Processing Magazine

Vancouver utility center supplies heat from sewage

February 7, 2013

The city of Vancouver is looking into the future, armed with a solution that is both environmentally friendly and cost-saving. A district of the city is using innovative technology that takes heat from Vancouver's sewage and uses it to heat the neighborhood, spanning 250,000 square meters.

The False Creek Utility Center has a heat recovery system that is unique in North America, although similar systems have been introduced in Japan and Norway. At the center of the process there is a heat pump, quite like the one present in every home's fridge. This one is huge and consists of a number of tanks and pipes. First, the water from the sewage is taken through a filter to separate the waste and then it runs through a heat exchange system, where the custom-designed heat pump extracts the heat from the water. Next, the heat is upgraded and transferred to pipes that bring hot water into homes and office buildings in the neighborhood.

It is estimated that about 70 percent of the total heating energy in the district comes from the sewage heat recovery system, while the remaining proportion is delivered through natural gas boilers. Those are now used mostly as a back-up because during the coldest winter days demand for heat is high and the sewage heat recovery system cannot meet all of it.

RELATED: Robot turns human waste into electricity

The city authorities are clearly pleased with what the False Creek Utility Center is doing for Vancouver because there are plans to more than double the capacity of the system, so that it can provide heat to other parts of the city as well. The process reduces greenhouse gas emissions by around 70 percent and is a perfect means to achieve Vancouver's goal to make all buildings carbon neutral by 2020, the Huffington Post said.

According to Chris Baber, neighborhood utility manager for the False Creek Utility Center, customers acknowledge the fact that by living in that area and being connecting to this system, they have a significantly smaller greenhouse gas footprint than residents in other districts of the city with a similar lifestyle.

Of course, there are drawbacks as well. Because of historically low natural gas prices, the sewage waste heat system is currently more expensive than the conventional heating system. However, it benefits from price stability, unlike natural gas, which can experience sharp fluctuations in costs, meaning that customers can find it hard to predict the amount of money they will eventually be charged.

Although waste sewage is a good option for heat recovery, the process is viable with other sources too. Globally, the popularity of district heating systems is growing. Iceland has the largest concentration of these systems -- about 95 percent market penetration, thanks to its ample geothermal energy. Denmark also fares well, with roughly 60 percent of the population being supplied with heat from district heating schemes, mostly from biomass.