About Anaerobic Digestion
Anaerobic digestion (AD) is the process that transforms organic waste into renewable gas.
Anaerobic digestion: The future of sustainable energy
Anaerobic digestion (AD) is one of the most promising technologies in the renewable energy sector, and at ENGIE we’re proud to be a leader in its UK development and implementation. AD is a biological process that breaks down organic materials, such as agricultural waste, food waste, and sewage, to produce biogas. This biogas is cleaned and can then be injected into the national gas transmission system or converted into electricity and heat, creating a sustainable and efficient energy source.
Outputs of the AD process
Achieving net zero
At ENGIE, we are committed to achieving net zero emissions through the expansion of anaerobic digestion technology.
By scaling up biomethane and AD projects and improving their efficiency, we help reduce carbon emissions while generating green energy. AD not only contributes to the fight against climate change but also supports industries in their efforts to meet sustainability goals and reduce their carbon emissions.
Debunking myths about anaerobic digestion
Anaerobic digestion is great for businesses of all sizes that produce organic waste. It may seem like it’s more popular with big companies, but that’s only because they tend to shout about their green practices more!
Over half of the feedstock providers we work with are small local businesses and farmers. Anaerobic digestion is not just a rich person’s play thing, it’s a real way to sustainably create value out of waste. For many farmers, AD is especially useful as our digestate bi-product makes great fertilizer and the biogas helps fuel their farms.
Anaerobic digestion actually increases the demand for jobs. While machinery does the bulk of the digesting work, the whole operation requires a hardworking, meticulous team to check the machines are running as they should be. On top of this, AD boosts a range of other jobs, such as managing feedstock production, fertiliser, and maintenance.
Some people are concerned that using crops as a feedstock for producing green energy is a waste, when these crops could become food instead. Arable land is already being used for purposes other than food production, though – more cereals are grown for brewing and distilling than for energy crops!
It’s not possible or sustainable to continuously grow food crops, as the soil will gradually lose its nutrients. AD feedstock crops are grown as part of a crop rotation cycle with natural digestate fertiliser, helping to replenish organic matter and improve the soil. This means farmers can grow better quality food in the next cycle.
Some of the feedstocks that fuel a digester can produce a bit of a stink (such as manure and chicken litter), but these smells aren’t permanent. Plants want to turn their feedstock into green gas as quickly and efficiently as possible, so the feedstock isn’t around for long. This also means that the smell rarely spreads beyond the plant. In fact, one of our AD plants is situated directly next to a wedding venue and we haven’t had any complaints!
This is the most common misconception about AD. AD plants are often situated on agricultural land, as this is the most beneficial location for our feedstock providers who tend to be farmers and small, rural businesses. This helps cut travel costs and allows farmers to make profit from their waste.
Prior to AD plants, farmers had to remove their waste, (often via large lorries or tractors), to a landfill or similar facility that could be miles away. Instead, AD diverts the waste to a different place, which is usually just a short trip down the road.
Prior to AD plants, farmers spread their agricultural wastes and residues, such as farmyard manure and cow slurry, straight onto their land. Therefore these feedstocks were already being transported, but they are now being directed to a local AD plant, rather than being spread on fields.
We aren’t too sure where this myth came from, as all the AD sites we’ve seen are safe – and very clean!
Having clean, tidy and safe working conditions for our team means we are able to operate even more efficiently.