as solar photovoltaic and wind, cannot operate.
However, only 40% of the installed solar thermal capacity currently has storage, which, according to several experts, opens up immediate room for improvement to expand it and strengthen resilience to future energy crises.
The sector itself puts on the table that Existing solar thermal plants allow for rapid increases in storage capacity, provided that administrative obstacles are removed and investment in the technological improvement of these facilities is encouraged.
Government measures and sector recommendations
Among the recommendations highlighted by both the technical report and those responsible for the Executive, the following is included: Increased energy storage and the review of regulatory standards that affect adjustment services and technical restrictions. These factors are crucial for solar thermal power to fully realize its potential.
Furthermore, the so-called Electricity Planning 2025-2030 places special emphasis on prioritize industrial consumption, a field where solar thermal energy is already facilitating decarbonization. This translates into installations in production plants across various sectors, supported by initiatives such as the recent publication of the Concentrated Solar Thermal Energy Guide for Industrial Processes, developed by Protermosolar and the IDAE.
Competitive advantages and future challenges
Solar thermal power is currently The only renewable source that combines synchronous operation and long-term thermal storage, which allows it to offer unique network support services that are difficult to replace with other technologies.
The government plans to soon approve a package of reforms to strengthen the electricity system, which could consolidate Spain's global leadership position in solar thermal energy or, conversely, mean the loss of two decades of progress if opportunities are missed.
It emphasizes the urgency of adapting regulations and removing obstacles to expanding the capacity of these plants, strengthening their strategic role and ensuring a solid and stable energy transition.
Everything indicates that expanding the operation of existing plants, along with promoting new projects included in the National Integrated Energy and Climate Plan, will consolidate solar thermal energy as one of the pillars of Spain's future energy mix.
Solar thermal energy is consolidating its position as a key technology for addressing the challenges of the current energy landscape: it combines reliability, storage, and decarbonization, making a decisive contribution to both the security of supply and the sustainability of the Spanish electricity system.