Natural Resources, Mining, Industry and Energy Tree for Life Award and Award of Excellence
Blatchford District Energy System Phase 1 Associated Engineering
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A broad mandate AE supported design, construction and operation planning for Blatchford’s energy system. The firm provided ownership and operations delineation, builder design guidelines, maintenance and operations guides, infrastructure and controls design, stakeholder engagement, regulatory review, end-user pricing analysis (i.e. rate setting) and GHG reductions analysis. Review and feedback bodies included the city’s finance department, city council, public and private stakeholder committees and third-party technical reviewers. This joint approach helped ensure the cityowned and -operated community would serve a broad mandate, addressing climate change while balancing technical, financial and social needs. 20
CANADIAN CONSULTING ENGINEER
Modular growth Edmonton’s vision for Blatchford is to accommodate up to 30,000 people in a sustainable community that uses 100% renewable energy, is carbon-neutral, significantly reduces its ecological footprint and empowers more sustainable lifestyle choices. As the largest application of an ambient-temperature energy distribution system in Canada, the design features: interconnected nodes of centralized heat pumps, which distribute ambient temperature water to heat pumps in each building; the integration of renewable and low-GHG energy sources, such as geoexchange (i.e. transferring heat from and to the ground), sewer heat exchange, auxiliary boilers, cooling towers and a solar photovoltaic (PV) array; and the sharing of energy between those buildings rejecting heat and those requiring it. The system is also modular, as the neighbourhood is being built out in stages over 25 years. The heat pump nodes allow flex-
ibility for connected additional energy sources over time. The first phase Phase 1 involves a nearly 3-km long ambient-temperature (approximately 10 C) high-density polyethylene (HDPE) distribution pipe system (DPS), featuring supply/ return fusion-welded piping up to 600 mm in diameter. The DPS is largely collocated with other major utilities. Most of the renewable energy for heating and cooling in the first phase comes from a ground-coupled heat exchanger (GHX). Geoexchange test drilling and conductivity testing were completed to develop a site-specific 570-borehole field design. The holes were drilled 150 m beneath a naturalized stormwater retention pond. As the neighbourhood continues to grow, the number of boreholes will increase to 2,100. Subsequent phases will also use heat from sewer water that otherwise would be wasted. September/October 2022
PHOTO COU RT E SY A S S O C I AT E D E NG I N E E R I NG
fter the 2013 closure of Edmonton’s city centre airport, the municipal government sought to develop an environmentally friendly community in the area. Associated Engineering (AE) collaborated with the city to design the Blatchford neighbourhood’s district energy sharing system. Powered by renewable energy for heating, cooling and hot water, it will be the largest system of its kind in Canada, with homes using heat pumps to share unused energy, thus reducing greenhouse gas (GHG) emissions. Blatchford’s energy strategy was developed around three key pillars that increase resiliency while minimizing emissions: conservation, efficiency and renewables. Sustainable by design, the project looks set to serve as a model for the future.
