Vancouver looks to ocean for geo-exchange

West Vancouver is looking to tap into the ocean's heat as part of a new geo-exchange pilot project.

The idea, currently being analyzed by engineers, is to embed a series of high-density plastic coils in rock being placed off the shore as part of the municipality's erosion control program. If all goes as planned, those pipes will eventually be hooked up to a geo-exchange system to provide heat and cooling to both municipal buildings and private highrises in West Vancouver.

An ocean geo-exchange system works similarly to the way ground geothermal systems work, said Steve Jenkins, manager of sustainability, environment and healthy communities for the district. Both use small differences in temperature between two surfaces to provide heating or cooling.
Ocean geo-exchange is even more efficient than ground geothermal, said Jenkins, because "the ocean is a very stable temperature."

Jenkins said ocean geothermal exchange technology is "well proven" and has been used in other places. Toronto uses a system in Lake Ontario to provide cooling in summer, while Burnaby has installed geothermal pipes in a pond in the middle of a golf course. Several private waterfront homes in West Vancouver are also using ocean geoexchange technology, he said, and have found it cuts down the use of natural gas by up to 80 per cent. Use of natural gas is a concern, said Jenkins, because its use creates much higher carbon emissions than hydroelectric power.

So far, a commercial-size ocean geo-exchange project hasn't been tried in British Columbia. "We would be the first," said Jenkins.

The municipality decided to look into the technology because it has already been placing recycled rock below the tide line to form artificial reefs along the shoreline. That project, being carried out in conjunction with Fisheries and Oceans Canada, is intended to provide erosion control and aquatic habitat.

Jenkins said adding the geothermal pipe now would mean relatively small additional costs.
Engineers are still examining what kind of load requirements an eventual system could meet and how much a system would cost. But it's possible that both new development projects and existing waterfront highrises could one day tap into the energy source, in addition to municipal buildings.
Municipal staff is also talking to Terasen Gas -- now known as FortisBC -- about possibly partnering in a commercial geo-exchange project.

Because the pipes will be placed in the ocean, it's likely only buildings within a certain distance of the water could be hooked into the system, said Jenkins -- but he added that could extend to several blocks from the shore.

The municipality is hoping the ocean geo-exchange system could also be hooked into the aquatic centre. There, an existing ground geothermal project has reduced natural gas consumption by 20 to 30 per cent, said Jenkins. But the system still isn't large enough to supply heat for the main pool.

The push for geo-exchange technology is being driven by both environmental and financial concerns, said Jenkins.

The municipality paid BC Hydro more than $1 million and spent more than $524,000 on natural gas in 2009.

A report on the feasibility of the project is expected by the end of March.

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