According to the Exeter Centre for Circular Economy, ‘the transition to a circular economy is not a matter of choice. It is a necessity’. Anaerobic digestion (AD) has a vital role to play in the creation of a circular economy, generating renewable energy from waste while working in harmony with local agriculture and communities.

What is a circular economy?

In a circular economy, waste products are regenerated as part of a sustainable system that operates within the limits of our planetary resources. This system works in opposition to the more common linear economy, which extracts resources, uses them, and then throws them away – known as the ‘take-make-waste’ model.

AD is a perfect example of the circular economy; at the core of the process are numerous cycles, whether biological, agricultural, or financial. The key steps in these cycles are outlined below.

Step 1: Converting farm and food production waste

Our AD plants are supplied by organic feedstocks, which are broken down to generate biogas. For example, local farmers supply us with animal manure, agricultural waste, and sustainably grown crops.

Did you know that food waste is the third largest contributor to greenhouse gas emissions? We work with local food production companies to convert their waste by-products into energy, such as:

  • Apple pulp leftover after cider making
  • Whey from dairy production
  • Rejected potatoes from supermarket bagging plants

Therefore, AD can offer an environmentally friendly disposal solution for both farmers and food companies.

Step 2: Powering local homes and businesses

The biogas generated by feedstock breakdown will be processed, upgraded, and injected directly into the UK’s gas network. It can also be used to generate electricity, which is exported to the National Grid.

Green gas and electricity produced by our AD plants will directly supply homes and businesses in the surrounding area. Each year, we generate enough renewable gas to power 9,751 homes and renewable electricity for 9,910 homes. Since this energy is locally produced, it avoids the volatility of international energy prices caused by events such as Russia’s invasion of Ukraine.

Step 3: Helping to grow quality food

Digestate is an organic by-product of AD that is high in nutrient content, making it a great natural fertiliser. It can replace artificial fertilisers derived from fossil fuels, which helps farmers to reduce their carbon footprint and mitigates the dramatic price rises of artificial fertilisers.

Not only is digestate used on feedstock crops for AD, but it also fertilises food crops that may not otherwise have been affordable to grow. Households then buy food from the farmers and food companies who initially supplied our AD plants with feedstock. This completes the cycle of the circular economy.

Other contributions to the circular economy

Outside of these core processes, there are several further ways in which AD contributes to the circular economy model. For example, AD supports the rural economy by paying farmers a fair and consistent price for the feedstock they supply, allowing them to diversify their income.

“The last five or six years have been very challenging for the beef and sheep farming sector. AD has provided a great opportunity for farmers to diversify their businesses. We can certainly see the benefit that Condate Biogas has brought to agricultural businesses in the area, ourselves included.” – James and John Govier, Great Hele Farm

Jobs in the renewable energy sector are currently growing at a rate four times faster than the rest of the UK job market. As well as creating job opportunities, AD plants also boost community success through education and driving innovation.