Cómo eliminar la sal del agua salobre y crear energía en ese proceso. Esta es la clave del acuerdo que ha firmado Sacyr Agua con la holandesa Red Stack a través del cual colaborarán en varios procesos deelectrodiálisis. 

El proceso de electrodiálisis reversible (EDR) permite desalar aguas salobres de distinta procedencia, mientras que el proceso inverso, la electrodiálisis reversa (RED), nos permite generar energía a partir del gradiente salino entre una salmuera y una fuente de agua dulce.

En Sacyr contamos con experiencia en EDR, dado que construimos la planta de Abrera, en Barcelona, la más grande del mundo de esta tecnología, con 200.000 m3/día y operamos otras plantas como la de Valle Guerra (San Cristóbal de La Laguna, Tenerife), en la que desalamos aguas residuales previamente tratadas mediante un MBR (Reactor biológico con membranas)  para obtener agua de calidad para el regadío.

Por otro lado  mediante la electrodiálisis reversa (RED), la diferencia de salinidad entre dos corrientes (salmuera y agua dulce) genera energía.  Además, nuestro interés también se centra en utilizar la tecnología de electrodiálisis inversa o reversa en obtener energía de la mezcla de salmuera de plantas desaladoras con efluentes de plantas de tratamiento de aguas residuales municipales.

Uso sostenible para la salmuera

Sacyr y RedStack han demostrado con éxito la tecnología RED a escala piloto en el proyecto LIFE HyReward, financiado con fondos europeos, donde se han conseguido recuperaciones de energía de hasta 0,3 Kw-h/m3. 

En LIFE HyReward hemos explorado la generación de energía eléctrica renovable a partir de la salmuera producida en el proceso de desalación, con el objetivo de mejorar la eficiencia energética del proceso, en un proceso de desalación más sostenible que combine la ósmosis inversa con la electrodiálisis inversa. La integración de este proceso con la tecnología convencional permite mejorar la eficiencia energética, gracias a la recuperación de la energía eléctrica contenida en la salmuera obtenida, previamente a su descarga en el mar, y, por tanto, las emisiones de CO2.

Las partes han acordado establecer una cooperación a largo plazo, en la que Sacyr implementará las pilas REDstack EDR y RED en proyectos de eliminación de sales y producción de energía a partir de salmueras. Además,  se está estudiando en la actualidad la posible ubicación de una planta piloto con la tecnología EDR desarrollada por RedStack, que cuenta con una serie de ventajas (mayor productividad, menor consumo), frente a otros fabricantes.

The terrain that characterizes the surroundings of the Sicilian city of Catania is unique due to the omnipresence of Mount Etna. The eruptions over time have shaped a capricious and highly variable subsoil. 

In this environment, we will develop a major railway project: the Metropolitana di Catania expansion, with a budget of nearly 800 million euros. The extension covers almost 14 km of line, of which eight and a half are underground sections of various kinds. This expansion will connect several towns in the metropolitan area.

Ferrovia Circumetnea (FCE), an agency under the Italian Ministry of Infrastructure and Transport, awarded SIS—a permanent consortium formed by Finninc (51%) and Sacyr (49%)—a section between the towns of Misterbianco and Paternò in September 2023, and in December 2024, a complementary section between Monte Po (Catania) and Misterbianco, connecting with the currently operational line.

This project will feature the use of a new and uncommon tunnel boring machine known as the Variable Density TBM (VD-TBM). Only about 20 machines of this type have been ever operated worldwide. 

The handover ceremony for the TBM took place on May 27, with representatives from Herrenknecht (the TBM manufacturer), SIS (Finninc and Sacyr), and FCE (Ferrovia Circumetnea) in attendance.
 

It stands out for its adaptability to the area’s changing geological conditions. Additionally, due to the frequent seismic activity generated by the volcano, it is necessary to comply with strict seismic standards for both permanent and temporary works.

“A few years ago, the city already undertook a metro project using a conventional TBM, and it ran into significant difficulties due to the unfavorable geological conditions”, explains Miguel Ángel Montón, tunnel manager for this project.

“The ground is extremely complex due to its heterogeneity; there are fissures, cavities, and frequent alternations between basaltic rock—lava—and softer soils. Our TBM is highly adaptable to current conditions; its operating mode can be changed on the fly using four different excavation modes, allowing us to respond in real time to the terrain. It is more complex to operate, but offers that flexibility”, Montón adds.

This isn’t the first time that Montón faces this kind of challenge, as he had a similar experience on Line 3 of the Guadalajara Metro (Mexico). “It was more complicated than usual, but not as challenging as this project,” he states.
 

The TBM began manufacturing in August 2024  and operational testing started in May this year.  Disassembly and transport to the construction site are scheduled to begin in June, with arrival expected in July.

The heaviest components will be transported across the Alps using special convoys to the port of Ravenna (Italy), from where they will be shipped to Catania. The smaller components will be transported by truck to across the Strait of Messina to reach Sicily. 

On-site assembly of the machine will take around three months, followed by approximately two weeks of commissioning and testing. Excavation is expected to begin by the end of December or early 2026.

“We will excavate around 5 km of tunnel with this TBM. The initial contract was for 3,200 meters, and with the most recent award, an additional 2 km were added,” Montón explains.

In a joint initiative between our Innovation team and Sacyr Water and Energy, we’ve launched a renewable energy project at the Pamasa P3 project in Palma de Mallorca. This initiative will support the asset’s decarbonization and help avoid 20 tonnes of CO₂ emissions annually.

Pamasa operates the 45.2 km highway connecting Palma de Mallorca and Manacor (Balearic Islands), a key transport corridor that plays a vital role in regional connectivity.

The new 32 kWp solar installation at Pamasa includes a 41 kWh battery storage system and two EV charging points. A total of 55 photovoltaic modules will generate approximately 47,021 kWh of renewable electricity each year.

Miguel Bauzá, Operations Director at Sacyr Concesiones, said:"This project reinforces our commitment to renewable energy and sustainable mobility".

Once operational, 42% of Pamasa’s electricity needs will be covered by solar panels, rising to nearly 70% with the addition of battery storage.

Of the total energy generated:

• 42% (19,749 kWh) will be used for direct self-consumption
• 27% (12,696 kWh) will be stored for use at night
• The remaining 31% will be fed into the grid

The project will also save an estimated 2,000 liters of fuel each year thanks to the new EV charging stations.
 

