The push to develop a farm-led anaerobic digestion (AD) sector in Ireland continues and the feeling among those in the industry is that it’s now or never. Over the coming decade, if we don’t see the development of the sector in a meaningful way, then it’s questionable if it will ever happen.

Having written about AD in Ireland extensively, the message hasn’t changed. AD is a natural fit for Ireland given our large livestock industry and the availability of manures, as well as our ability to grow feedstock competitively.

Furthermore, given the mounting pressure on the entire agricultural sector to decarbonise, coupled with our continued failure to meet our renewable transport and heat targets, AD can provide a real solution to help solve these challenges.

What is so attractive about AD is that farmers are at the heart of the sector and, based on examples from other countries, including Northern Ireland, it can provide a real opportunity for income diversification.

Digestate will become a valuable organic biofertiliser in the coming years.

This is in stark contrast to the country’s flagship Renewable Electricity Support Scheme (RESS), where farmer engagement is only seen as a means to asset development.

While there are many challenges associated with developing an AD sector, chiefly to do with funding sources, there are a number of credible solutions put forward by industry on how to do this.

What is even more puzzling about why the sector is lagging behind is that Ireland has officially been recognised by the European Commission as having the largest potential to produce biomethane in Europe.

The Commission estimates that 20% of current natural gas demand could be substituted with biomethane by 2030, if the correct supports are put in place. But still the Government continues to drag its feet.

But the purpose of this article isn’t to dwell on Ireland’s lack of progress in the sector. Instead, we will delve into the progress made and the future plans for AD in other European countries.

European state of play

AD is a well-established technology in many European countries. Around 19,000 AD plants are in operation around Europe, producing 167 terawatt hours (TWh) of biogas.

The vast majority of these plants are producing biogas for combustion to generate renewable electricity and are receiving some form of support to subsidise the cost of production.

Today, the merits of burning biogas to produce electricity from any new-build AD plant are questionable, considering wind and solar can produce electricity much more cheaply. That said, these supply sources can be significantly more intermittent when compared to biogas.

It is widely accepted that the future of AD in Europe is to produce biomethane. Biomethane is purified biogas that can be used as a substitute for natural gas. It requires an extra step in an AD plant to remove CO2 and other undesirable gasses, typically through a membrane system, water or amine scrubber.

Biomethane will be targeted towards those sectors in transport and heat which are difficult or impossible to electrify, such as heavy-duty truck operations or commercial drying, pasteurisation etc.

There are 18 countries currently producing biomethane in Europe. As of June 2020, there were 725 AD plants in operation, producing around 26TWh of biomethane across Europe. This is an increase from 483 plants in 2018 and this has likely increased further over the past 12 months. Germany has the highest share of biomethane plants (232), followed by France (131) and the UK (80).

European ambitions

The AD industry across Europe has big ambitions. According to a report published by the European Biogas Association (EBA), biogas and biomethane production in Europe could double by 2030 and more than quadruple by 2050, with many of these plants farm-based.

France is leading the development of the biomethane market, with over 1,000 biomethane injection projects at different stages of development in the country. Europe has seen a rapid year-on-year increase in biomethane production capacity and so far, this growth shows no sign of slowing down.

There is a strong consensus that by 2030, biogas and biomethane production could reach 467 TWh across Europe. The implementation of the EU Green Deal will be a key determining factor in shaping the role of biogas and biomethane in future energy systems. A key growth area for biomethane is in the transport sector. The EBA projects that, of the overall production increase to 467TWh by 2030, around 117TWh will be available for the road transport sector.

This will allow for an increase in the share of biomethane used to fuel Europe’s natural-gas vehicle fleet, which it said will comprise of around 13.2m vehicles by the end of the decade. In comparison, only around 3.9TWh of biomethane was used to fuel natural-gas vehicles on European roads in 2020.

Compressed biogas (bio-CNG) has an advantage, in that much of the supply chain and infrastructure is in place. Most of the around 850 CNG filling stations in Germany have now switched to biomethane.

Feedstock

The EBA report states that there is a clear trend developing in terms of feedstock usage for biomethane production.

A move away from energy crops, towards agricultural residues, bio and municipal waste and sewage sludge began in 2013. From 2017, almost no new plants were established to run on energy crops, due to increasing sustainability criteria, the report says.