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Wednesday August 2 2023

The future of biogas – is it the answer to the energy crisis?

The ongoing war in Ukraine has sparked a continent-wide energy crisis that has cast the spotlight on our dependence on imported gas – particularly from Russia – and the need for greater security in energy supply.

The crisis has been the driving force behind a major cost of living crisis and, crucially, many fear it is also threatening the future of the planet by dampening bold ambitions to address climate change as Governments’ battle to find a solution to the situation, regardless of the environmental impact.

The recent political turmoil in the UK also heaped further misery on the energy sector as they look for certainty to invest in alternative sources.

However, this crisis is once again throwing the spotlight on renewable energy sources and the potential for renewable biogas solutions.

Anaerobic digestion energy production

In the UK, leading anaerobic digestion organisation, the Anaerobic Digestion and Biogas Association (ADBA) have already written an open letter to the Government saying biogas could provide a quick, short-term solution to the national energy crisis.

Chairman of ADBA and former Energy Secretary, Chris Huhne, claims the Government could provide national energy security and help cut consumer bills by rapidly deploying new anaerobic digestion plants across the UK.

In calling for red tape to be cut, Huhne says a major network of anaerobic digestion plants could be built in just two years and he adds that this roll-out could help cut UK greenhouse gas emissions by 6%.

In lamenting, the omission of biogas and biomethane from the Government’s current energy strategy, he also said: “Biogas derived from organic wastes can provide a substantial alternative to gas imports while also generating revenue for the Treasury that could be used to alleviate consumer bills.”

The future of biogas

This sentiment is being echoed across the EU, where many of the members are even more dependent on Russian gas imports.

EU lawmakers have already committed to double biomethane production as they battle to secure energy supplies and the momentum for anaerobic digestion technology is growing.

Germany, in particular, is heavily investing in biogas because of its reliance on Russian gas imports.

Denmark is arguably the world leader in biogas, with around 55% of their gas supply coming from biomethane. This is largely due to the fact they have a huge number of pigs across the country and have a good supply of feedstock from slurry for anaerobic digesters.

Not only does this movement toward biogas help provide energy security, it also tackles climate change by harnessing the harmful gases released from organic waste and turning them into energy.

Constructing new biogas plants

As part of their letter to Government, ADBA are making a series of demands to help accelerate the construction of anaerobic digestion plants.

The Government already has a new Green Gas Scheme that aims to support the development of new plants, but this new scheme does present challenges, chief among which is the criteria that 50% of the feedstock used must be waste.

The Green Gas Scheme runs for 15 years and is still a good investment, but it does lend itself towards bigger plants. To meet the criteria for the scheme though, AD plant operators will need to have security of supply for waste.

As a result, ADBA is calling for the Government to accelerate the implementation of mandatory separate collections of food waste across the UK, to support the rapid deployment of biogas and biomethane infrastructure (in a similar way to the support seen for the wind and solar sectors), and to cut red tape for biogas producers, including the “onerous” planning procedures.

Anaerobic digestion of food waste

As it stands, the Government is planning to ban food waste from landfill from 2024. In theory, this is great news for a strategy to scale up the network of anaerobic digestion plants in the UK as it could potentially provide security of supply for the feedstock.

However, this is not without issues. Firstly, the councils have to find ways to manage the food waste and the costs associated with that. Previously, councils had to pay to dispose of food waste, but this new strategy will inevitably see them selling food waste to anaerobic digester operators. Plus, with the new Green Gas scheme, we could see a lot more competition for food waste.

For the anaerobic digestion operators, many have previously relied on energy crops to feed the plant as this offers a guaranteed supply and has a predictable calorific value, making it much easier to manage the complex biological reactions.

The digestate produced from the anaerobic reaction is also of a high quality and can simply then be spread back on the land to help cut the need for costly fertilisers.

With food waste, this presents a range of issues. Firstly, it is going to be extremely challenging to remove plastic from food waste and the resulting microplastics in the digestate means that we won’t then be able to spread it on the fields.

Secondly, the varied mix of food waste will make it extremely difficult to predict the calorific value and that will make it hard to predict what the output will be and how best to manage the biological reactions inside the digester.

Other things like chicken bones will be classed as food waste and included, but these will have zero value in terms of generating biogas and will simply fill the digester, meaning operators will have to have them emptied more often.

We are starting to see the emergence of companies that will process the food waste, removing plastic etc, and then create a “soup” that can be fed straight into AD plants, but all of this again will add extra costs to the system.

Advantages of biogas

Biogas can play a critical role in tackling the energy crisis, but it will have to form part of a wider mix to provide security and help to tackle key climate issues.

Currently, biogas upgraded to biomethane, only makes up about 2% of the UK’s gas supply and that is being generated by just 150 plants, so there is huge potential to scale the network up.

Biogas can also provide a constant source of energy, unlike wind and solar which generate power intermittently depending on the weather conditions.

It is arguably the only energy solution offering a true circular economy as it tackles organic waste, produces biogas or biomethane for the national grid or for fuel and then leaves behind a digestate which is a perfect natural fertiliser for food crops.

We also have the infrastructure needed with the existing gas network. You can simply inject the green gas straight into the network without any modifications to pipeline infrastructure or commercial/domestic gas appliances.

The current situation and ongoing energy crisis is a perfect opportunity for the biogas industry and, while we don’t know how long the high energy prices will last, anaerobic digestion plants will continue to be a solid investment as we look to tackle waste and provide energy security in the future.

If you’d like to know more about how biogas can be used as part of your energy mix, speak to our expert team at enquiries@birchsolutions.co.uk