Driving decarbonization 

This is one of nearly 100 initiatives in our Decarbonization Plan, which spans Sacyr’s various business units.

These efforts are coordinated through specialized working groups that promote our climate strategy by tracking both emissions reductions and economic savings across each project.
 

Other solar installations

At the Turia Highway Control Center in Valencia, we’ve built a 120 kWp solar array using 570 Wp modules and a 100 kW inverter. This setup produces around 170,000 kWh annually — enough to meet 34% of the center’s energy needs.

In Cádiz, at the Aguas del Valle del Guadiaro facility, we installed a 250 kWp solar system with four 50 kW inverters, producing around 390,000 kWh per year and supplying 20% of the site’s energy consumption.
 

In Santa Cruz de Tenerife, at the Emmasa desalination plant and various water tanks, we’ve deployed multiple solar installations for both individual and shared self-consumption. Combined, they total 900 kWp using 585 Wp modules and a range of inverter sizes.

On Brazil’s RSC-287 highway, we’ve installed five solar power stations that collectively generate nearly 396,000 kWh annually.
 

Progress from 2020 to 2024

Since our baseline year of 2020, we have:

• Reduced Scope 2 emissions by 28,621 tonnes of CO₂ equivalent
• Generated 4,299 MWh of renewable energy
   

Tenemos nuevo capítulo de Sacyr iPodcast en el que hablamos de innovación con expertos que nos inspiran y nos ayudan a ampliar nuestra visión.

En este nuevo episodio, Marta Gil continúa la conversación sobre industrialización en los procesos constructivos con Ramón Sanchez y Antonio Jiménez-Peña.

Si te perdiste el anterior, puedes verlo aquí

En el capítulo nuevo, analizamos las ventajas de esta técnica constructiva, a través de ejemplos concretos de proyectos industrializados de Sacyr.

Aquí puedes verlo completo:

Gabriel Palacios Hernández
Prevention officer and Head of Drone Operations

Sacyr always strives to undertake our projects with prevention and safety as primary objectives. In pursuit of this improvement, we decided to become drone operators in February 2017, as we believed that the use of Remotely Piloted Aircraft Systems (RPAS) (more commonly known as drones) would yield significant benefits, providing greater agility and safety in fieldwork.

In addition to reducing risks in our sector, they also aid production, becoming smaller, more manageable, resistant to weather conditions, and equipped with features that make their flights more efficient and faster.

Drones have countless applications, with new ones emerging daily, but the challenge lies in discovering these uses because the technology is already here, waiting to be applied.

Infrastructure inspection

In infrastructure inspection, RPAS can perform reviews without requiring a worker to be suspended by a lifeline on a slope or in a basket beneath the deck of a bridge. The risks are substantially lower because the worker is not exposed, and work efficiency is much higher because the task is completed in less time.

The use of RPAS is now widespread in surveying, using photogrammetry to obtain 3D models of terrain and orthophotos, which are high-resolution photographs obtained from the combination of partial photos in which distances, areas, and volumes can be measured with great precision.

Replacing operators with RPAS in confined spaces, inspecting high-voltage towers or wind turbines, and using underwater RPAS for inspecting treatment plants or collectors are tasks already being performed, significantly reducing risks.

It is important to consider that drones have their own usage risks, which, thanks to aviation regulations and their high safety standards, are closely monitored to prevent, primarily, the uncontrolled fall of these devices on people or material goods.

Like any flying device, it is susceptible to ceasing flight in an unplanned manner, becoming a weight that, aided by the speed it acquires in the fall, can be fatal. The smallest professional drones weigh around one kilogram, so we can imagine what they can become in free fall.

Additionally, RPAS are devices with propellers, batteries that could ignite, and are powered by electricity in most cases. All of this can lead to accidents for the people who operate them.

Photogrammetry

In what activities can we use drones within our sector?

- Photogrammetry work for topographic surveying: Photogrammetry has transformed the way surveyors work. Instead of traversing the terrain to be "surveyed," obtaining the different points, now the drone performs that work for them. The arrival of drones with integrated RTK systems has further reduced the need for obtaining control points.
- Building inspection or construction monitoring: The activity of "construction monitoring" through aerial images and videos is increasingly in demand. It is the best viewpoint to see the progress of the work.
- Inspection of structures in civil works: If we use the drone to approach the structure to be inspected, being able to capture images or videos, we avoid placing the worker in those areas and the use of costly auxiliary means.
- High-altitude inspection of high-voltage towers: Traditionally, this activity has been carried out by the worker ascending the tower itself, from an aerial lift, or from a helicopter, which is positioned at the top.  Drones clearly avoid putting the worker at risk of falling from height and at risk of electrocution, among others, incorporating RGB cameras with powerful zooms or with thermographic cameras.
- Confined space inspection: There are already drones of minuscule dimensions that do not suffer damage during their impact in narrow areas, with high-quality television cameras, that can replace operators in these tasks.
 

This is the third chapter of Sacyr iPodcast, a space where we talk about innovation with experts who inspire us and help broaden our perspective.
In this new episode, we delve into the industrialization of construction processes, a key topic in the transformation of the infrastructure sector.

You can watch it here:

In this conversation, Marta Gil, Chief Strategy, Innovation and Sustainability Officer; Ramón Sánchez, Building Engineering Manager at Sacyr Engineering and Infrastructure; and Antonio Jiménez-Peña, Head of the Installations Department at Sacyr Engineering and Infrastructure, explore the main advantages of industrialization in construction.

Industrialized construction involves off-site fabrication of modular components using replicable elements, allowing for faster construction, improved quality, cost reductions, and enhances both sustainability and productivity.

“It’s a different way of doing things. We produce large structural elements with diverse components, transport them to the site, and connect them with others. The key lies in the controlled environment where safe, serial production takes place. At Sacyr, doing things differently—faster and better—is in our DNA,” says Ramón Sánchez.

“Clients are very receptive to the speed potential of industrialized projects. Plus, buildings no longer all look the same —technology enables unique constructions, making them more attractive,” the expert adds.

“We must lead the way in integrating these processes into the workflows of installers who are still using traditional solutions,” says Antonio Jiménez-Peña.

