In April 2025, a massive blackout left millions of people in Spain, Portugal and southern France without electricity for more than ten hours. The outage affected rail transport, paralysed data centres and cut power to public and private buildings, highlighting how a grid failure can have repercussions at multiple levels. It was not an isolated incident: in June 2024, a voltage collapse caused a widespread blackout in the Balkan region, leaving Albania, Montenegro, Bosnia-Herzegovina and Croatia without power. A year earlier, in 2023, an ice storm in Canada brought down thousands of power lines, disrupting supply to over a million people and forcing hospitals, water treatment plants and emergency services to operate for days solely on backup systems.

Adequate reserves and priority replenishment contracts are part of any business continuity strategy.

These kinds of events demonstrate that critical infrastructure such as hospitals, data centres, transport systems or control hubs cannot afford power outages without compromising safety, the economy and, in many cases, human lives. Ensuring their continuous operation requires solutions that combine reliability, rapid response and operational autonomy. In this context, distributed generation emerges as an essential tool: it enables energy production closer to the point of consumption, reduces dependency on the grid, and increases resilience and capacity to anticipate failures or external disruptions—an area in which Genesal Energy has solid experience developing bespoke solutions for strategic sectors.

Distributed Generation as a High-Availability Solution

Producing electricity at the point of consumption—or in its immediate vicinity—offers decisive advantages in environments where service continuity is non-negotiable, from reducing transmission losses to enabling island mode operation and tailoring technology to the specific characteristics of each facility. These systems therefore strengthen the ability to respond instantly to any interruption.

In critical infrastructure, backup systems are usually based on diesel or gas gensets, often combined with energy storage and, increasingly, with renewable generation. These configurations are designed to come online within seconds of detecting a failure and, in particularly sensitive applications, incorporate N+1 redundancy: an additional unit capable of carrying the full load if the main unit goes out of service.

Ensuring stable operation over extended periods requires attention to factors such as fuel storage capacity, engine efficiency, and the thermal and acoustic management of the installation. In hospital environments, for instance, it is common to install tanks that guarantee at least 48 hours of autonomy and control systems that prioritise power to essential areas, thereby ensuring continuous availability during crises.

Design and Operation: Key Factors

The starting point for any distributed backup generation system is a detailed analysis of the critical load. This defines which equipment must remain powered, the maximum expected demand during peak periods, the duration for which supply must be maintained, and the appropriate level of redundancy. A medium-sized hospital, for example, may concentrate most of its critical load in operating theatres, intensive care units and climate control systems for sensitive areas, with demands exceeding one megawatt of power.

These systems therefore strengthen the ability to respond instantly to any interruption.

Planned maintenance is a key factor in ensuring availability. It includes periodic inspections of starting systems, monitoring battery condition, checking electrical connections and verifying fuel quality. In critical installations, these tasks are reinforced with regular live load tests to confirm switching times, voltage and frequency stability, and coordination with other electrical systems. Increasingly, remote monitoring and predictive maintenance are integrated—tools that Genesal Energy employs to anticipate incidents and optimise operation.

Integration with Renewables and Storage

Integration with renewable sources and storage is becoming increasingly common. A hybrid system combining solar PV, batteries and a genset can optimise fuel consumption and extend autonomy, particularly useful in situations of prolonged isolation.

Coordination between these sources is managed by control systems that prioritise efficiency while guaranteeing power availability at all times. This strategy not only reduces emissions but also helps extend the service life of thermal units by reducing idle or low-load operating hours. In line with its sustainability commitment, Genesal Energy incorporates ecodesign-certified solutions (ISO 14006) and alternative fuels such as HVO, which can cut the carbon footprint by up to 90% compared to fossil diesel.

Challenges and Opportunities in the Spanish Context

The deployment of distributed generation solutions for backup in critical infrastructure in Spain faces several challenges. One is updating regulations to facilitate the integration of renewables and storage while maintaining the required reliability standards. Another is the modernisation of the installed fleet: many units currently in operation consume more fuel and emit more than today’s technologies. In some cases, replacing them with more efficient models can reduce specific consumption by over 15% and improve dynamic response to sudden load changes.

Fuel supply logistics is another key factor. Adequate reserves and priority replenishment contracts are part of any business continuity strategy. In urban environments, space limitations or environmental restrictions can affect storage capacity, driving the adoption of solutions such as external modular tanks or low-emission fuels like HVO.

Overcoming these challenges will not only strengthen resilience but also advance decarbonisation and energy independence. Genesal Energy’s experience shows that the most effective solutions combine proven technology with meticulous planning in operation, logistics and maintenance, ensuring the operational continuity of critical installations while aligning with the objectives of the energy transition.

