Anaerobic digestion offers farmers great potential for converting waste to biogas than can be converted to electricity, but its proliferation in the UK is being held up by that country’s planning process, according to RenewableEnergyWorld.com.
AD plants are now up and running in many parts of the country; it is being backed by the UK’s coalition government; and, according to the web site, there is great untapped potential for wider use of the technology. Yet the UK lags behind the rest of Europe when it comes to AD technology.
In Germany there are around 6,000 operational AD plants. RenewableEnergyWorld.com attributes this to government support in the form of feed-in tariffs higher than their UK equivalent, greater initial funding, and greater efforts than in the UK to overcome hurdles such as gas line connection. Denmark’s national energy policy includes a section on biogas and a specific policy that provides 30 percent on initial establishment costs.
But the main reason for slow uptake in the UK is planning policies, according to RenewableEnergyWorld.com. Before the Localism Act came into force in 2011, planning policies gave specific advice on what to include in a planning application for an AD development. But this guidance was “swept away” by the Localism Act and by the National Planning Policy Framework. The current NPPF makes no specific reference to biogas or AD, refering only to the blanket term “renewable energy.”
Anecdotal evidence suggests that many local planning departments have little or no experience dealing with an AD planning application and., as such, are likely to reject initial applications.
According to research carried out on local authority planning departments by by RenewableEnergyWorld.com, relevant policies tend to focus on “large-scale residential or commercial developments and associated renewable energy obligations.”
To help secure successful and timely planning applications the web site recommends hiring a consultant with a combination of expertise on planning and AD technology.
In March, Thames Water announced plans to spend £250 million ($37.7 million) on thermal hydrolysis process plants to enhance its “vast poo power” program, which converts sewage sludge to electricity.
The UK water company saved about £15 million ($22.6 million) last year on its power bills by generating 14 percent of its annual energy requirement from sewage.
THP plants — essentially industrial-scale pressure cookers — condition the leftover solids from wastewater treatment by heating it up to around 160 degrees Celsius.
The pre-conditioned sludge then goes into existing anaerobic digesters that break it down, producing biomethane gas that is then burned to create heat and generate renewable electricity.