“Why biomethane is the UK’s best path to energy independence”

Dr Chris Mann, Co-founder and Chief Technology Officer of Bennamann, explains why biomethane is the UK's best pathway to a sustainable energy future.

With the UK committed to achieving net zero by 2050, the choice between different biofuel pathways will determine not just our carbon footprint, but our energy security and economic resilience. After years of developing biomethane solutions at Bennamann, I'm convinced that while ethanol may seem like the obvious choice, it's biomethane that holds the key to our sustainable energy future.

The methane imperative

The conversation around renewable fuels often misses a crucial point: methane capture isn't optional; it's essential for reaching net zero. Climate projections for limiting warming to 1.5°C by 2050 frequently assume significant methane removal from the environment. Without addressing methane emissions, net zero becomes mathematically impossible.

The UK produces approximately 90 million tonnes of livestock waste (slurry and manure) annually, yet only 3% is currently managed for methane capture. This represents a staggering waste of both environmental opportunity and energy potential.

When we capture this fugitive methane and convert it to biomethane, we achieve something remarkable: negative carbon emissions. California Air Resources Board Low Carbon Fuel Standard data shows biomethane from waste can achieve carbon intensity scores of -300 to -400 compared to diesel's baseline of 100. Ethanol, by contrast, rarely drops below zero on the same scale.

Ethanol's hidden environmental cost

The production process for ethanol creates waste streams that generate significant methane emissions. You cannot have sustainable ethanol without capturing the methane from ethanol production; making biomethane an unavoidable component of any ethanol strategy.

Ethanol production also requires intensive agriculture, competing directly with the demands of food security. We've seen the devastating effects in places like Australia, where sugar cane production for ethanol has contributed to Great Barrier Reef pollution through agricultural runoff. The UK cannot afford to repeat these mistakes by prioritising crop-based biofuels over waste-derived alternatives.

The land use argument is compelling: why dedicate productive agricultural land to fuel crops when we have millions of tonnes of organic waste that could be converted to energy instead?

The infrastructure advantage

One of biomethane's most overlooked advantages is infrastructure flexibility. We can create distributed energy networks that bypass grid constraints entirely. A single farm can become a fuel station, producing compressed biomethane on-site for local vehicle fleets. With 8,353 petrol stations (as of 2023) serving the entire UK; this is fewer than the number of dairy farms at around 10,825 dairy farmers according to Dairy UK, as such, a distributed approach could rapidly scale renewable fuel access. Capturing methane from a single farm's waste and using it to power one tractor is equivalent to removing the carbon emissions of 100 households. Now imagine scaling this across the UK's thousands of dairy farms.

Biomethane offers something ethanol cannot: true energy independence. Currently, out of the total renewable fuel used in the UK in 2023, only nine per cent was made from raw materials (feedstocks) that were grown or sourced within the UK, making us vulnerable to global market volatility and supply chain disruptions. Biomethane from agricultural waste is inherently local, keeping energy pounds in rural communities and creating genuine economic resilience.

This distributed energy model also enables rural economic growth. Farms become energy producers, selling fuel to local transport operators and providing EV charging powered by their own biogas. It's a complete reimagining of rural economies, where every village could theoretically achieve carbon neutrality through its surrounding agricultural activity.

Policy recommendations for rapid deployment

The UK government must act decisively to prioritise biomethane. Three critical policy shifts would accelerate adoption:

First, acknowledge the true scale of agricultural methane emissions. Current government figures dramatically underestimate methane production from slurry; reporting 38kg of methane produced per cow annually when the reality is 145-198kg. Without honest accounting, we cannot design effective capture policies.

Second, implement a scrappage scheme for diesel tractors and heavy vehicles over 3.5 tonnes. This creates immediate demand for biomethane-powered alternatives while removing polluting vehicles from our roads. With no viable electric alternatives for heavy agricultural and transport applications, biomethane fills a critical gap.

Third, expand grant schemes beyond grid-connected anaerobic digesters to include small-scale, distributed biomethane production. The current obsession with grid injection limits our ability to create local circular economies where waste becomes fuel on-site.

Additionally, the Government must support farmers to both upgrade and seal their slurry stores, which hold the farm manure. By doing so, this prevents run-off and overflow and so will help protect our rivers, soils and seas from contamination. This also prevents ammonia loss into the atmosphere and reduces the need and reliance on artificial fertiliser derived from fossil fuels.

The scale of opportunity

The numbers are compelling. Beyond the 90 million tonnes of dairy waste, we have vast untapped potential in grass waste; golf courses alone generating millions of tonnes of organic matter. Add roadside verges, park maintenance and other grass waste streams, and we're looking at energy potential that dwarfs our current biofuel production.

This isn't just about replacing fossil fuels; it's about creating a new energy paradigm where waste becomes wealth, rural communities become energy hubs, and environmental protection drives economic growth.

While ethanol offers a familiar path forward, biomethane represents a quantum leap in sustainable energy thinking. It solves multiple challenges simultaneously: reducing potent greenhouse gas emissions, creating energy independence, using existing infrastructure and generating rural economic opportunities.

The UK stands at an energy crossroads. We can continue down the well-trodden ethanol path, competing with food production and creating new environmental challenges. Or we can embrace biomethane's revolutionary potential, turning our waste streams into energy security and our farms into the foundation of a truly sustainable energy future.