“From an installations standpoint, there’s a wide range of solutions. Right now, we’re seeing significant progress with utility corridors and riser shafts—we’re working on how to integrate them into modular systems,” he notes.

Industrialized projects 

Sacyr’s major projects involving industrialized elements include the Hospital 12 de Octubre in Madrid, the Hospital Sotero del Río in Chile, the Expo 2008 Civic Initiatives Pavilion in Zaragoza, the Hospital Buin-Paine in Chile, the Milan Hospital in Italy, the Velindre Hospital in Wales, the Boadilla Hospital in Madrid, and various residential buildings in Madrid, among others.

ISABEL RUBIO ARROYO | Tungsteno

Almost 100 kilometres off the coast of Baku, in the middle of the Caspian Sea, rises Neft Daşlari, an industrial city built on platforms. Its name, meaning “Oil Rocks,” reflects its function: a vast network of extraction wells and processing plants linked together by kilometres of steel bridges. Accessible only by a lengthy boat ride from the mainland, this enigmatic city floats in the middle of the world's largest enclosed body of water.

A motorway in the middle of the sea

Founded in 1949, Neft Daşlari began with platforms built atop deliberately sunken ships. Over time, it evolved into a vast industrial city, linked by more than 200 kilometres of trestle bridges and supported by nearly 100 kilometres of pipelines transporting oil and gas. At its peak, the city boasted nearly 2,000 oil wells and some 320 production plants.

But Neft Daşlari is about more than industry—it has homes, shops, a theatre, a heliport and even a soccer field. Trees were even planted atop steel structures, and at its height, the city housed over 5,000 inhabitants. In recent decades, however, the population has dwindled and much of the infrastructure has fallen into disrepair, with some parts claimed by the sea.

Oil Rocks has served as the dramatic setting for numerous documentaries and films, including scenes from the 1999 James Bond film The World Is Not Enough. It has also inspired renowned Azerbaijani artists, such as composer Gara Garayev and artist Tahir Salahov. Filmmaker Marc Wolfensberger, who shot the movie Oil Rocks: City Above the Sea, described the site as “beyond anything I had seen before.” As he told CNN, it was like “a motorway in the middle of the sea” that stretched out “like an octopus.”

Trailer for the documentary Oil Rocks: City Above the Sea. Credit: Marc Wolfensberger

"The Island of Seven Ships," a symbol in Azerbaijan

To shield the structure from the wind and waves of the Caspian Sea, seven decommissioned ships were deliberately sunk, their hulls forming an artificial bay around the original island. “Some of those ships are visible on the surface of the water where they were buried,” Mirvari Gahramanli, head of the Oil-Workers Rights Protection Organisation, told CNN. In Azerbaijan some refer to Neft Daşlari as “the island of seven ships” and even “the eighth wonder of the world,” she added.

Today, the oil field remains operational. Over the decades, 1,983 wells have been drilled, with 432 still active. According to SOCAR, Azerbaijan’s state-run oil company and the operator of Neft Daşlari, the field produced an average of 2,865 tons of oil per day as of 1 January 2024. Since production began, the site has yielded a total of 179.8 million tonnes of crude oil and 14.092 billion cubic metres of natural gas. Peak output was reached in 1967, when it produced 7.6 million tonnes of oil—about 4.5% of the total cumulative volume.

The industrial city is still operational with more than 400 active wells. Credit: SOCAR

The uncertain future of the “floating” city

Neft Daşlari’s importance has declined in recent decades, overshadowed by the development of larger fields and fluctuating oil prices. “The production at Neft Daşlari supplies only a minor part of Azerbaijan's oil production,” explains Brenda Shaffer, an energy expert at the U.S. Naval Postgraduate School, who has advised oil and gas companies in the Caspian region. As output has declined, so too has the population, now estimated at around 2,000. Moreover, the floating city has not been without controversy: beyond the danger faced by those living or working there due to extreme weather conditions, Gahramanli has raised concerns about the discharge of raw sewage and reports of oil spills.

The floating city’s production now accounts for only a small share of Azerbaijan’s oil output. Credit: SOCAR

With its reserves gradually running dry, the future of this sprawling offshore settlement remains uncertain. Shaffer suggests it could one day become a tourist attraction. Filmmaker Marc Wolfensberger envisions a different future: “It’s really the cradle of offshore oil exploration,” he said, imagining it repurposed as a museum. As for the risk of it sinking—either due to structural fatigue or the effect of climate change—Mirvari Gahramanli was firm when asked by the BBC: “The island is not about to sink and, at the moment, no such risk is foreseen.”

Tungsten is a journalistic laboratory that explores the essence of innovation.

ISABEL RUBIO ARROYO | Tungsteno

Coastal flooding worldwide surged by almost 50% between 1993 and 2015, according to a study by Nature Communications. And the future looks more alarming: by 2050, coastal areas currently home to 300 million people could face annual inundation. As climate change accelerates, mitigating the impact of flooding is crucial for our survival. Here’s how architects and designers are building resilience into structures—one innovative solution at a time.

Architectural innovation against flooding

"While many buildings are decades old, new innovations in architecture and construction practices are showing how buildings can survive major flooding events without leading to a total loss of property," says TrapBag, a company that designs flood control systems. The company sees a need for more flood-proof housing: "Even if a new building is not currently in a flood zone, that may change in 20 or 30 years."

One example of a building designed with flooding in mind is the Spaulding Rehabilitation Hospital on the Boston waterfront. It was designed to be elevated above the projected flood level for rare events that are expected to occur once every 500 years. Additional protective measures include berms as barriers and a perimeter drainage system. These features help to reduce the risk of flooding while supporting the hospital’s ability to remain operational—should water reach the ground floor, equipment and workstations can be quickly relocated to higher levels.

Other notable examples include the Bundanon Art Museum in Australia, which features an underground structure and an elevated bridge that allows water to flow underneath; the St Petersburg Pier in Florida, designed to withstand extreme storms thanks to its elevated infrastructure and efficient drainage systems; and the Merrion Cricket Club in Dublin, which uses waterproof concrete and movable barriers for protection. In the UK, the Michael Baker Shed is raised on a sturdy base to keep key areas above flood levels. Meanwhile, DC Water's headquarters in Washington, D.C., was built above the floodplain, while the Pérez Art Museum Miami uses porous soils, rain gardens and native vegetation to defend against rising waters.

