Spain has been developing its hydroelectric potential for more than 100 years, creating a highly efficient hydroelectric generation system. Hydropower remains the most mature renewable technology in the country, especially due to the favorable geography and the presence of numerous dams, which allow for 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.
In Spain, there is a total reservoir capacity of 55.000 hm³, of which approximately 40% is intended for hydroelectric generation, a significant proportion at European and global level. Larger power plants are essential for the country's energy balance, especially to compensate for the intermittency of other renewable sources such as wind and solar.
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%).
Today, Spain has an installed capacity of 17.792 MW in hydroelectric energy, which represents 19,5% of the national total. The autonomous communities with the greatest installed capacity are Catalonia, Galicia and Castile and Leon, thanks to its abundance of 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
Hydroelectric power was the main source of electricity in Spain for much of the 20th century. In the 1940s, more than 100,000 people were using hydroelectric power. 92% of energy of renewable energy produced in the country came from hydroelectric plants. This predominance continued until the introduction of hydrocarbons and nuclear energy.
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 one in Aldeadavila on the Duero River or the Alcántara reservoir on the Tagus, 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 maintaining this energy as a competitive option within the electricity market. rehabilitation and improvement of existing facilities has allowed them to increase their efficiency, as well as reduce operating and maintenance costs.
In recent years, micro hydraulic turbines with powers lower than those of 10 kW, which has made it possible to bring electricity to isolated areas without the need for large infrastructures. These microturbines harness the kinetic energy of rivers to generate electricity constantly and at low cost.
La mini hydraulics has also gained ground in recent times. These types of plants, with a power of less than 10 MW, have a reduced environmental impact and can be installed in small rivers without the need for large reservoirs. This has opened the door to new opportunities for generating energy 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.