On the anniversary of the adoption of the Sustainable Development Goals, it is timely to review how strategic technologies such as gensets are being transformed to align with the 2030 Agenda. The transition towards a low-carbon economic model, reflected in goals such as SDG 7 (affordable and clean energy), SDG 9 (industry, innovation and infrastructure), SDG 12 (responsible consumption and production) and SDG 13 (climate action), is radically reshaping the framework in which distributed generation technologies operate. The increasing penetration of renewable sources such as wind and solar power adds complexity to the electricity system and raises resilience requirements. In this context, emergency gensets—traditionally regarded as marginal backup equipment—are becoming a critical element for energy security and operational continuity.

Decarbonisation of the sector must therefore be based on three main pillars: the gradual substitution of fossil diesel with renewable fuels, the development of hydrogen-based solutions, and the application of circular economy principles in design and manufacturing.

Their role is crucial in hospitals, data centres, telecommunications, transport and essential services, where they ensure supply in the event of grid failure. Although their annual operating time is limited—around ten hours on average in Europe, including periodic testing—and therefore their cumulative impact is small compared to other generation sources, achieving a climate-neutral economy aligned with the SDGs also requires these units to evolve. For this reason, the industry is working on the incorporation of renewable fuels, hydrogen-based solutions and ecodesign principles, so that gensets can maintain their strategic role while effectively reducing their environmental footprint.

Regulatory Framework: Stage V and the Outlook for Stage VI

Current EU legislation on emissions for internal combustion engines intended for non-road mobile machinery is mainly based on Regulation (EU) 2016/1628, known as Stage V. Its implementation, phased in between 2019 and 2021 depending on power ranges, broadened the spectrum of regulated capacities and substantially tightened the emission limits for NOx, particulates (PM), hydrocarbons (HC) and carbon monoxide (CO).

Stage V introduced the general requirement to use after-treatment technologies such as selective catalytic reduction (SCR), diesel oxidation catalysts (DOC) and diesel particulate filters (DPF). It also imposed the use of advanced electronic control systems, differential pressure sensors and emission monitoring through OBD (On-Board Diagnostics) in certain power ranges. For the mobile genset sector, this framework has entailed a comprehensive redesign of engines, combustion systems and control architectures, with a significant increase in technical complexity and production and maintenance costs.

On the anniversary of the Sustainable Development Goals, it is worth remembering that Europe’s energy transition requires massive electrification and deployment of renewables, but also resilience against intermittency and growing grid stress.

In parallel with the implementation of Stage V, the European Commission and sectoral bodies have opened the debate on a future Stage VI. This new phase is not conceived as a one-off adjustment but as the natural evolution of a regulatory framework aimed at supporting the decarbonisation of the European economy.

The outlook for Stage VI points to several areas of development:

• Application differentiation. A specific regulatory framework is being considered for emergency gensets (limited use, up to 200 hours per year) as opposed to continuous-use units.
• Real-world operating conditions. The introduction of tests reflecting in-field engine performance is under discussion, similar to RDE testing in the automotive sector.
• Compatibility with alternative fuels. Stage VI is expected to acknowledge the growing availability of advanced biofuels and the development of hydrogen applications, incorporating these vectors into compliance schemes.

Thus, the transition from Stage V to Stage VI will not only tighten emission limits but also redefine classification and approval procedures, forcing manufacturers and users to anticipate R&D investments and plan the technological transition of their fleets. This increasingly demanding framework should not be seen merely as a regulatory challenge, but as the catalyst for a broader transformation: the technological evolution of the sector towards a low-emission model. At this stage, the industry’s response goes beyond optimising after-treatment technologies and is directed towards effectively reducing the carbon footprint through renewable fuels, the development of hydrogen-based solutions, and the integration of ecodesign principles in the design and manufacture of equipment.

Sector Decarbonisation: Alternative Fuels, Hydrogen and Ecodesign

Decarbonisation of the sector must therefore be based on three main pillars: the gradual substitution of fossil diesel with renewable fuels, the development of hydrogen-based solutions, and the application of circular economy principles in design and manufacturing. Together, these provide a technological framework that enables emission reductions without compromising start-up reliability, ensuring supply availability in critical environments while anticipating future European regulatory demands.

Among the available solutions, advanced biofuels—particularly hydrotreated vegetable oil (HVO)—represent the most mature alternative for reducing the carbon footprint of both existing fleets and new units. HVO is a synthetic paraffinic fuel, compliant with EN 15940, that can be used in most modern diesel engines without technical modifications. It allows lifecycle CO₂ emission reductions of up to 90%, due to its biogenic origin, and offers additional advantages: it contains no sulphur or aromatics, provides cleaner combustion, delivers 10–18% lower emissions of particulates and NOx in tests, and has remarkable storage stability of up to ten years. From an operational standpoint, it integrates seamlessly into logistics without compromising start-up reliability in critical applications, making it the most immediate lever to advance decarbonisation.

The industry is working on the incorporation of renewable fuels, hydrogen-based solutions and ecodesign principles, so that gensets can maintain their strategic role while effectively reducing their environmental footprint.

Gas engines and dual-fuel applications offer an intermediate option in terms of reducing local emissions and diversifying energy sources. Their deployment, however, depends on the availability of supply infrastructure, which limits their use in applications where security of supply is critical. Even so, developments that enable operation with gas–diesel blends, or with hydrogen additions, open up new transitional pathways to cleaner solutions.