Over millennia, fire and floods have sculpted the landscape surrounding the Bundanon Art Museum. Credit: Architizer

How to flood-proof buildings

Very few buildings are completely flood resistant, but their resilience varies according to location. "A home is typically considered flood-resistant if it can experience at least three days of floodwaters without sustaining significant or non-cosmetic damage," says Trapbag. In flood-prone areas, experts recommend building the house on higher ground and opting for raised foundations—between 60 and 90 centimetres high—to keep the structure above the water level.

To reduce the risk of flooding, it is also important that the land around the house is designed to drain water efficiently. The American Society of Landscape Architects suggests preserving natural ecosystems such as waterways, creating parks that manage water, and using green infrastructure such as transportation networks that cleanse and absorb flood water.

The St. Petersburg Pier in Florida has an elevated infrastructure. Credit: St Petersburg Pier

In particularly vulnerable areas, houses are built on stilts or floating platforms to keep them above water. Some houses in Thailand, for example, use steel pontoon platforms. It is also important that they have wind-resistant features, such as reinforced windows, to prevent damage from high winds.

The Tsunami House or how to protect your home from flooding

Even water-resistant houses are designed with the expectation that they might flood. To prepare for this, floors and walls are coated with special sealants, and critical components such as electrical installations, appliances and heating/cooling systems are elevated. One notable example is the curious "Tsunami House" located in Washington State. The ground floor windows are designed to break in the event of flooding, relieving pressure on the walls. The entire ground floor, including the furniture, is made of waterproof materials.

Flood-resistant materials include concrete, glazed brick, foam insulation, steel, treated wood, ceramic tile, waterproof adhesives and epoxy paint. One way to protect buildings against floods is to surround them with concrete walls or flood levees. Some companies offer flexible solutions, such as stackable structures filled with sand or gravel that can be quickly erected as a defence against water.

The Pérez Art Museum Miami uses porous soils, rain gardens and local vegetation to protect itself from water. Credit: ArquitectonicaGEO

The resilience of buildings is also critical because of the health impacts of flooding. Floods can cause injuries, drowning and exposure to contaminated water, increasing the risk of diseases such as diarrhoea, cholera and malaria. In the long term, floods can aggravate existing health conditions and have significant psychological effects. It is therefore essential to have infrastructure that can withstand such disasters.

Tungsten is a journalistic laboratory that explores the essence of innovation.

The implementation of infrastructure and services in developing countries is often not particularly easy for companies or institutions from outside the country. And maintaining them isn’t easy either.

There are several important factors to consider when working toward economic, social, and health development in each region.
The first is the existence of a social cohesion structure. “There must be at least a basic social and political structure with a hierarchy and codes of conduct. The political structure must organize resources, distribute them, and promote a development strategy, stability, and future vision,” explains Ignacio Calatayud, president of HumanCoop, an NGO that works in development cooperation in Africa. Their working philosophy approaches community health through a One Health strategy, which aims to sustainably balance and optimize the health of people, animals, and ecosystems through training local personnel and building infrastructure.

“Political instability, corruption, and insecurity create obstacles that make it difficult to operate in a country,” says Calatayud.

Secondly, there must be a communication and energy infrastructure network around areas with water reserves and certain easily exploitable resources. “Cooperation between states to foster development in this area is important. Collaboration between different institutions—from the smallest local governments to the World Bank—is also key to supporting the maintenance of these structures, which attract investment to their countries,” affirms the president of HumanCoop.

 

The third important factor is adaptation to the local culture. NGOs like UPlanet serve as a bridge between technical knowledge—engineering, in this case—and local authorities and funding entities. “We must adapt our knowledge to the local culture. When a Western structure is introduced, there has to be someone with local knowledge to determine whether that technology can be implemented,” explains José Matías Fernández, president of UPlanet.

Volunteers who support organizations like HumanCoop or UPlanet are essential in maintaining water purification plants, self-sustaining agricultural systems, health centers, schools, and more. But without qualified local human capital, those infrastructures or services will fall into decline.
Recently, volunteers from the Sacyr Foundation—mainly engineers—participated in a cooperation project in Bir Mogrein (Mauritania, Africa).

Their goal was to help repair the town’s desalination plant, which is the community’s source of drinking water, improve the electrical installations of health and water infrastructure, develop a sanitation project at one of the schools, and launch a pilot project for drip irrigation using desalinated water—laying the groundwork for the region’s future agricultural project.

Ithar Association's cancer facility under development in Nouackchott, Mauritania

In this regard, a significant obstacle to working toward prosperous infrastructure in developing countries is the lack of human resources capable of managing the technologies, materials, or construction and maintenance techniques. That’s why continuous local human capital training is so important—and why conditions must be created to prevent brain drain.

The lack of cohesion among Western governments often hampers development cooperation in essential areas such as health, food, or industry in underdeveloped countries. “The globalization of Western ideas is declining. Governments are increasingly reluctant to collaborate. Development cooperation and humanitarian aid are two sides of the same coin, but they are not the same,” explains the president of HumanCoop. “We must help these countries, but at the same time, we must sow seeds for future progress. Otherwise, the work you’ve done today won’t be useful for the future, it’ll be just a short-term fix” Calatayud concludes.

Esta iniciativa nace con el objetivo de inspirar, compartir y sensibilizar sobre la innovación en todas sus formas. En cada episodio, abordaremos temas clave en el ámbito de nuestras áreas de negocio, con un enfoque divulgativo, riguroso y dinámico. 

En los dos primeros episodios, Marta Gil, Directora General de Estrategia, Innovación y Sostenibilidad de Sacyr charla con Ignacio Hernández, Director del Área de Instalaciones de la Dirección Técnica de Sacyr Concesiones. Juntos analizan como la innovación puede transformar las infraestructuras hospitalarias.

“Todo lo que es infraestructura sanitaria es un gran activo para la sociedad, pero consume muchos recursos. Por eso hay que hacerla más eficiente, algo que podemos lograr gracias a la innovación” explica Ignacio.

En esta charla, Ignacio explica la complejidad de los hospitales, unas infraestructuras muy diversas, en las que la interconexión de los diferentes sistemas puede mejorar su rendimiento global. 

