INNOVATION November-December 2014

Opposite page top to bottom: The energy plant located in a neighbourhood park is one of three components of the district energy utility. The geo-exchange field under construction for the Alexandra District Energy Utility. Supply and return distribution lines and valves during construction of the Alexandra District Energy Utility. The Alexandra District Energy Utility earned the City of Richmond the 2014 APEGBC Sustainability Award. John Irving, P.Eng., Director of Engineering (r), accepted the award from Michael Bapty, P.Eng., FEC. This page: Distribution pumps in the energy centre circulate fluid throughout the system.

There are central pumps that circulate fluid throughout the system, says Milton Chan, P.Eng., Manager of Engineering Design & Construction for the City of Richmond. “A water-based fluid is pumped through the network. It picks up and transfers the heat from the boreholes to the energy plant in the park. From there the energy travels through high density polyethylene pipes below the street to the heat pumps in the connected buildings. The heat pumps elevate the temperatures for heating or reject heat back into the system for cooling. As the demand increases from a building, it sends a signal to our temperature sensor and the control valves in each building.” The system is continuously monitored by automated Direct Digital Control and the flow rate is closely watched and man- aged so that pump energy is not wasted, adds Postolka. “The level of usage of cooling has been much higher than anticipated, and that’s a good thing. All summer long they’ve been using the sys- tem and pumping heat into the field. Then during the winter, we extract that heat and put it back into their homes. The geother- mal’s back-up energy source is a 1.0 MW condensing, gas-fired boiler, but we haven’t had to use it yet.” The first phase of the Alexandra District Energy Utility now provides renewable energy to 850 residential, commercial and institutional units, says Irving. “At full build-out in 10 to 15 years, the utility will service up to 3,100 units while reducing up to 6,000 tonnes of GHG annually, the equivalent of taking 2,000 cars off the road each year.” The City committed $4.8 million to build the infrastructure for phase one of the ADEU. “We offered incentives to new buildings under construction in Alexandra and then passed a bylaw that any further developments in the neighbourhood would have to be built to connect to the ADEU system,” says Postolka. “At full build-out, ADEU will service approximately 3.2 million square feet of buildings at an estimated cost of $24.3 million in 2011 dollars. It is important to note that the ADEU was built without cost to the taxpayers. We’ve borrowed the money internally through the City’s Water Utility Reserve in order to build the infrastructure.” “We started off with the objective of making this system as simple as possible, just to get it off the ground,” says Irving. “We wanted to make sure everyone had certainty with what we were doing, so we established a fixed rate based on square footage. That way people wouldn’t have any uncertainty about what their district energy bill might be.”

The ADEU business model is based on two unwavering prin- ciples: the annual energy cost to consumers has to be equal to or less than the cost for the conventional energy for the same level of service, and the ADEU has to be financially self-sufficient with all costs to be fully recovered through user fees. “The geo-exchange technology itself is nothing new,” says Irving. “It’s been around for a couple of decades. In Richmond we have an older system that was installed in a community centre in the 1980s. The ADEU is unprecedented in scale, but we’re just upsizing the same principle. We had been looking to develop district energy for several years, but the best opportunity presented itself in the Alexandra District in 2010 when we reviewed a devel- opment application from Oris Geo Consulting. They had already implemented on-site geothermal in support of some smaller projects, and were now proposing to do this for a development in Alexandra, but they were faced with some on-site constraints. “Oris came to us wanting to partner up whereby they could build a geothermal system on city land that would support the two housing developments they were planning. Dana Westermark, the owner of Oris. presented us with this opportu- nity and was really the lynchpin to creating the whole utility. We developed a partnership agreement that would have them under a design-build contract and they would make their buildings dis- trict energy-ready. Oris would build the first phase of the district energy utility in return for a share of long-term revenue from those buildings. On that basis, the city committed to servicing those buildings and the broader neighbourhood.” The complexities of the project required expertise from many players, as Irving explains, “Oris hired Stantec to assume responsi- bility for the mechanical and electrical design. During the process we would have regular meetings with all of the players at the table providing feedback. We had Hemmera supporting us on a lot of the preliminary designs and design reviews. Their key players moved to Associated Engineering and continued to support us. We have Corix Utilities under contract to operate ADEU. They’re an entity that has a lot of operational experience. Every time we looked at the feasibil- ity of a design feature we’d have them comment and advise.” GeoTility was the geo-exchange contractor on ADEU. “Their specialty is drilling the holes in the ground and installing the pipes,” says Postolka. “Barnett Dembek Architects designed the building that houses the infrastructure of the district energy utility. Other key participants on the project included structural designers

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