Future of AD is small to medium-scale predicts energy expert

The anaerobic digestion (AD) industry is on a steady march, but the future growth in the sector is more likely to be through small-to-medium scale plants than large-scale projects.

Speaking at the Institution of Chemical Engineers’ seminar on delivering low carbon energy from biomass resources in London yesterday (2 May), director of EHV Engineering Prab Mistry said that the future of large-scale AD projects could not be guaranteed.

“I fear that their life is as long as the incentive that the Government is currently offering,” he warned.

Mistry explained that large-scale plants were viable at the moment because they could attract up to 25-30% returns on investments. However, behind the headlines, a shift towards small-to-medium scale AD projects that generated 500-2,000 kilowatts of biogas was taking place.

“There is a convergence towards no feedstock costs and that leads me to believe that the future is actually medium-scale,” he told delegates.

Mistry said that there had been a sudden rise in AD plants in the UK from around five plants back in 2004 to around 90, most of which had been built in the last two to three years.

“There will be more large-scale AD plants based on food waste but they will not survive beyond the subsidy in my opinion,” he concluded.

“But small and medium-scale plants will have a greater future, especially when they are integrated with food supply chains.”

Energy from biomass covers a range of sources, including domestic food waste. Currently, bioenergy accounts for around 3% of the UK’s total primary energy production but is set to increase.

The one-day event provided delegates with an insight into the latest technologies, suppliers and markets that are driving the implementation of biomass technologies towards 2020.

Nick Warburton

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