Uno de los grandes protagonistas de estos episodios es el Hospital Cognitivo, un innovador proyecto impulsado por un consorcio liderado por Sacyr y aprobado por la Comunidad de Madrid. Este apasionante proyecto, en el que llevamos trabajando desde hace un año, tiene como objetivo desarrollar una plataforma de gestión integral de infraestructuras hospitalarias.

Entre los hitos más importantes alcanzados hasta ahora, destaca la creación del gemelo digital del Hospital del Henares (Madrid), donde se implantarán los avances conseguidos en este proyecto. “Gracias al gemelo digital, tendremos el edificio modelizado, de forma que podemos hacer actuaciones en un entorno virtual, evitando interrupciones en el funcionamiento del hospital. Podemos anticipar acciones, optimizar recursos y tomar decisiones basadas en datos, sin afectar la operatividad del hospital”, subraya Ignacio.

The extension of the L8 is already underway. This project will deliver three new stations—Gràcia, Clínic, and Francesc Macià—and will upgrade the existing Espanya station to accommodate the new alignment and increased passenger flow.

Toni Julià Ventura, Project Manager for the joint venture—comprising Sacyr (27.5%), Ferrovial (27.5%), Copcisa (22.5%), and Copisa (22.5%)—describes the initiative, promoted by the Generalitat de Catalunya, as a key milestone for sustainable mobility in Barcelona.
“With 19 million annual users, it is one of the most socially and economically impactful projects included in the Generalitat’s Infrastructure Master Plan,” explains Julià.

 

The works are divided into two main lots: Lot 1 involves conventional excavation techniques, due to the complex web of existing infrastructure in the area—such as Metro Lines 1 and 3—which makes the use of a tunnel boring machine (TBM) unfeasible. The extension will run from the current terminus, beneath Plaça Espanya and its central fountain, through a sequence of shafts and mined galleries.

Lot 2 begins in the logistics zone of Gran Vía, which hosts the TBM launch shaft. From this point, a 3.7-kilometer tunnel will be driven to connect the new stations at Hospital Clínic, Francesc Macià, and Gràcia. Emergency exits will be constructed at Consell de Cent and Muntaner.

The project is currently in its early stages, with approximately 10% overall progress. To date, most of the utility diversions have been completed, and hydromill (hydrofresa) retaining walls for the Consell de Cent emergency exit have been executed. Construction of the TBM launch shaft walls is ongoing.

In the coming weeks, excavation of the deep retaining walls at Hospital Clínic and Francesc Macià stations—each exceeding 80 meters in depth—will begin. Meanwhile, the TBM components are undergoing detailed inspection before assembly within the shaft. An acoustic enclosure will be installed over the shaft to mitigate noise and environmental impact during tunneling.

Once the main tunnel is completed, cavern excavation will commence. As the TBM bore accommodates only the twin tracks, the cross-section will be expanded through sequential mined phases to form the platform waiting areas and emergency access routes.

Key Figures

•    CO₂ Emissions Reduction: The extension between Plaça Espanya and Gràcia is expected to significantly reduce private vehicle use, saving CO₂ annually.
•    Tunneling Scope: Includes 3,728 meters of TBM-driven tunnel, 378 meters of cavern excavation, and 260 meters of mined tunnel.
•    Minimized Environmental Impact: The originally planned site footprint in Joan Miró Park has been reduced by 40%.
•    Stations and Infrastructure: The project comprises three new stations (Gràcia, Clínic, Francesc Macià), the adaptation of Espanya station, modified interconnection corridors, and two emergency shafts.
•    Contract Duration: The overall contract spans 58 months, divided into two main construction lots.

ISABEL RUBIO ARROYO | Tungsteno

Nearly two-thirds of the world's population experiences severe water shortages for at least one month each year. UNICEF estimates that half of humanity will be living in regions affected by this crisis in 2025. In recognition of World Water Day (22 March 2025), we explore cutting-edge technologies that are revolutionising water management and quality, offering vital solutions to this global challenge.

A crucial filter for hurricanes and floods

The LifeStraw Max is a powerful water filtration device that purifies contaminated water in seconds. According to its creators, it removes nearly all viruses, bacteria and other pathogens, while also reducing sediment, industrial chemicals, and dissolved metals. This filter is crucial for areas lacking access to safe drinking water, or during emergencies like hurricanes and floods, when water supplies may become unsafe. It was even tested in 2022 during the Jackson, Mississippi water crisis, where over 150,000 people had to boil their water after the municipal system failed.

A device that pulls water from the air

"By next year, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world's population could be living under water stressed conditions," warns Genesis Systems. To help address this crisis, the company has developed devices that extract fresh water directly from the air using renewable energy like solar power or conventional electricity.

"It tasted better than the water from my hotel room tap," said a CNET journalist who sampled the water produced by one of these devices. Systems that capture water from atmospheric moisture could become a vital source of supply in the aftermath of natural disasters. In fact, they have already been deployed at a Florida children's hospital impacted by Hurricane Milton.

Genesis Systems device for extracting drinking water from the air. Credit: Genesis Systems

The sensor that monitors your water usage in real time

Droplet is an innovative ultrasonic sensor installed in household pipes to track water consumption in real time. It detects leaks, analyses usage patterns, and helps optimise water efficiency. Through a mobile app, Droplet provides detailed reports of daily, weekly, and monthly consumption, and also sends alerts for leaks or excessive use. One of its standout features is its ability to identify inefficiencies in household water use—for example, detecting if an old toilet is using more water than necessary. This information could help reduce water consumption and save money.

The technology that turns seawater into drinking water

According to the National Oceanic and Atmospheric Administration, 97% of the world's water is found in the oceans and seas. That is why desalination plants have become a key technological solution to combat water scarcity. These facilities use reverse osmosis to remove salt from seawater, transforming it into high-quality drinking water. "Desalinated water has extraordinary quality and purity, as the membranes prevent any type of contaminant from entering it," explains Domingo Zarzo Martínez, president of the Spanish Association of Desalination and Reuse (AEDyR) and director of innovation and strategic projects at Sacyr Agua.

Desalination plants use a process to remove salt from seawater. Credit: Sacyr Concessions

The software that optimises water use for businesses

Waterplan is a software platform that helps companies manage water use more efficiently and sustainably. It combines public data on water sources—such as rivers and aquifers—with internal company consumption data to assess risks like droughts and water shortages in the regions where they operate. This allows businesses to understand how these challenges could impact their production.

