Spain is a country with high hydroelectric potential , developed over more than 100 years. Today, our hydroelectric generation system is one of the most efficient in the world, taking advantage of the country's topography and the construction of numerous dams. This positions hydroelectric power as one of the most established and mature renewable energy sources within Spain's energy mix.
Hydroelectric power
Hydroelectric power in Spain is mainly classified into two types of facilities for its use: run-of-river power plants and dam-foot power plants.
Run-of-river power plants capture part of the flow of a river and direct it towards the power plant, where the water is turbined to generate electricity and then returned to the riverbed. These plants, usually small-scale, have capacities of less than 5 MW and account for 75% of the hydroelectric market in Spain. They also include "irrigation canal power plants", which take advantage of the difference in level of irrigation canals to generate electricity.
On the other hand, run-of-river hydroelectric plants are facilities that regulate water flow by constructing dams. These plants are typically more powerful, with capacities exceeding 5 MW, representing approximately 20% of the market. Run-of-river plants include a special type called pumped- storage hydroelectric plants , designed to store water in an upper reservoir and generate electricity during periods of low demand. During periods of high demand, water is released from the reservoir to generate electricity, achieving high energy efficiency.
Installed capacity in Spain
Currently, the total capacity of reservoirs in Spain is 55.000 cubic hectometers (hm³ ) , of which 40% corresponds to hydroelectric reservoirs, placing the country among the leaders in Europe and the world. Spanish hydroelectric infrastructure has an installed capacity of 17.792 MW, representing 19,5% of the country's total installed capacity.
This enormous capacity is distributed across more than 800 hydroelectric power plants of varying sizes. Among the largest are 20 plants with an installed capacity exceeding 200 MW, which together account for 50% of the total hydroelectric capacity. There are also smaller dams with capacities below 20 MW, scattered throughout Spain.
The autonomous communities with the highest installed capacity are Catalonia, Galicia , and Castile and León , due to their high concentration of water resources. These areas, with their topography and water flow, are ideal for hydroelectric power generation.
Decrease in hydroelectric energy in the energy mix
Throughout history, hydroelectric energy has played a fundamental role in the production of electricity in Spain. However, in recent years there has been a decrease in its share in the energy mix due to the incorporation of other renewable energy sources, such as wind and solar energy. Despite this decline, it remains one of the most productive renewable energies.
In figures, in 2014, hydroelectric energy contributed 15,5% of total production, generating 35.860 GWh. Although it was a good year in terms of hydroelectricity, it was behind other sources such as nuclear (22%) and wind (20,3%). Despite its more moderate contribution, hydroelectric energy continues to play a crucial role, especially in years with good rainfall.
Technological development
In recent decades, technological advancements have allowed small-scale hydropower (plants with less than 10 MW of installed capacity) to become a competitive option in the electricity market. These plants can be run-of-river or dam-based and have the advantage of supplying electricity to more isolated areas without requiring extensive infrastructure.
In addition, microturbines with power outputs of less than 10 kW are under development , capable of generating electricity in hard-to-reach areas. These turbines are highly efficient and do not require large waterfalls or expensive infrastructure, making them a particularly useful solution for rural or isolated areas.
The future of hydroelectric energy in Spain
According to industry projections, hydroelectric power is expected to continue growing at an annual rate of between 40 and 60 MW in Spain. However, the sustainable economic potential is in the range of more than 1 GW, reflecting the growth potential of this technology.
In this regard, the most promising proposals focus on the modernization and rehabilitation of existing plants, to improve their performance. Similarly, there is a commitment to pumped storage plants, which can store energy and release it when demand increases, contributing to the stability of the electricity grid.
Hydroelectric power has a centuries-old tradition in Spain, and although its role in the energy mix has diminished, its relevance remains fundamental. With the development of new technologies such as microturbines and reversible power plants, and the expected increase in installed capacity, this renewable energy source has a promising future. The combination of the use of existing water resources and the modernization of facilities will help Spain maintain its position as a leader in hydroelectric energy.