By Fernando Pessanha & Gilles Mirol, Hydnum Steel
At Hydnum Steel, we are not merely constructing a steelworks; we are laying the groundwork for a cleaner, more resilient, and more competitive future for Europe’s industry. As producers of clean flat steel in Spain, we have embraced a sustainability approach that goes beyond emissions elimination; it means rethinking the entire value chain, from energy and raw materials to waste, water, digitalization, and logistics. From the initial design phase through everyday operations, every decision has been made with a long-term sustainability mindset.
A new benchmark for flat steel in Europe
Our greenfield plant project is located in Puertollano, Spain, and is designed to produce up to 2.7 million tonnes of flat steel per year with cutting-edge technological solutions for zero-emission production. This output represents a strategic contribution to both the national and European steel industries, with direct impact on key sectors such as automotive, construction, renewable energy, and household appliances.
Hydnum Steel is fully aligned with the vision of a re-industrialized, resilient, and climate-neutral Europe, in line with EU initiatives like the Clean Industrial Deal and the push for a dedicated Steel Action Plan for the sector. We are committed to sustainable, digitalized, and competitive processes, supported by access to renewable energy, green financing and policy tools such as the Carbon Border Adjustment Mechanism. These measures are essential to driving industrialization and ensure that Europe can lead the transition to low-carbon steel without sacrificing competitiveness.
With an initial investment of €1.65 billion and more than 1,100 direct jobs projected at full operational capacity, Hydnum Steel is more than just a steel plant: it is part of a broader industrial, economic, and social transformation for the province of Castilla-La Mancha and for Spain as a whole.
Responding to a strategic need
Today, the Iberian Peninsula imports between 5 and 6 million tonnes of flat steel per year, while the EU carries a deficit of over 11 million tonnes. This not only poses a risk to the trade balance and industrial employment but also creates dependence on external markets with lower environmental traceability.
As demand for clean steel grows, especially in sectors governed by stringent climate policies such as automotive and construction, Europe must strengthen its internal capacity to produce low-carbon steel competitively. Hydnum Steel arrives at precisely the right moment to fill this gap, leveraging cutting-edge technology, abundant clean energy, and a long-term vision focused on sustainability and strategic self-sufficiency.
Zero emissions as an operational standard
Hydnum Steel integrates a suite of innovative technologies that enable the elimination of emissions in its production process. Our model is based on an electric arc furnace (EAF) powered by renewable electricity, and we foresee the application of direct reduced iron (DRI) technology using green hydrogen as the availability of this energy vector increases.
Additionally, we employ the Endless Strip Production (ESP) process, which combines casting and rolling in a single step, significantly reducing energy consumption and eliminating the use of natural gas. Our goal is to achieve true zero emissions, compared to approximately 1,800 kg per tonne of a conventional blast furnace.
Spain offers us a unique competitive advantage: some of the lowest renewable energy costs in Europe, abundant installed wind and solar capacity, and rapidly expanding green hydrogen infrastructure. Our renewable electricity will be sourced through long-term power purchase agreements (PPAs) and direct connections to nearby solar and wind farms. This approach not only benefits the environment but also reduces exposure to the volatility of fossil-fuel prices.
Circular economy by design
Our commitment to sustainability goes beyond carbon. From the design stage, we have conceived Hydnum Steel as a plant capable of optimizing every resource and minimizing waste to the greatest extent possible.
One of the most critical aspects is water management. Spain is a water-stressed country, and responsible steelmaking cannot ignore this reality. That is why we will use treated urban and industrial wastewater as our primary source. This water will pass through advanced filtration and recycling systems provided by Russula, a company specializing in industrial solutions. The result will be a near-100% reuse rate within our industrial process, drastically reducing freshwater withdrawal and eliminating effluent discharges, achieving a true zero liquid discharge model.
For solid residues, we have designed valorization processes that will allow by-products such as slag to be repurposed as construction aggregates, cement feedstock, or insulating materials. This circular approach fully aligns with the priorities of Europe’s green economy.
Digitalization: From day one
Hydnum Steel will be a digital plant from its fi rst day of operation. This is not a secondary feature, but a core principle of our operational design. By leveraging digital twins, advanced analytics, machine learning, and robotics, we will be able to optimize our processes in real time, reduce errors, improve energy efficiency, and maximize product quality.
Siemens’ digital-twin technology will allow us to simulate and fine-tune our processes virtually before going live, anticipating potential deviations and calibrating critical parameters. Our systems will be monitored around the clock, with predictive maintenance tools to prevent unplanned downtime, algorithms to optimize material and energy consumption, and automated control mechanisms that minimize production variability.
Moreover, automation will significantly enhance workplace safety by limiting worker exposure to high-risk environments and freeing up time for higher-value tasks. This transition does not eliminate jobs; it transforms them, making them more skilled, safer, and technology oriented.
A purpose-driven project designed to make an impact
The choice of Puertollano as the plant’s site is no accident. The city offers a prime logistical setting, with excellent rail and road connections, direct access to renewable energy, and a skilled, committed workforce. We are working closely with educational institutions such as the University of Castilla-La Mancha and vocational training centers to implement upskilling and retraining programs that prepare workers for the industrial jobs of the future.
Moreover, we are part of the Castilla-La Mancha Hydrogen Valley, in cooperation with the National Hydrogen Centre and other energy companies. This network of research, production, talent, and innovation is crucial to securing Europe’s future hydrogen supply under the transnational H2med project, positioning the region as a strategic hub for the energy transition and clean-technology development.
A model for Europe’s reindustrialization
Hydnum Steel is not an isolated initiative. It represents a new generation of European industry: clean, intelligent, and globally competitive. Europe faces the challenge of reindustrializing without repeating the mistakes of the past, committing to a decarbonized, resilient, and autonomous economy. Steel, as a fundamental material for infrastructure, transportation, renewable energy, and the green transition, must be at the heart of that strategy.
We are proving that decarbonization does not require sacrificing efficiency or profitability. On the contrary: clean, circular, and digitalized processes deliver greater resilience, improved performance, and a stronger competitive position in a world rapidly advancing toward ever more demanding standards.
A matter of strategic sovereignty
Finally, we must not forget that steel is a strategic resource. Its availability is crucial for the development of infrastructure, mobility, clean energy, and national defense. Increasing Europe’s capacity to produce its own clean flat steel means reducing external dependence, ensuring supply stability and strengthening industrial sovereignty in an increasingly geopolitically uncertain world.
In this sense, Hydnum Steel is more than an environmental or industrial project. It is a strategic investment in the future of Spain and Europe, rooted in sustainability, driven by innovation, and committed to a lasting positive impact.