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North Vancouver utility taps raw sewage to heat homes

The new plant will provide the greenhouse gas reduction equivalent of taking about 2,700 cars off the road forever.

The City of North Vancouver’s municipally-owned district heating utility will soon be warming buildings with an unconventional source – raw sewage.

The federal and provincial governments announced this month grants for the Lonsdale Energy Corporation to build a $24-million plant that will capture the heat going down our drains and send it back to more than 7,000 homes, businesses and public facilities.

“It’s exciting because it’s the first major low-carbon energy project that we will be building,” said Karsten Veng, Lonsdale Energy Corporation’s CEO.

How does it work?

Even on the coldest days in the winter, the water running through the sewer pipes is about 20 to 25 C warmer than the ambient temperature. When the new plant, which will be built across from the city’s works yard on West Second Street, comes online in 2027, it will use industrial heat exchangers to capture that warmth from the sewer pipes and pump it back into LEC’s system.

Despite the images that “raw sewage” might conjure, it is mainly our appliances that are heating our wastewater, not our own BTUs.

“We take raw sewage that’s flowing from people’s homes, from doing dishes or washing machines. Today, that heat is just being dumped into Burrard Inlet,” Veng said. “Instead of heating the ocean, we will heat homes.”

By reducing LEC’s need for natural gas, it’s anticipated that the sewer heat recovery plant will save about 7,600 tonnes in carbon emissions per year – the equivalent of taking about 2,700 cars off the road forever – allowing LEC to meet its mandate of sourcing 40 per cent of its energy from low-carbon sources by 2027.

City of North Vancouver Coun. Jessica McIlroy, who represents council on LEC’s board of directors, said the new plant is a very positive step forward in climate action.

“Strangely enough as it sounds, sewer heat recovery might not sound so sexy, but it’s in itself an exciting way to use waste, and to be resilient, and to use a resource that is there and available to us,” she said, adding that the technology has been well-proven all over the world.

The feds are chipping in $4.78 million for the project, while the province is contributing $12.76 million.

The outside support from senior levels of government has been “beyond valuable” McIlroy said.

“The effort to not only expand the system, but to decarbonize is one that requires significant investment. It’s not a cheap process and it is going to require a lot of different financial sources,” she said.

The project comes soon after LEC marked its 20th anniversary and at a time when governments at all levels are trying to transition away from fossil fuels. In the City of North Vancouver, buildings are the second largest source of greenhouse gas emissions that are fuelling climate change, trailing only transportation.

What is district energy?

The concept of heating multiple buildings from a central location dates back to ancient Rome. New York City launched a steam-based system in the 1870s.

The City of North Vancouver got provincial approval to create its own heating utility in 2003. The rationale at the time was that it would create a stream of revenue for the municipality while making the city less reliant on electricity from the relatively dirty and inefficient gas-fired Burrard Generating Station during times of peak demand. BC Hydro decommissioned that plant in 2016, but LEC’s gas boilers continue to burn.

It is now mandatory for any new buildings of more than 1,000-square metres within LEC’s service area to connect to the system.

Today, the LEC has grown to provide heat to about 7,000 homes in 108 buildings in Lower and Central Lonsdale, Moodyville and the Harbourside neighbourhood, using heat cranked out of eight energy plants connected by 15 kilometres of hydronic pipes. The water heats those buildings and their hot water supplies and then flows back to the plants to be heated again.

Decarbonization

About a quarter of the City of North Vancouver’s residents rely on LEC for their heating, but the 2003 assumptions and technology it’s been built on haven’t aged so well.

The LEC has a mandate to be carbon neutral by 2050, Veng said, and they are actively working on the roadmap for how that can be achieved.

Natural gas still accounts for about 85 per cent of the energy used to run LEC. That equates to approximately 19,000 tonnes of carbon emissions per year. The remaining 15 per cent comes from low-carbon sources – mainly renewable natural gas – but also solar panels on the roof of the city library, a geothermal system at the North Vancouver School District office, and a heat recovery system built into the winter ice rink in The Shipyards.

LEC also runs a small electric cooling system that feeds into a few Lower Lonsdale buildings. In the summer months, the LEC recaptures enough waste heat from the cooling system that it keeps the rest of the network’s showers and dish water hot without using any gas at all.

Although Veng could not discuss any details, some technologies the LEC may adopt in the future include ocean-source heat pumps, all-electric boilers, geothermal plants, and capturing heat given off by large arrays of computer servers.

“That’s where it becomes exciting because we do have some very ambitious plans,” Veng said.

In 2021, a cryptocurrency company went public with a proposal to provide heat from new Bitcoin-mining computers, however, that plan never came to fruition, Veng said.

Is LEC the right way?

The LEC isn’t without its detractors, however.

In city council chambers, the utility has been criticized for its monopoly position in the market, its higher home heating prices for consumers, the amount of debt the city has had to finance for its development, its lack of regulatory oversight by the BC Utilities Commission, and the fact that it forces developers and consumers to purchase heating from a carbon-intensive source when zero-carbon options – heat pumps also capable of providing increasingly critical cooling services in the summer – are now readily available.

LEC still owes the city $26.6 million in capital loans used to get the system to where it is today, but the utility is on track to have the debt retired by 2037. Currently, it pays interest payments at 3.51 per cent. According to LEC’s 2023 annual report, the utility posted $157,000 in net revenue on top of paying $1.8 million to the city in capital and interest payments.

McIlroy, who also works as a policy analyst for the clean energy think tank Pembina Institute, acknowledged buildings can be designed and constructed to such high energy efficiency standards now that they might have no need for a utility like LEC. But she said there are many different routes to net-zero emissions.

“It’s not necessarily useful to be very prescriptive on how we get there. We’re working towards the same end goal,” she said. “We need to allow flexibility for people to reach the goals we’re trying to reach.”

There are other advantages that come with a district energy utility. With multiple plants, the system has redundancies built in, meaning virtually no downtime. And because of LEC’s existing use of renewable natural gas, solar and geothermal, it already has a lower carbon footprint than most buildings that aren’t connected to the system.

“If all of those buildings had had standalone systems, they would have been emitting more. The emissions levels would have been higher,” McIlroy said.

And as projects like the sewer heat recovery plant come online, the transition away from carbon will happen much more smoothly for LEC’s customers than it will for residents in other buildings.

“If we had those buildings constructed in a typical manner with natural gas boilers and other types of systems in them, we would be looking to retrofit all of those buildings, one by one,” McIlroy said. “We’re also working very hard to improve and decarbonize and retrofit the system, which is expensive, but not as expensive as it would be to retrofit those 105 buildings.”

Veng made the same point, and characterized LEC as entering a new era.

“We’ve been developing LEC over 20 years. It’s been a growth phase,” he said. “We have been waiting for renewable energy sources to mature, to be able to maintain both affordable rates but transition to renewable energy sources.”