In this part of Vancouver, innovative technology is harnessing heat from wastewater and using it as a renewable energy source to heat homes.
When the occasional snowfall dusts the streets of Vancouver in the midst of winter, the layer of white can quickly become punctuated by steaming openings where it has already melted. The access holes to the drains below ground are caused by the heat flowing through the city's sewers, warming up the pavements.
"There's enough heat in the sewerage system to literally heat up neighbourhoods," remarks Derek Pope, manager of neighbourhood energy for the city of Vancouver, Canada. "That's what we've been doing here in False Creek since 2010."
The residents of False Creek, a recently redeveloped neighbourhood of Vancouver, on the west coast of Canada, get their energy from a rather unusual renewable source – their sewage wastewater. Increasingly, municipalities around the globe are harnessing this underground form of excess heat as they decarbonise their energy networks.
Residents in the 6,210 apartments in the False Creek neighbourhood get their heat from renewable energy sources, with sewage heat being the largest contributor.
Everything that goes down our drains ends up as sewage water – from what we flush down the toilet, to what comes out of our baths and washing machines. Down the pipe it flows, eventually ending up in a wastewater treatment plant where it is chemically, biologically and mechanically cleaned and treated, ready to be recirculated back into our homes once again. But the heat that's generated from the dishwasher or a long, hot shower is generally forgotten about once it washes down the plughole, explains Pope. Instead it heads underground, and straight into the sewer systems – escaping out of vents and melting through winter snow.
Heat in water is relatively easy to harness once it's in the sewage system because it's contained – and no, any heat recovered isn't going to smell. By comparison, heat in the air quickly escapes out of windows, doors, and roofs. In addition, there's plenty of hot wastewater to work with. In 2020, experts at the London South Bank University estimated that energy from the UK's daily 16 billion litres of sewage wastewater could, in theory, provide more than 20TWh of heat energy annually – enough to provide space heating and hot water to 1.6 million homes. Over in the US, Americans flush an estimated 350TWh of energy down the drain each year – the equivalent of heating 30 million homes a year.
The biggest challenge is a lack of integrated, forward-thinking urban planning, argues Pope: "We need to start viewing waste heat as a resource and find ways to incorporate that into our city planning." While he acknowledges there's some upfront capital cost, Pope explains the neighbourhood energy unit in False Creek is set to recover its outgoings; residents pay utility rates and the cost of low-carbon energy is relatively low, plus the recent expansion has been part-funded by a grant that supports projects reducing greenhouse gas emissions. Next, he wants to see more municipal governments make that step to implementation.
