On October 9, 2025, two major developments on separate continents underscored the accelerating global push toward renewable energy and a circular economy. In Spain, Uniper, a leading German energy company, inked a seven-year biomethane purchase agreement with Five Bioenergy, a Spanish developer renowned for its large-scale projects. Meanwhile, in India, Clarke Energy—a Rehlko company—commissioned its first membrane-based biogas upgrading plant at a municipal solid waste site in Chennai, marking a significant leap for the country’s clean energy ambitions.
Both milestones reflect a growing international consensus: renewable gases like biomethane are no longer niche experiments but have become central to decarbonizing energy systems and industries worldwide. The details of these projects reveal not only technical innovation but also a deepening collaboration between public and private sectors across borders.
According to a joint statement from Uniper and Five Bioenergy, the new agreement will secure biomethane supplies from three of Spain’s largest plants, all located in Murcia. The deal is designed to complement the expanding share of renewables in Europe’s energy mix with low-carbon sources, specifically targeting the decarbonization of road and maritime transport sectors. Uniper, which has been steadily broadening its portfolio to include hydrogen, its derivatives, and biomethane, sees this agreement as a pivotal step toward a sustainable future.
Carsten Poppinga, Chief Commercial Officer of Uniper, emphasized the significance of the partnership: “We are very proud to partner with the leading Spanish biomethane developer, Five Bioenergy. The supply agreement underscores our ambition to expand and diversify our low-carbon energy portfolio. By sourcing high-quality biomethane, we are not only strengthening our supply sources but also advancing the decarbonization of our operations. We look forward to a productive and innovative partnership with Five Bioenergy and to realizing new low-carbon opportunities together that will help to create a cleaner and more resilient energy future.”
For Five Bioenergy, the agreement represents a major commercial and strategic milestone. Ivan Copin, the company’s Chief Investment Officer, noted, “This collaboration with Uniper validates our strategy of merging cutting-edge technology with industrial-scale production. It secures a stable market for our biomethane while reinforcing our vision of a decarbonized Europe powered by renewable energy. Far more than a commercial deal, this partnership is a decisive catalyst for accelerating the energy transition and advancing a circular economy.”
While Europe’s energy transition is gaining momentum, similar advances are unfolding in Asia. In Chennai, Clarke Energy’s new biogas upgrading facility—fully designed, developed, and manufactured in India—has begun operations at a municipal solid waste anaerobic digestion site managed by Srinivas Waste Management Services Private Limited (SWMS). This project arrives at a critical time, as India’s SATAT (Sustainable Alternative Towards Affordable Transportation) initiative aims to establish 5,000 bio-CNG plants nationwide, transforming organic waste into clean, renewable fuel.
The SWMS site processes biodegradable food waste from the surrounding region, converting it into biogas and a soil improver, delivering tangible sustainability benefits to the local community. Clarke Energy’s membrane-based upgrader replaces a traditional pressure swing adsorption (PSA) system, offering a scalable and efficient solution capable of upgrading 600 Nm³/hr of raw biogas into high-purity biomethane. Initial commissioning results have been promising, with methane purity levels exceeding 97.4% and minimal methane losses—a crucial benchmark for operational efficiency and environmental impact.
Kyle Quinn, President of Clarke Energy, highlighted the significance of this milestone: “This project marks the first biogas upgrader system fully designed, developed, and manufactured in India by Clarke Energy. It’s a significant milestone for our Indian operations by demonstrating how we’re combining international expertise with local execution to deliver state-of-the-art renewable gas solutions that support India’s clean energy future.”
Clarke Energy’s approach is notable for its focus on local manufacturing and supply chains. Key components of the new system—such as the biogas dryer, scrubber, low-pressure compressor, and two-stage membrane separation system—were sourced locally, ensuring competitive delivery timelines and reinforcing the sustainability of the project. Unlike conventional PSA systems, the membrane-based upgrader offers higher methane recovery, potentially lower operational costs, and modular scalability, making it especially well-suited for urban waste-to-energy applications.
The commissioning of this plant was timed to coincide with a UK-India trade delegation visit, underscoring the importance of international cooperation in advancing clean energy technologies. Clarke Energy, which has operated in India for three decades and installed nearly 2 GW of low-carbon, renewable power across India and Bangladesh, continues to expand its portfolio of biogas upgrading projects not only in India but also in France and the United States. The company’s integrated solutions include carbon dioxide recovery from biogas upgrading and hydrogen production technologies, supporting industrial decarbonization and the transition to a circular economy.
Rehlko, Clarke Energy’s parent company, plays a strategic role in driving the development of high-impact, regionally tailored clean energy solutions. As a global leader in energy resilience, Rehlko’s portfolio includes Power Systems, Home Energy, Kohler Uninterruptible Power, and Engines, alongside Clarke Energy. This breadth allows Rehlko to deliver power solutions where and when the grid cannot, with a strong emphasis on innovation, quality, and long-term customer support.
On the ground in Chennai, SWMS exemplifies the promise of circular economy models. Founded in 2003, SWMS has emerged as one of South India’s leading integrated waste management companies, handling everything from collection and transportation to processing, recycling, and safe disposal. Its flagship 100 TPD Bio-CNG plant turns organic waste into compressed biogas (CBG), providing a renewable alternative to fossil fuels and supporting India’s broader clean energy ambitions.
These developments in Spain and India are more than isolated success stories. They reflect a broader trend: the integration of renewable gases into mainstream energy systems, the localization of advanced technologies, and the growing importance of public-private partnerships in tackling climate change. Both Uniper’s and Clarke Energy’s projects demonstrate that decarbonization is not just about reducing emissions—it’s also about building resilient, flexible energy infrastructure that can adapt to evolving economic and environmental challenges.
As nations race to meet ambitious climate targets, the lessons from Murcia and Chennai resonate far beyond their borders. Investment in biomethane and biogas upgrading technologies, coupled with robust international collaboration, is paving the way for a cleaner, more sustainable—and ultimately more circular—global energy future.