Looking further ahead, green hydrogen is emerging as the reference energy vector for the full decarbonisation of the sector. Pilot projects of gensets running entirely on hydrogen, as well as dual-fuel applications combining diesel and hydrogen, are already being validated by several European manufacturers. Although technical feasibility has been demonstrated, significant challenges remain in terms of production costs, engine durability, energy density and, above all, safe storage and distribution of the gas. In the medium term, hydrogen is considered a realistic solution in environments where it can be produced on-site by electrolysers coupled to renewable sources, as is already happening in certain industrial projects and strategic data centres.

Finally, ecodesign and the circular economy complete this strategy. More than 70% of a genset’s mass is currently recyclable thanks to the predominance of metals such as steel, copper and aluminium, and with improvements in design and manufacturing processes this figure can exceed 90%. Added to this is the long durability of these units: with proper maintenance, their service life can easily surpass three decades, allowing the impact of manufacturing to be amortised over a wide time horizon. In parallel, certifications such as ISO 14006 incorporate environmental criteria into the design phase, ensuring that products are conceived with a circular approach. Genesal Energy, the first company in the sector to obtain this certification, exemplifies how sustainability can be integrated into technological development strategies and deliver competitive advantages in markets with increasingly stringent environmental requirements.

When environmental performance is analysed from a lifecycle perspective, emergency gensets appear far more sustainable than often assumed. Their short operating times naturally limit cumulative emissions; the adoption of biofuels such as HVO drastically cuts their carbon footprint; and ecodesign maximises their circularity and efficiency. With these improvements, gensets reinforce their alignment with the EU’s circular economy objectives and consolidate an increasingly favourable environmental profile.

Conclusion

On the anniversary of the Sustainable Development Goals, it is worth remembering that Europe’s energy transition requires massive electrification and deployment of renewables, but also resilience against intermittency and growing grid stress. In this balance, gensets are irreplaceable: their limited operating time restricts environmental impact, while their role in ensuring the continuity of critical services is decisive.

Looking further ahead, green hydrogen is emerging as the reference energy vector for the full decarbonisation of the sector.

The Stage V framework has already marked a milestone in emission reduction, and the forthcoming Stage VI will pave the way for the integration of renewable fuels and hydrogen-based solutions, complemented by advances in biofuels such as HVO and in ecodesign.

Decarbonisation in industry is not just about technology: it’s about acknowledging operational complexity and the need to combine multiple solutions. Genesal Energy knows this well. That’s why we chose to take action.

Our renovation of units B27 and B28 at the Bergondo industrial estate (A Coruña) is a real example of how to integrate concrete, measured, and coordinated efforts to move towards a more sustainable industry.

Producing renewable energy is not enough, you also need to manage it properly.

In recent years, we’ve taken an active role in the energy transition, convinced that decarbonising our processes is not a choice but a responsibility. However, we are under no illusion: the path is not easy. Challenges are high energy consumption, demanding technical processes, and above all, the need to ensure uninterrupted operational continuity. We understand there is no single solution or magic formula. Every industry is different, and every step matters.

In our case, the first step was analysis. We studied our energy consumption, losses, thermal demand, and the renewable potential of our facilities in depth. Based on that data, we designed an intervention around four pillars:

• Integration of renewable energy
• Smart energy management
• Recovery of energy flows
• Overall efficiency improvement

For renewable generation, we chose to integrate the solution into the architecture of our buildings. We installed 111 sq metres of photovoltaic glass with a capacity of 13.1 kWp directly into the façades, allowing us to generate clean energy while also improving thermal insulation. This was complemented by a 252 m² photovoltaic roof (57.3 kWp) on unit B27. Thanks to these installations, we now cover 100% of the energy consumption of both units during peak solar hours.
But producing renewable energy is not enough, you also need to manage it properly. That’s why we incorporated the OGGY, an advanced energy storage and management system that monitors usage in real time and automatically determines the most efficient use of the available energy. This system helped us reduce consumption by 27% in just one year.

There is no single solution or magic formula. Every industry is different, and every step matters.

We went one step further: we began recovering the energy generated during genset testing (FATs). Thanks to its integration with OGGY, that energy is fed back into the system, further reducing our dependence on the electricity grid.

The results came quickly: in the first year, we avoided more than 23 tonnes of CO₂ equivalent emissions. Our facilities also improved their energy certification, moving from a rating of “E” to “B”. An improvement that reflects not just efficiency, but a genuine commitment to sustainability.

This project has shown us that industrial decarbonisation is not achieved through isolated grand gestures, but through concrete, measurable, and coordinated actions. It requires vision, strategy, and the ability to adapt solutions to the specific needs of each operation. And above all, it requires commitment.
Genesal Energy is clear on this: we’ll keep moving forward.

Author: Antía Míguez Fariña, Sustainability Coordinator, Genesal Energy