Thames: Desalination is currently unsustainable

Desalination is a “busted flush” unless there is a technological breakthrough, according to a director at the company that runs the only such plant in the UK.

Thames Water operates the country’s first and so far only desalination plant at Beckton in east London, which is capable of supplying sufficient daily water for around 400,000 households.

However, Richard Aylard, external affairs and sustainability director at Thames, told a break out session on the capital’s water resilience at the London Infrastructure Summit last week that desalination plants are expensive to run and inefficient in terms of carbon emissions.

“Unless there is a real breakthrough in terms of technology, it’s a busted flush. It’s just too expensive in carbon terms”, he said.

Thames’ existing plant is “technically very complicated to operate”, he added.

“If we were to run it at close to its full output, day in and day out, it would be ok but it would be massively expensive.

“If you keep it as drought option and wind it up and down, it’s very difficult to maintain and is expensive.

“The water you get from it is between 10 to 15 times as expensive as the water you can get from any other means,” he said, identifying getting leakage down, transfer schemes and storage as better ways of spending money.

“Desalination isn’t going to work unless there is a magic new technology.”

Aylard also said that Thames has slashed the sums it pays for sewer monitors from £1,000 to £50, which is helping the mass roll out of the devices for mapping leaks.

Introducing more monitors is enabling the company to gather data on water flows every quarter of an hour, he said: “By bulk buying and using the latest technology, we can get them for £50 which means we can map much more of the sewer network.

“Trying to map flows to work out exactly what is happening is pretty tricky, so we need a lot more monitors.”

Shirley Rodriguez, London deputy mayor for environment and energy, said that the Greater London Authority (GLA) had known desalination “wasn’t the right solution” when it opposed Thames’ application to build the Beckton plant more than a decade ago.

She said the GLA was seeking to improve London’s resilience to flooding by setting targets to increase the take up of SUDS (sustainable urban drainage schemes) in the capital’s emerging land use plan, which is currently being vetted by a government appointed inspector.

Rodriguez said the GLA is lobbying the government about securing extra powers in order to accelerate the roll out of SUDS schemes, which is currently reliant on partnership with regulators and companies.