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 topography of the territory and the construction of numerous dams. This places hydroelectric energy as one of the most consolidated and mature renewable sources within the Spanish energy mix.
Hydroelectric power
Hydroelectric energy in Spain is mainly classified into two types of facilities for its use: run-of-river plants and dam foot power stations.
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.
Furthermore, the dam foot power stations Dam-based power plants are facilities that regulate the flow of water by building dams. These facilities are usually more powerful, with capacities greater than 5 MW, representing about 20% of the market. Dam-based power plants include a special type called reversible power plants or pumped storage, designed to store water in an upper reservoir by using 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 the reservoirs in Spain is 55.000 cubic hectometres (hm3), of which 40% corresponds to hydroelectric reservoirs, placing the country among the most prominent in Europe and the world. Spain's hydroelectric infrastructure represents an installed capacity of 17.792 MW, which represents 19,5% of the total installed capacity in the country.
This enormous capacity is distributed in more than 800 hydroelectric plants of different sizes. Among the largest, there are 20 plants with an installed capacity of more than 200 MW, which together account for 50% of the total hydroelectric capacity. There are also small dams with power less than 20 MW, spread throughout the Spanish territory.
The autonomous communities with the greatest installed power are Catalonia, Galicia y Castilla y Leon, due to their high concentration of water resources. These areas, with their topography and water flow, are ideal for hydroelectric 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 development has allowed the mini hydro power (those plants with less than 10 MW of installed capacity) become a competitive option within the electricity market. This type of plant can be run-of-river or dam-footed and has the advantage of being able to supply electricity in more isolated areas, without the need for large infrastructures.
In addition, they are in development microturbines with powers of less than 10 kW, 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 It is in the range of more than 1 GW, reflecting the room for growth that this technology still has.
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.