By Dr Chris Mann, Co-founder and CTO at Bennamann
My journey to agricultural innovation began in polluted waters off the Welsh coast. As a surfer since the mid-1980s, I regularly braved the toxic brown waters of Porthcawl, near Port Talbot, where industrial waste and raw sewage created conditions so hazardous that ear and nose infections were routine consequences of pursuing my passion.
The water there was genuinely toxic. Despite the obvious health risks, the draw of surfing proved irresistible, leading me to become an early member of Surfers Against Sewage, an organisation that successfully campaigns for cleaner coastal waters.
As human waste management improved through the 1990s and 2000s, I noticed a disturbing new pattern emerging. After heavy rainfall, rivers would turn brown but this time it wasn’t due to human sewage. It was agricultural runoff from intensive farming operations, carrying animal waste and soil from fields left bare throughout the winter.
I didn’t see this in the 1980s because we didn’t have intensive farming on the same scale. Most dairy farms were still small family-run operations with a hundred to three hundred cows; the upper limit for what a family could milk morning and evening. The shift to larger-scale operations, combined with changing weather patterns, had created a new environmental challenge that would capture my attention as both a physicist and environmental observer.
The Florida revelation
My eureka moment came during a business trip to Florida while working in the security industry. While being driven to the airport, a local radio announcement warned residents not to cut their grass and bag it before going away for weekends, as the bags could explode in garage heat.
The explanation my host provided was both alarming and illuminating. Homeowners, constrained by strict lawn maintenance rules, would cut grass on Thursday nights before weekend trips, storing it in black plastic bags in garages that heated up to 50°C by air conditioning units. The grass would decompose, producing biogas and methane, causing the bags to expand and potentially explode when residents returned and switched on the lights.
I just thought, “Wow, that’s a lot of energy.” This chance encounter introduced me to biogas generation from organic waste; knowledge I had no previous exposure to despite my physics background. When I returned home, I shared this revelation with Mike Bennett, who would become my co-founder at Bennamann, and we started researching the potential.
From space to agricultural innovation
My expertise in applied physics had been honed through years working with NASA and the European Space Agency, developing sensors for remote sensing satellites that monitored global warming indicators like sea surface temperature. My speciality in cryogenics, managing extremely cold temperatures for space applications, would prove unexpectedly crucial to agricultural innovations.
The connection became clear when I discovered a Chinese biogas manual, documenting a 1970s programme that installed over 30 million small-scale anaerobic digesters across rural China. These simple systems converted village waste into cooking fuel, preventing deforestation while providing sustainable energy.
I realised that while generating methane from waste was straightforward, storing and transporting it presented significant challenges. Biogas is difficult to store, compressed methane requires heavy cylinders, but liquid methane, which demands cryogenic technology, offered the highest energy density and portability.
That’s where the light bulb went on in my head. The technology in the space industry could solve methane storage challenges, making farm-generated fuel as portable and practical as fossil fuels. Methane is essentially rocket fuel and I had the expertise to handle it safely and efficiently.
The Bennamann solution
Co-founding Bennamann in 2011 with Mike Bennett, we set out to create practical solutions for farm waste management. Our first breakthrough was the Smartcover system, covers for slurry lagoons that capture methane while preventing rainwater contamination and reducing fertiliser costs by around 50-60%.
From a farmer’s perspective, the benefits extend far beyond energy generation. Our covers pay for themselves by meeting legal requirements for slurry storage and reducing spreading costs. We’ve seen 50-60% reductions in fertiliser requirements and reductions in protein feeds for animals. The product becomes high-value because it’s low-carbon, with farmers already accessing premium markets.
Bennamann’s most revolutionary innovation is the Biocycle™, a mobile upgrading system that transforms the economics of small-scale anaerobic digestion. Rather than installing expensive equipment on individual farms where it would sit idle most of the time, the Biocycle operates on a service model, processing a week’s worth of biogas from multiple farms in just 24 hours.
When we first looked at small farms, we realised that if a farmer bought upgrading equipment and put it on his site, he would only get about a fifth of the use from it; it would sit idle for five days out of six. By making it mobile, the cost of the equipment is spread across five or six farms, bringing the return on investment down from 15 years to three years.
The Biocycle had to be incredibly low cost, really small, mobile, and extremely reliable because it’s driven around on trucks and trailers. We also had to design it for mass production because we need to make thousands of them. This set the bar very high for development, but we’ve been fortunate to receive support from the UK government, European Union and Cornwall Council.
The Biocycle fills a unique niche for existing anaerobic digestion plants that generate electricity from biogas but have no way to upgrade to biomethane for grid injection because they lack the necessary connections.
We can literally place our equipment next to an AD plant, take an additional 10-15% on what they would normally be able to convert and then either convert it into vehicle fuel or store the gas for further sale and transformation outside the farm. The system is up and running in a couple of days, versus building permanent infrastructure which involves civil engineering and takes months.
The climate imperative
Agriculture accounts for 49% of all methane emissions in the UK, according to 2022 Government data. The scale of this challenge becomes clear when you consider that methane is 84 times more potent than CO2 over a 20-year period. The UK has committed to the Global Methane Pledge, requiring a 30% reduction in methane emissions from 2020 levels by 2030. Without capturing agricultural methane, reaching net zero becomes impossible.
The transformation potential extends far beyond farming. Every council managing roadside verges, every school with playing fields, every golf course – all generate organic waste that could fuel our distributed energy network. My vision is for small anaerobic digesters in every location in which organic waste is generated, with weekly collections of liquid methane, creating energy independence at a local level.
Countries worldwide are asking how they can access this technology sooner. The UK has become a world leader in biomethane applications, with the New Holland methane tractor representing cutting-edge innovation we can already export globally. With the burst of electrical machines and vehicles, storing biomethane to generate EV charging functionalities off the grid will support reducing even further the major pollution source of transportation. As well as this, biomethane powering electrical vehicles off grid lowers the necessary public infrastructure investments.
This represents a completely new economic sector, opening farming to new equipment, technologies and revenue streams. What started with sewage runoff and exploding grass bags has evolved into a solution that could transform how we think about waste, energy and agricultural sustainability.