Biogas vs Natural Gas

Biogas and natural gas are both methane-based fuels used across the UK for heating, electricity generation and industrial processes. However, they differ significantly in origin, environmental impact and long-term sustainability.

As the UK works toward its legally binding Net Zero by 2050 target, renewable gases such as biomethane are increasingly discussed as part of the country’s low-carbon energy transition.

This guide explains the difference between biogas and natural gas, with a focus on the UK energy system.

What Is Natural Gas?

Natural gas is a fossil fuel formed from organic matter buried underground millions of years ago. It is extracted through drilling and transported through the UK’s gas transmission and distribution network.

It consists primarily of methane (typically over 85–90%) and is valued for its high energy density and flexible use across heating, electricity generation and manufacturing.

Natural Gas in the UK

Natural gas plays a central role in the UK energy mix:

• 🇬🇧 Gas provides approximately 30–35% of the UK’s primary energy supply.¹
• 🇬🇧 Around 85% of UK homes use gas central heating.²
• 🇬🇧 Gas-fired power stations continue to support electricity generation, particularly during peak demand or low renewable output.¹

Globally, natural gas accounts for around 24% of total primary energy demand.³

Environmental Impact of Natural Gas

When combusted, natural gas produces:

• Around 40–45% less CO₂ than coal
• Around 25–30% less CO₂ than oil³

However, it still emits carbon dioxide, and methane leakage during production and transport is a concern. Methane has a global warming potential approximately 28 times greater than CO₂ over 100 years.⁴

Importantly, natural gas is non-renewable, meaning its use releases fossil carbon that has been stored underground for millions of years.

What Is Biogas?

Biogas is a renewable gas produced through anaerobic digestion (AD), a biological process in which microorganisms break down organic material in the absence of oxygen.

Typical UK feedstock include:

• Agricultural waste and slurry
• Food waste
• Sewage sludge
• Organic industrial residues

Raw biogas usually contains 50–70% methane, with most of the remainder being carbon dioxide.⁵

When upgraded to remove carbon dioxide and impurities, it becomes biomethane, a grid-quality renewable gas that can be injected directly into the UK gas network.

Biogas and Biomethane in the UK

The UK has developed a growing anaerobic digestion and biomethane sector:

• 🇬🇧 There are 700+ anaerobic digestion plants operating across the UK.⁵
• 🇬🇧 Biomethane is already being injected into the gas grid under schemes such as the Green Gas Support Scheme (GGSS).⁶
• 🇬🇧 The Climate Change Committee recognises biomethane as contributing to Net Zero pathways, particularly in hard-to-electrify sectors.⁷

Globally, the International Energy Agency (IEA) estimates that sustainably produced biogas and biomethane could potentially meet up to 20–25% of current global natural gas demand if fully developed.³
(This reflects technical potential rather than current output.)

Environmental Comparison: Biogas vs Natural Gas

The key difference lies in the carbon cycle.

• Natural gas introduces fossil carbon into the atmosphere.
• Biogas recycles carbon already present in the modern biosphere.

When produced from waste materials, biomethane can deliver significant lifecycle greenhouse gas savings compared to fossil gas.³

Additionally, capturing methane from decomposing organic waste prevents it from being released directly into the atmosphere, an important climate benefit given methane’s high warming potential.⁴

Technical Comparison at a Glance

From a practical standpoint, upgraded biomethane is chemically similar to natural gas, meaning it can:

• Be injected into the existing UK gas grid
• Fuel domestic boilers and CHP systems
• Power heavy goods vehicles (Bio-CNG)
• Support industrial heat demand

This infrastructure compatibility makes renewable gas particularly relevant in the UK, where gas heating is widespread.

The Role of Renewable Gas in the UK Energy Transition

Natural gas currently remains essential for UK energy security. However, long-term decarbonisation requires reducing reliance on fossil fuels.

Renewable gases such as biomethane:

• Support decarbonisation of heating
• Provide dispatchable and storable energy
• Contribute to circular waste management
• Reduce methane emissions from organic waste

Rather than fully replacing natural gas in the short term, biomethane is increasingly viewed as a transitional and complementary solution within a diversified low-carbon UK energy mix.

Conclusion

For UK households and businesses, understanding the difference between biogas and natural gas is key to navigating the energy transition.

Natural gas remains a dominant part of the UK energy system, but it is fossil-based and finite.
Biogas and biomethane, by contrast, offer a renewable, lower-carbon alternative that can integrate with existing gas infrastructure.

As the UK moves toward Net Zero by 2050, renewable gas is expected to play a growing role in balancing energy security with emissions reduction.

Sources

1. Department for Energy Security & Net Zero (DESNZ), UK Energy in Brief 2023.
2. Ofgem, Domestic heating statistics and fuel mix data.
3. International Energy Agency (IEA), World Energy Outlook and Outlook for Biogases.
4. Intergovernmental Panel on Climate Change (IPCC), AR6 Climate Change 2021 – Global Warming Potentials.
5. Anaerobic Digestion and Bioresources Association (ADBA), UK industry statistics.
6. UK Government, Green Gas Support Scheme (GGSS) policy guidance.
7. Climate Change Committee (CCC), Sixth Carbon Budget & Net Zero pathway reports.