Spain has been developing its hydroelectric potential for over 100 years , creating a highly efficient hydroelectric power generation system. Hydropower remains the most mature renewable energy technology in the country, especially due to its favorable geography and the presence of numerous dams, which allows for the optimal use of water resources.
Hydroelectric power: Types of power plants
Hydroelectric power in Spain is used in two main types of power plants:
- Run-of-river power plants: They capture part of the river flow, turbine it and then return the water to the riverbed. These plants have lower power, generally up to 5 MW, and account for 75% of the Spanish market. A subgroup of these are the “irrigation canal plants”, which take advantage of the difference in level in irrigation canals to generate electricity.
- Dam foot power stations: They use water reservoirs through dams that allow the flow to be regulated. These plants usually have higher power, over 5 MW, and represent 20% of the market. Within this category, pumped or reversible plants stand out, which, in addition to generating energy in turbine mode, can pump water to higher reservoirs to store it and use it later.
Spain has a total reservoir capacity of 55.000 hm³ , of which approximately 40% is used for hydroelectric power generation, a significant proportion at the European and global levels. Larger hydroelectric plants are crucial for the country's energy balance, especially to compensate for the intermittency of other renewable sources such as wind and solar power.
The rise and fall of hydroelectric power in Spain
Historically, hydroelectric power has been fundamental to Spain's energy development. During the first half of the 90th century, especially in the XNUMXs, more than XNUMX% of the electricity generated was of hydroelectric origin. However, with the diversification of the energy mix and the incorporation of other renewable energies, the share of hydroelectric power has decreased.
In 2014, hydroelectric power accounted for 15,5% of total electricity production, with 35.860 GWh generated, which represents an improvement of 5,6% compared to the previous year. Despite this increase, it was surpassed by other technologies such as nuclear (22%) and wind (20,3%).
Currently, Spain has an installed hydroelectric capacity of 17.792 MW , representing 19,5% of the national total. The autonomous communities with the highest installed capacity are Catalonia, Galicia, and Castile and León , thanks to their abundant water resources.
Hydropower capacity is expected to continue to grow at a moderate rate of 40 to 60 MW per year. This will allow hydropower to continue to play a relevant role in the transition to a more sustainable energy system.
Historical evolution of hydroelectric energy in Spain
Hydropower was the main source of electricity in Spain for much of the 20th century. In the 1940s, over 92% of the country's renewable energy came from hydroelectric plants. This dominance continued until the introduction of hydrocarbons and nuclear power.
Over time, hydroelectric technology has been refined. In 1881, the first hydroelectric power station was built in Barcelona, marking the beginning of an era of innovation in electricity generation. As new technologies such as alternating current were developed, the ability to transport electricity over long distances improved significantly, making hydroelectric power a viable and competitive option throughout the country.
In the mid-twentieth century, the construction of large reservoirs, such as the Aldeadávila reservoir on the Duero River or the Alcántara reservoir on the Tagus River, made it possible to supply a large part of the country's electricity demand, becoming key pieces of the energy system both for their generation capacity and for their role in regulating flows.
Recent years have seen a relative decline in hydroelectric production compared to other renewable energies. However, its strategic importance and ability to operate in combination with wind and solar energy keep it at the heart of the energy transition.
Technological development and potential of the hydroelectric sector
The modernization of hydroelectric plants has been a key factor in ensuring that this energy source remains a competitive option in the electricity market. The rehabilitation and improvement of existing facilities have increased their efficiency and reduced operating and maintenance costs.
In recent years, micro-hydro turbines with power outputs below 10 kW have been developed , making it possible to bring electricity to isolated areas without the need for large-scale infrastructure. These micro-turbines harness the kinetic energy of rivers to generate electricity constantly and at low cost.
Small -scale hydropower has also gained ground recently. These types of plants, with a capacity of less than 10 MW, have a reduced environmental impact and can be installed on small rivers without the need for large reservoirs. This has opened the door to new opportunities for energy generation in rural or hard-to-reach areas.
Today, Spain has around 800 hydroelectric plants, many of them small installations spread throughout the country. And although large plants, such as Adeadávila or Alcántara, represent 50% of the country's total hydroelectric capacity, small installations remain a fundamental part of the system for the use of resources on a smaller scale.
The future of the sector lies in continuing to adapt existing infrastructures and maximising the use of hydropower, ensuring sustainability and energy efficiency. With adequate regulation and support at state level, hydropower is expected to continue to be a key part of the Spanish energy mix for decades to come, playing a crucial role in the fight against climate change.
Hydropower is an essential part of Spain's energy tradition. Although its importance has diminished with the growth of other renewable energies, it remains a pillar of the electricity sector, both for its ability to generate clean energy and for its stabilizing role in the national electricity system.