Waterplan currently works with more than 30 clients, including Coca-Cola, Amazon, and Anheuser-Busch InBev, helping them visualise the effects of drought and overexploitation on their production. As co-founder José Galindo explains, "water is cheap and plentiful today, but it won't always be; there’s going to be a 30% gap in 2030 between supply and demand. We think that pressure will appear over the next 10 years."

Tungsten is a journalistic laboratory that explores the essence of innovation.

In the latest installment of the “Circular Transformation” series, we meet Francisco Navarro, David del Río, and Marta Pereira from the Quality and Environment team. They share some of the practices being implemented on construction sites in Madrid to improve circularity, optimize resource use, and prevent waste generation.

1. Sack Management: We separate clean used sacks (e.g., for cement, plaster, etc.) directly on-site so they can be 100% recovered as raw material for new sacks, thus avoiding their classification as hazardous waste.
2. Plasterboard Recycling: We return leftover plasterboard to Placo Saint-Gobain for recycling and reuse in the manufacturing of new boards, ensuring 100% material recovery.
3. Wood Pallet Return: We reuse pallets for transporting materials, reducing the need to manufacture new ones and minimizing wood waste generation.

Discover more circular initiatives:

We built a brine collector that extends the lifespan of materials

We wrap up the water cycle in Langosteira

We are headed towards Zero Waste by reusing materials in La Llagosta

The construction and maintenance of dams require on-site work, which entails additional time and costs. For this reason, Sacyr Maintenance, in collaboration with Sacyr Holding, is working on 3D dam modeling using Pix4D software, which generates digital twins from drone imagery.

"We designate the area for the drone to fly over, and it captures overhead images along the entire path, scanning the dam's entire surface. This enables the creation of digital models with precise distance measurements," explains Gabriel Palacios, Prevention officer and Director of Drone Operations at Sacyr.

"For example, deteriorated walls with cracks can be dangerous to inspect up close. The drone follows the wall and captures a composite photograph, similar to an orthophoto but aligned with the wall, providing high-definition imagery to identify structural deficiencies. The drone can fly very close to the dam, and the closer it gets, the more detail it captures," Gabriel adds.

The digital model allows for the mapping of terrain topography and structural features, volume calculations, measurements of all visible elements, and comparative studies of different digital models taken at various times.

"Having a digital model provides a 3D-scale representation of the dam, similar to a physical model, where we can visualize, measure, and plan necessary work. This approach offers a wide range of possibilities while reducing time and costs compared to traditional methods," explain José Luis Barragán and Sergio Maestre, Head of dams O&M at Sacyr Maintenance.

Multiple Advantages

The key benefits include time savings, cost reduction, and improved safety. Often, small measurements are needed to determine an element's dimensions. Without an accurate digital model, this would require an on-site visit to the dam, which is often located in remote or difficult-to-access areas.

This technique is currently being used for dam modeling, although similar methods have long been employed in topography for land measurement and stockpile assessment.

3D modeling has already been implemented at the Linares del Arroyo (Segovia), Cazalegas (Toledo), and Estremera (Community of Madrid) dams. The goal is to extend this initiative to all dams under our maintenance program.

With Sacyrian accent

Lucía Cecilia Mercado

When you tell people that you’re going to Mauritania—“Where is that?”—to volunteer in a cooperation project, you get all kinds of reactions: disbelief, admiration, confusion. You take all these reactions, mix them with your own feelings, and create your own cocktail of emotions.

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And so, I find myself wondering: What drove me to take part in this project that made the collaboration between the Sacyr Foundation, HumanCoop, and UPlanet in Mauritania possible?

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In the photo, from left to right: Lucía, Matías, Natalia, Rodrigo and Iván. 

It’s a mix of many things, and here, I’ll try to explain the most important ones for me.

Curiosity. Everything I do in my daily life is guided by a desire to discover what lies beyond my own experiences, knowledge, and immediate surroundings. Exploring different ways of life, other countries, and new cultures has always motivated me to step outside my comfort zone, study philosophies far from the Western perspective, and try to understand other approaches to life.

Empathy for those in need. I try to put myself in the shoes of people who lack the things we take for granted—running water at home, hot water from the tap, a variety of food, a mobile connection, a bed to sleep in. So many things—never mind going to the movies, having a beer, or dining out—that we take for granted about until we travel to places where they are not guaranteed.

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A desire to help create a better world. Life feels empty if we don’t contribute, even in small ways, to improving the lives of others. Taking part in projects like this by HumanCoop and UPlanet gives me purpose, fulfillment, and the chance to become a better person.

Love. Love for others, love for myself by honoring the values that drive my actions, love for different cultures, love for other landscapes like the desert that captivate me.

Admiration.

For people who make projects like HumanCoop a reality. From the first moment I heard Ignacio speak, I admired him. We have so much to learn from people like him, who dedicate their time to helping others—it would take a lifetime to put their lessons into practice. Ignacio’s commitment to the Sahrawi people is contagious to everyone around him. The same goes for his collaborators: Gema, Esteban, and Oscar, whom I deeply respect and admire.
 

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The same admiration extends to José Matías, a former Sacyr colleague through whom I first learned about this project and the NGO he founded, UPlanet. His drive, hard work, and determination to support social and humanitarian causes inspire everyone lucky enough to work alongside him.

And admiration for my engineer colleagues who shared this experience with me, as well as for the healthcare workers of the mission. Their dedication, working late into the night until their lanterns could no longer pierce the darkness, was truly inspiring. I deeply respect the healthcare workers who spent long hours performing surgeries and providing medical care, asking for nothing in return but the satisfaction of helping others. Seeing their exhaustion at the end of the day filled me with respect and admiration. Standing beside them, sharing this experience, is what makes you grow as a person.
 

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Experiences like this don’t just inspire—you become hooked. They make you a better person, help you appreciate what you have, and allow you to contribute, even in a small way, to a humanitarian cause.

