07 JAN 2022

Villarino, a "rejuvenation" at 51

Iberdrola has refurbished, for the first time in its history, two of the three low-pressure valves at the Villarino de los Aires hydroelectric power plant in Salamanca. This is a reversible installation, capable of generating energy by turbining water in one direction and pumping it in the opposite direction depending on the needs of the electricity system. Its dam is built on the bed of the Tormes River, in the municipality of Almendra, while the power station is on the bed of the river Duero, in the town of Villarino de los Aires, in the heart of the Arribes.

Image of Villarino refurbishment

The engineering work, preliminary work and construction of new parts began in 2020 and the dismantling, refurbishment and assembly work was carried out in a tight 18-week programme between March and July 2021, despite the complexity of the work and the health crisis.

The valves, with a diameter of 5 metres and a total weight of 81 tonnes, are located in two caverns 100 metres below the surface.

The refurbishment has included the replacement and improvement of actuating parts, as well as the anti-corrosion treatment of the valves themselves. Some of these parts have been redesigned to improve future work on the valves themselves.

During this work, Iberdrola also inspected the penstocks leading to the power plant's generator sets and applied anti-corrosion treatment to the pipes where the valves are housed. In addition, Iberdrola also took the opportunity to carry out work such as the replacement of the plant's cooling motor control centre.

These works have had an important local component, both in terms of industrial suppliers and the involvement of up to 350 workers*.

Villarino has six reversible sets with a total of 810 MW of power; four of them were commissioned in 1970 and the remaining two in 1975, registering an average annual production of close to 1.200 GWh. The six turbines of this hydroelectric power station can move up to two hundred and thirty-two thousand litres every second.

Its arch dam, the highest in Spain, has a height of 202 metres and its reservoir has a capacity of more than2500 hm3. Its construction almost half a century ago was a milestone in civil engineering at the time and remains so today.

The engineering design of the power plant was developed in an unprecedentedly complex underground work. The water from the Almendra reservoir travels to the power plant through a 15-kilometre-long, 7.5-metre-diameter, 100-metre-deep gallery excavated in the rock. At the end of its journey, the gallery splits into three five-metre-diameter galleries, each of which in turn splits into two two-metre-diameter galleries. Each of them feeds one of the six turbine-alternator sets installed in the power station. The network of pipes ends up draining into the Aldeadávila reservoir.

Together with the other two plants in Salamanca, Saucelle and Aldeadávila, they have an average annual production of around 5,000 GWh, which represents more than 40% of the hydroelectric energy production of Castile and León, and more than 15% of the national production.

From the Duero Waterfalls to global energy leadership

Iberdrola's commitment to Castile and León is part of the company's deep ties with this region, where it was founded more than 115 years ago and from where it has been promoting the energy transition towards renewable, clean and competitive energies that promote the development of a sustainable and environmentally and socio-economically responsible society.

Iberdrola's commitment to clean energies began precisely with the promotion of the Saltos del Duero and this commitment, more than a century later, has materialised by becoming a global energy leader, the leading wind power producer and one of the largest electricity companies in the world in terms of stock market capitalisation.

In Castile and León, Iberdrola is a leader in the development of these energies, with the management of more than 5,2000 MW of renewable energy - 3,500 MW of hydroelectric - which consolidates the region as the autonomous community with the most "green" megawatts installed by the company in Spain.

One of the most important milestones in Iberdrola's history

The construction of the Duero Waterfalls began practically at the dawn of the 20th century, in the wake of the euphoria awakened by the technical discoveries in the transport of electricity. It was then that many Spanish industrialists, accompanied by the best engineers of the time, set out to explore the Iberian river basins.

These were surprising journeys, as the richest areas for harnessing water for electricity generation were in difficult locations and far away from the towns.

The mighty river Duero, despite being a vehicle of transport for long periods of time, concealed an unimaginable treasure in the form of energy in its lower section. It was the engineer José Orbegozo who, after studying the river and glimpsing the entire canyon, realised the enormous possibilities of the international section and the magnitude of the project, which required a global treatment of the same, in accordance with the importance of the exploitation. With the aim of developing all the concessions under a single management, the Sociedad Hispanoportuguesa de Transportes Eléctricos was created in July 1918, which in 1928 became known as Saltos del Duero (Duero Waterfalls), one of the seed companies of today's Iberdrola.

