The EU is the biggest importer of natural gas in the world, and although EU gas consumption is likely to remain stable up to 2030, many motivations to reduce the 400 billion cubic meters exist; among them the risks associated with resource dependency, the reduction in domestic production and the need to meet commitments to reduce emissions by 80-95% by 2050 in line with a global 2°C pathway.
With these objectives in mind, many potential solutions have been brought to the table, including the reduction in energy and heating demand through innovation and efficiency, and the replacement of natural gas with other energy forms in certain scenarios, including the use of biogas, gasified forestry biomass and other renewably produced gases such as hydrogen.
Combined with this is the fact that contracts for Russian gas end in 2025, and many uncertainties regarding the viability of further investments in conventional gas networks exist as governments and industry contemplate potentially increasing prices, reducing demand and the eventual goal of almost complete decarbonisation by 2050 or soon after.
Given these pressures and the resulting policy incentives since 2011 in the UK and France among other European countries, biogas production has risen from 2.2 Mtoe in 2000 to 15.6 Mtoe in 2016 now representing 4% of total European gas consumption. Many studies have been undertaken to find out what potential exists for biogas in Europe, and in light of recent industry growth, figures range from 9% to 16% of current natural gas demand by 2030, with some studies such as a 2012 DBFZ estimate citing a biomethane production potential of 98 billion cubic meters per year, equating to 25% of Europes natural gas demand without including energy crops or interseasonal cropping.
A recent Danish study conducted by the University of Aarlborg points to a potential of between 40 and 70 Mtoe using solely manure, straw and grass, depending on the availability of different types of feedstock/substrates within the EU, which amounts to between 9% and 16% of current natural gas usage before 2030 without compromising ecosystems and soil health. The upper range for this estimate (19%) does not factor in the wide range of additional substrates available for biogas production, and therefore validates the DBFZ figures from 2012.
The European Biogas Association (EBA) presents a more conservative forecast of 50 billion m3 (12.5% of current use) offset of current European natural gas demand by 2030, using a combination of biogas and biomethane derived from wood gasification. However, this figure may be revised upwards following the policy changes layed out in the revised Renewable Energy Directive, with a shift away from biofuels from energy crops with more focus on waste and forest residue utilisation.
The Danish study underlines the potential of basic agricultural residues, and this is echoed by Italian biogas producers who have developed a system of interseasonal cropping and digestate application to both maintain soil carbon and generate increased biogas potential through better practice. This system is being marketed as ‘Biogasdoneright®’ and is projected to amount to 12-13% of current Italian natural gas consumption by 2030.
Biogas production in the UK, France and elsewhere is also accelerating rapidly, with a number of options available to use better practices to increase production and maintain soil fertility using the nutrient-rich material remaining after the aneorobic digestion process.
A number of recent studies have also highlighted forestry residues and other lignocellulosic biomass in the production of biomethane as a sustainable and viable development of the biogas industry, in order to avoid emissions associated with energy crop use. Forestry-derived biomethane could contribute significantly to total biogas production given that EU policy under the revised Renewable Energy Directive has now dropped support for 1st generation biofuels and focused instead on second generation biofuel and biomethane production. Its expected that technical knowledge developed in the production of biofuels should be transferred to biogas/biomethane production, resulting in a reduced disruption to employment figures.
Given the vast array of feedstock available for biogas and biomethane production throughout Europe, the potential for growth is strong. Limitations to current biogas production where subsidised energy crops may result in increased emissions can be overcome by the use of biomass gasification, substitution of biofuels for biomethane, increased use of agricultural and municiple waste streams, and systems-approach best practices such as ‘Biogasdoneright®’.
Overall, the wide variety of liquid anaerobic digestion production methods including manure, grass, waste water & sewage treatment, residential organic waste collection and commercial waste food biomass, and dry biomass gasification through pyrolysis; including straw, municiple solid waste (MSW – landfill), forestry residues and waste-to-energy by-production (WDF), makes evaluating overall biogas potential difficult to accurately predict. However, given the scope for development in different regions throughout Europe, there is considerable cause for optimism within the industry.
The recent EU policy change with regards to biofuels can be seen as a reaction to the ongoing development of electric vehicles, which considerably reduces pressure on corn-based ethanol which makes up the majority of the biofuel production to date, and which has now been capped at 3.8% of the overall renewable energy target by 2030, down from 7%. Investment and jobs are expected to be transferred to advanced biofuel and biogas production, which emits far less GHGs and does not require imported feedstock such as palm oil being primarily derived from waste streams/solid biomass etc.