When I think of Bir Mogrein, the village in northern Mauritania where five Sacyr volunteers (Rodrigo, Matías, Iván, Natalia, and I, along with my dear Eli from UPlanet) , I feel a constant pull to return. Despite the two days it takes to get there, cold-water showers, sleeping on the floor, in the end it's very minor

To keep working with incredible people like Belali, Fátima, Abba, M. Salem, the supervisors of the desalination plant, the community garden, the health center, the cooks, the drivers, the women of the village, the children…

I want to give a special mention to Belali, who paid really close attention to all our needs while we were working, no matter what. Thank you for being so attentive! 

Lardi, Belali, Lucía, Rodrigo, Iván, Matías y Natalia.

I think of them, and my heart fills with admiration, love, and respect.

I want to see them again.

ISABEL RUBIO ARROYO | Tungsteno

What if nature could save us? What if we rethought how we spend money, consume energy or design greener cities? These are some of the questions posed by the American architect and artist Maya Lin in What is Missing?, a project that highlights the extinction of species and the environmental crisis. We explore Lin's work and how her dedication to nature seeks to foster a greener planet and halt the extinction of species.

Lin rose to fame when still a student

Lin studied at Yale and gained national recognition in her final year when her design won the national competition for the Vietnam Veterans Memorial in Washington, DC. Completed in 1982, the memorial consists of two black granite walls engraved with the names of fallen soldiers—a striking and unconventional tribute that initially sparked controversy, with critics calling it a monument to shame and defeat.

Beyond memorials, Lin's art explores the relationship between humans and the landscape, aiming to deepen the awareness of the spaces we inhabit. "I see myself existing between boundaries, a place where opposites meet; science and art, art and architecture, East and West. My work originates from a simple desire to make people aware of their surroundings," she writes in her book Boundaries.

The Vietnam Veterans Memorial catapulted Lin to fame. Credit: Maya Lin Studio

A slowly dying forest

Her most recent projects include Mapping Our Place in the World... (2023) at Georgetown University; Ghost Forest (2021) in Madison Square Park, New York; and the renovation of Neilson Library (2021) at Smith College, Massachusetts. However, if there is one defining feature of her work, it is her unwavering commitment to sustainability.

A striking example of this is "Ghost Forest", an installation in Manhattan’s Madison Square Park that highlighted the devastating impact of climate change. According to the National Oceanic and Atmospheric Administration (NOAA), a “ghost forest” is a once verdant woodland now ravaged by the effects of sea level rise and saltwater encroachment. Lin's project represents "a majestic forest of cut trees that will slowly turn grayer and more ghostly as the park's grand living trees go through all seasons". After six months of exposure, the 49 Atlantic white cedars were brought down in 2021 and donated to the Bronx-based educational organisation Rocking the Boat, to be used by students to build boats.

The work Ghost Forest consisted of 49 Atlantic white cedars. Credit: Maya Lin Studio

What if the solution lies in nature?

Ghost Forest is part of What is Missing?, a project driven by experts in art, science, conservation, and communication that aims to raise awareness of biodiversity loss and the impact of climate change on ecosystems. "Nature-based solutions can reduce emissions by 45-90%, feed two billion more people, and protect and restore species throughout the world," says Lin, who leads the project.

The experts behind the project say that reforming agriculture and livestock farming could reduce annual greenhouse gas emissions by 20-40%, while protecting and restoring forests could cut emissions by 15-30%. Sustainable fisheries and aquaculture would contribute a reduction of 5-15%, and protecting resilient coastlines and wetlands would reduce emissions by 2-5%.

Maya Lin explains her relationship with the natural world. Credit: WSJ Style

For Lin and the other key figures involved in the project, transitioning to renewable energy like solar and wind power, fostering more sustainable cities and industries, and expanding protected land and marine areas are essential. As 19 authors stated in a 2019 article in Science Advances: "Complex life has existed on Earth for about 550 million years, and it is now threatened with the sixth mass extinction. If we fail to change course, it will take millions of years for the Earth to recover an equivalent spectrum of biodiversity. Future generations of people will live in a biologically impoverished world."

Tungsten is a journalistic laboratory that explores the essence of innovation.

Sacyr has extensive experience in port and harbor construction that has now been transferred to the second phase of the Central Breakwater in the Expansion of the Port of Bilbao. With this project, Sacyr provides agile and sustainable construction solutions to culminate three decades of works in Bilbao's port area. 

Miguel Tejeda, Project manager, explains that the initiative stems from the growing demand for freight traffic at the port and the need to expand port facilities in the Pass due to the rezoning of port areas located upstream of the estuary for urban development purposes.

The Central Breakwater represents the final stage in the Expansion of the Port of Bilbao in the Outer Pass.

In the Summer of 2024, the Bilbao Port Authority awarded a joint venture, led by Sacyr Engineering and Infrastructure, the contract for this second phase. This phase encompasses a 310,000 sqm area and is scheduled to be completed within two years.

The project applies construction methods such as the use of reinforced concrete caissons and the development of a mass concrete superstructure, with an optimized design aimed at minimizing disruptions to existing port operations and maximizing the efficiency of the new quay. 
 

The floating dock is made of four towers that have been brought by ship from Lisbon.

Additionally, the project includes the construction of 1,011 as an meters of new berthing docks: 664 meters for the new A3 Quay and 347 meters for the existing A4 Quay.

The caissons will be manufactured on-site using the Sacyr Uno floating dock.

The dock measures 56 meters in length, 36 meters in beam, and 15.9 meters in depth. During the process, the designed prop will be adjusted afloat, utilizing the naval stability of the caisson to optimize the slab construction for the subsequent caisson. 

The floating dock comprises four towers and 16 ballast tanks, enabling the platform to be submerged to the desired depth. This allows for smooth formwork sliding and ensures the stability of the entire assembly.

The main construction works include the fabrication of new concrete caissons and their subsequent filling with sand dredged from maritime deposits. Additional activities include constructing the breakwater, creating pier backs with land-based placement of riprap, executing the seaside and landside superstructures, extending the rainwater drainage network and installing port equipment.

The second phase will focus exclusively on building the vertical quay using reinforced concrete caissons topped with a mass concrete superstructure. 18 concrete caissons in total will be constructed using a floating platform or caisson-builder that facilitates continuous production.

Once completed, the caissons will be floated to their designated positions at the quay. They will be anchored by filling their cells with water until they sink to rest on the prepared foundation. Afterward, the cells will be filled with material, the joints will be sealed using concrete piping, and the gaps between the caissons will be filled with gravel.

