London is building a power plant that burns waste fat from sewers
Before you read this, please finish your breakfast.
In 2015, East London will be home to a new type of power plant that uses a unique renewable energy source -- discarded fat. Yes, fat. Everyday, fat, oil and grease (FOG is the acronym being used) build up in the city's sewer system, causing blockages or "fatbergs."
City workers must remove the build-up to keep the system running smoothly, but now the fat will be used to power the Beckton sewage works, a nearby desalination plant and even be fed to the grid. The plant will contribute enough electricity to power 39,000 homes.
According to Thames Water, fat causes 80,000 blockages a year, mainly from grease and oil that has been poured down the drain. When this new power plant is built, Thames Water will deliver 30 tonnes of FOG every day for burning, which will cover more than half of the power plant's fuel needs. The rest will be collected from traps which will intercept fat from city kitchens before it goes down the drain and from other waste animal and vegetable oil sources. Virgin fat will never be used in the power station.
Thames Water explains the technology behind the plant, being built by company 20C:
2OC's Combined Heat and intelligent Power (CHiP) station will be built around a two-stroke marine diesel engine, the kind which normally power large ocean-going vessels. This engine will be roughly the size of a large detached house. Waste heat from the Beckton CHiP generator will be used to heat up gas as part of the pressure reduction process at the adjacent Beckton gasworks. The gas pressure has to be dropped to make safe for delivery to homes and businesses. Lowering the pressure of a gas causes a huge drop in temperature, which could freeze and crack pipework. Using waste heat from the engine will reduce the need from gas to be burned to produce the heat currently required to do this job. 20C will also recover some of this thermal energy to generate even more electricity.
"This project is a win-win: renewable power, hedged from the price fluctuations of the non-renewable mainstream power markets, and helping tackle the ongoing operational problem of 'fatbergs' in sewers," Thames Water's commercial director Piers Clark said.
And in case you were wondering about how smelly this power plant might be, Andrew Mercer, the boss of 20C, told the BBC "we turn it into a fuel and run it like you would run your car" and claimed there would be "no smoke (and) no smell."