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UK - tough times ahead for small scale biogas power generation?

Tuesday, 27 July 2021

Recent figures released by the National Non-Food Crops Centre (NNFCC) showed promising growth for the UK Anaerobic Digestion (AD) sector despite a challenging year. However, power generation from biogas has come under heavy competition from other renewables technologies.

The NNFCC figures suggested that the AD sector grew by 11% over the past 12 months since April 2020, bringing the total number of operation plants to 642 . Almost 70% of these digesters were fed with feedstock from farming activities, including manure and crops. The remainder were waste-fed. Food waste as a feedstock saw impressive growth, by more than 20% to be the largest source of feedstock at just under 5 megatonne for the year. On the other hand, crop feedstock usage dropped marginally by 3% to approximately 4.2 megatonne.

Most plants built had applied for government support via Feed-in Tariffs (FiTs) where the biogas is slated for electricity generation, or the Non-Domestic Renewable Heat Incentive scheme, which offers payments for biomethane (upgraded biogas) injected into the national grid.

Support schemes were closing to new applicants in 2021, so there had been a rush to commission plants. However, Covid-19 and inclement weather held up many construction plans. Fortunately, the government stepped in and offered a 12-month grace period for FiT projects to account for these hardships, in addition to a commissioning deadline extension for NDRHI projects which had secured funding.

However, the number of projects under development has dropped by approximately 20% compared to last year (331 to 269). Many of these AD projects (75%) are associated with electricity generation via Combined Heat and Power (CHP) plants.

By the numbers

A representative from the NNFCC suggested that these CHP related projects are likely to dwindle further, due to renewable energy from other sources (wind and solar in particular) offering competitive pricing per kWh compared to biogas CHP generation. This is expected to impact the small to medium-scale AD projects in particular.

However, the introduction of the UK Green Gas Support Scheme (GGSS - part of a BEIS proposal, presumed to have been given the go ahead for an August start this year) should still offer ample support for AD projects aiming to upgrade their biomethane and injected into the grid.

The NNFCC suggests that these changes will see the balance tip towards larger AD for biomethane plants in comparison to CHP applications heading towards 2022 and beyond. This is likely to be at the expense of small farms, who often produce biogas from their produce and waste for CHP plants. However, farms were highlighted for their feedstock potential, even if it becomes uneconomical to produce biogas on site. Smaller farms can become integral to the biogas/biomethane supply chain, delivering their feedstock to larger AD plants with economies of scale.

A National Farmer's Union (NFU) representative suggested that the wider benefits of AD have been overlooked by policymakers while designing these policies. According to him AD has the potential to help smaller producers including farms as manure and slurry waste are still vastly underutilised, and as is the digestate by-product is an effective fertiliser.


Farmer's Weekly