Environmentally Friendly Construction

The project has undergone an Environmental Impact Assessment and has received the corresponding Environmental Impact Statement (EIS). It incorporates measures to mitigate turbidity during construction, such as the use of containment barriers and anti-turbidity curtains. Air quality and noise levels will also be closely monitored.

Furthermore, the filling material for the esplanade will be sourced from excavation surpluses from nearby projects.

The materials to fill the caissons will be extracted from a marine area parallel to the Petronor dike, located two miles off the coast to the north, spanning approximately 7.9 square kilometers.

Extensive Port Construction Experience

Sacyr has considerable expertise in port infrastructure projects, such as the extension of the Punta Sollana dock in the Port of Bilbao, the jetty at the Port of Langosteira in A Coruña, the protective works and Cruise Ship Dock at the North Extension of the Port of Valencia, the expansion of the Port of Garrucha (Almería), the fishing port of Blanes (Girona), and the Port of Marín.

Sacyr's maritime bases have allowed the company to develop many projects in the Azores Islands.

By implementing several initiatives to optimize resource use and minimize environmental impact, this project serves as a prime example of our commitment to circularity.

Walter Díaz, Head of Quality, Environment, and Energy for the project, explains that 2.3 km of polyethylene pipes from the project's bypass system—temporary infrastructure ensuring brine transport during pipe replacement—have been repurposed for recycling. This initiative promotes the circular economy and reduces waste generation.

Reusing Milled Pavement

The milled pavement from the project has also found a second life. The Sallent City Council will reuse 657 m³ of asphalt from Section VII for future works. Meanwhile, the company Deumal will use 70 m³ of asphalt from the Sant Benet road section to produce new bituminous mixtures.

Additionally, 40 certified PEFC wooden units have been acquired for the project, guaranteeing their origin from responsibly managed forests.

Environmental Improvements

This new infrastructure brings significant environmental benefits: it reduces the salinity of the Llobregat and Cardener rivers, replaces an outdated system with a modern, safer, and more efficient one, and promotes the use of reclaimed water in mining operations, freeing up potable water for other purposes.

The Quality, Environment, and Energy Department ensures compliance with the project’s environmental requirements by reporting relevant data and verifying its accuracy. Furthermore, the circular economy measures implemented are closely monitored to share best practices and replicate them in other projects.

Sacyr Circular Transformation

Sacyr Circular Transformation is our monthly series highlighting circular economy initiatives across our global projects, all aligned with our Zero Waste Plan.

Revisit the first edition of this series, where we explain how we close the water cycle in Langosteira.

ISABEL RUBIO ARROYO | Tungsteno

The Salt Cathedral is undoubtedly one of the most remarkable places in Colombia. True to its name, it is constructed entirely from salt, but that’s only part of its allure. Situated 180 metres below the surface, it features a labyrinth of tunnels and massive salt-carved crosses.

In this piece, we explore the process behind its construction and uncover the secrets hidden within one of Colombia's greatest works of engineering, celebrated as the country's first wonder.

The spiritual refuge of miners

The Salt Cathedral is located in Zipaquirá, a picturesque mining town near the capital, Bogotá. To access the site, visitors pass through a long tunnel lined with eucalyptus logs and illuminated by green lights, adding to the mysterious atmosphere of the place. As you proceed, you enter a series of caverns and chambers adorned with majestic crosses carved in salt and illuminated by coloured lights that lend the space a mystical touch. The cathedral features three central naves symbolising the birth, life, and death and resurrection of Christ, along with an enormous basilica dome.

The indigenous Muisca people were the first to discover these salt deposits more than six centuries ago. Later, Spanish conquistadors arrived in search of El Dorado. "Instead of a city of gold, they discovered a city of salt," Luis Alfonso Rodríguez Valbuena, former mayor of Zipaquirá, told The Washington Post. In its early days, this cathedral was much more modest. Miners initially prayed in a small sanctuary built in the 1930s.

In this humble sanctuary, they prayed to the Virgin of the Rosary of Guasá, the patron saint of miners, seeking protection from toxic fumes, explosions, and the many dangers they faced daily while extracting tonnes of salt. “The work was very dangerous,” Juan Pablo García, the cathedral's administrator, told US broadcaster NPR, referring to the hazardous conditions in Zipaquirá’s salt mines, where commercial mining began in 1815. “Every day that they came out of the mine alive was a reason for giving thanks,” he added.

Access to the Zipaquirá Salt Cathedral is through a long tunnel lined with eucalyptus logs. Credit: Zipaquirá Salt Park

The underground reconstruction of a Colombian symbol

The first sanctuary was eventually closed due to instability, and the cathedral itself was shut down in 1992 after years of blasting, hammering and drilling caused structural problems. A public competition was held to replace it, and several proposals were received. The winning design came from Colombian architect Roswell Garabito Pearl, who designed a new church.

A team of more than 100 miners and sculptors was assembled to construct the new cathedral, which is located 200 feet (about 60 metres) below the original. One of the greatest challenges was moving the imposing rock salt altar from the old sanctuary to the new site, according to retired mining engineer Jorge Castelblanco, who was involved in the reconstruction. The altar weighed 16 tonnes and workers had to cut it into three pieces to transport it.

The Salt Cathedral is one of Colombia's most popular tourist destinations. Credit: Travel Life Experiences

Zipaquirá's underground jewel

The Salt Cathedral opened its doors in 1995. Guides often emphasise that everything inside is hand-carved, making it a true masterpiece of engineering and craftsmanship. Since 2024, it has also housed the Monumental Underground Museum 180. Nestled in the depths of this Colombian architectural marvel, the museum showcases 22 marble and stone sculptures crafted by national and international artists.

The crosses of the Salt Cathedral are hand-carved. Credit: Zipaquirá Salt Park

Over the years, the Salt Cathedral has become one of Colombia's most popular destinations for tourists and pilgrims alike, drawing more than 600,000 visitors annually. Although it is not part of the Seven Wonders of the World, it earned a place as one of the Seven Wonders of Colombia in 2007, receiving the highest number of votes in a national competition. Furthermore, in 2024, the Andean Parliament recognised it as a landmark of cultural, natural, and historical heritage within the Andean region.

Tungsten is a journalistic laboratory that explores the essence of innovation.