The project consisted of building powerful waterfalls that would take advantage of the fantastic waterfall and create large reservoirs on the Esla and Tormes rivers. These reservoirs would regulate the flow and guarantee the production of the powerful power stations to be installed downstream, either on the national or international section of the Duero, which, on the border between Spain and Portugal and along its 160-kilometre course, had a gradient of 400 metres.

This approach was completely innovative and also risky, as it created a source of energy in the Esla that was five times the consumption of the whole of Spain and was the regulatory base of a system comprising the Ricobayo, Villalcampo, Castro, Saucelle and Aldeadávila waterfalls, the last two on the international section of the Duero. This ambitious project represented, as a whole, more than 10 billion kilowatt hours (kWh) of annual electricity production.

The Ricobayo plant on the river Esla was commissioned in 1935, followed by Villacampo (1949), Castro (1952), Saucelle (1956) and Aldeadávila (1962), all on the river Duero, with a total installed capacity of 3,560 megawatts (MW).

With the use of the Duero waterfalls, the construction of large regulating reservoirs began, with power stations at the foot of the dams, which until then had not been built either in Spain or in Europe.

This project represents one of the most important milestones in Iberdrola's more than century-long history, a history that is the sum of the efforts of several generations who have known how to take advantage, at all times, of the opportunities of the electricity market, with the ultimate aim of responding to the demands of industrial development and the well-being of Spanish society.

* Works at headquarters: TAMOIN (Basque country), SISTEMAS ESPECIALES DE METALIZACIÓN - SEM (Asturias), GARCÍA INDUSTRIAS, OBRAS Y MANTENIMIENTOS - GIMMOS (Andalusia), NERVIÓN INDUSTRIES, ENGINEERING (Basque country), CONTRATAS Y OBRAS SAN GREGORIO, S.A. (Castile and León), ISIDRO BENADE (Galicia), SUMERGIA (Madrid), ZEUKO, S.A. (Basque country), TECINSA (Castile and León), SGS TECNOS, S.A. (Madrid), ZANTZA SEGURIDAD, S.L. (Basque country), GESDIM (Galicia), FLYVIEWS (Madrid), GALACUATIC (Galicia), MECANIZADOS ACEBRON, S.L. (Galicia), AIMEN, (Galicia), GRÚAS PÉREZ COCO (Castile and León), GRUINMOBIL, S.L. (Castile and León), TERMISER SERVICIOS INTEGRALES, S.L. (Castile and León), ELECTROMECANICA JOSMAR (Castile and León), EUROCONTROL (Castile and León), APPLUS (Castile and León), TAGYDAO, S.L. (Madrid), LASERLAN SERVICES (Basque country), GRÚAS DUERO, S.L. (Castile and Leon), ARBEGUI, S.A. (Bizkaia), GRIÑÓN SERVICIOS INDUCCIÓN TÉRMICA, S.L. (Madrid), OCA INSPECTOR, S.A. (Madrid). (Madrid), OCA INSPECCIÓN CONTROL Y PREVENCIÓN, S.A. (Castile and León), Supplies and external services: METALURGICA GALLEGA (Galicia), TALLERES ARATZ S.A. (Basque country), CT INGENIEROS (Madrid), FERMAK 2000, S.L. (Castile and León), TALLERES ÓÑIGA (Castile and León), TALLERES ASTORGA, S.A. (Castile and León), MECANIZADOS ACEBRON, S.L. (Galicia), DISTRIBUCIONES COMERCIALES YUSTE (Castile and León), ELEKTRA, S.A. (Castile and Leon), SKF ESPAÑOLA, S.A. (Cataluña), SUMINISTROS BEZABALA S.A. (Basque Country), BOMBAS CAPRARI, S.A. (Castile and León), TRELLEBORG SEALING SOLUTIONS (Madrid), TENNECO (Germany), AMARA, S.A.U. (Madrid), POLYLUX, S.L. (Catalonia), AIMEN, (Galicia).

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Video largo: https://wetransfer.com/downloads/7600fde98cdc044d6a1762140c79073b20220103150208/0fc96288703fe2b3d7377abad02246cf20220103150240/f77250