by Megan Darby
Northumbrian Water plans to boost production of biogas and inject it into the grid, chief executive Heidi Mottram told Utility Week in an exclusive interview (see page 16).
Northumbrian imminently expects to be using 100 per cent of its sewage sludge to generate power, using advanced anaerobic digestion (AD) to create biogas. Next, it plans to introduce food waste into the digestion mix, an enterprise currently hampered by diverging sets of regulation.
“There is no regulator fighting us, it’s just working through the bureaucracy,” said Mottram. Meanwhile, the company will satisfy the regulations by putting food waste into the system earlier than necessary, so it can be classified as sewage sludge. “It could go in further down the process but it is not a big deal. We can crack on with getting more gas,” she said.
Rather than burn the resulting biogas to generate electricity on site, as at present, the company is working with Northern Gas Networks on injecting it into the grid.
The only UK sewage gas-to-grid project tried to date, at Thames Water’s Didcot works, has been beset with technical problems since its launch in October 2010.
A Thames Water spokesperson said: “We have had issues with the amount of gas coming from our digesters, but are currently working on plans to improve their performance and hope to be up and running in the next few months.”
Mottram was confident Northumbrian’s scheme, involving around ten times the volume of gas, would work.
This article first appeared in Utility Week’s print edition of 31 August 2012.
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