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Case StudyHybrid heating a winning solution forWinnipeg’s MTS CentreBy Malcolm Metcalfe, P.Eng.While the idea of retrofitting the heating system of a threeyear-oldbuilding may seem odd to most, Winnipeg’s MTSCentre has proved that, sometimes, counter-intuitive makessense.Opened on November 16, 2004, the 17,000-seat hockey arenaand entertainment venue is located in the city’s downtown, linkingthe Portage Place and Cityplace shopping complexes via a walkwaythat’s always open to the general public. The centre cost $133million to build and boasted many state-of-the-art features whenit opened, including a modern natural gas heating system to coverthe 440,000 sf of space spread out over several levels.But the building’s owners, True North Sports and Entertainment,knew they could do more to curb GHG (greenhousehas) emissions and save on energy costs. An energy audit byBC-based Sempa Power Systems Ltd. confirmed the MTS Centrewould benefit by taking advantage of the electricity market inManitoba through the use of Sempa’s Hybrid Heating System.The potential of hybrid heatingHybrid heating applies the idea behind hybrid vehicles to commercialbuilding heating systems, providing the ability to switchintelligently between natural gas and inexpensive off-peak electricityto reduce GHG emissions and cut energy costs. Afterretrofitting the MTS Centre in 2007, True North Sports andEntertainment realized a reduction in GHG emissions by morethan 60% each year.Equally significant, the retrofit has helped thefacility save nearly $85,000 annually (about 12%)off the cost of heating with natural gas alone. At apre-tax cost of less than $300,000, the retrofit willhave paid for itself in less than four years.Manitoba’s electricity marketAlmost all of Manitoba’s electricity comes fromrenewable hydro resources, qualifying it as ‘green’.Equally significant, Manitoba Hydro offers electricityat a price that is significantly less than fossilfuel during off-peak demand periods.That’s one piece of the puzzle; another is theenergy-equivalents calculation, which simplifies costcomparisons between different fuels. For example,the price of electricity is usually expressed in kW/hand natural gas in cubic metres (m 3 ), which is likecomparing apples to oranges. So, to compare applesto apples, it is more accurate to express fuel costs ingigajoules (GJ) of delivered heat. The MTS Centrecost for natural gas is about $16/GJ compared to lessthan $7/GJ for off-peak electricity.The ideal solutionDespite the benefits of off-peak electricity, True NorthSports and Entertainment wasn’t about to mothballits brand-new natural gas system, and the cost of electricityduring times of peak demand is high, makingit impractical as the sole source of heat.That’s where the hybrid heating system enters thepicture. At the heart of the system is a set of intelligentcomputerized controls that switch between natural gasand electricity (any two fuels can be used) dependingon current electricity demand in the building andestablished monthly peak demand.When the electricity demand is below theestablished peak demand for the month, the systemwill switch from using natural gas to electric heat;conversely, when demand in the building increases tonear peak load, the system switches back to naturalgas. This way, all electric heat is purchased withoutany additional demand charge.The MTS Centre project required the installation of:• a single 500kW electric hot water boiler(plus controls) to serve the primary heating loopsand the domestic hot water systems;• a single 150kW electric heating coil on themake-up air unit (plus controls); and• a Sempa-designed hybrid heating controlsystem to enable management of the twoheating systems.Installation was carried out transparently, with nodisruption to operations. At $290,000 (before taxand including all parts and labour), the total cost ofthe project was less than three-tenths of 1% of thecentre’s original construction cost. And the savingsbegan to appear on the ledger almost immediately.Annual savings work out to just under $85,000 andaverage about $10,000 for each of the five coldestmonths (November to March, inclusive).And by replacing sizable portions of its fossil-fuelconsumption with clean and renewable hydroelectricity,the Centre reduced its GHG emissions bymore than 60% annually.John Olfert, CEO of True North Sports and Entertainment,observed that “since MTS Centre openedin 2004, we’ve continued to look for ways to improveenvironmentally and save on our energy costs. [This]allows us to do both: reduce our emissions dramaticallyand provide a very attractive return on ourinvestment”.Malcolm Metcalfe is the chief technology officer of SempaPower Systems Ltd., the maker of the Sempa Hybrid HeatingSystem. He earned a B.Sc. in electrical engineering andan M.A.Sc. in power systems from the University of BritishColumbia. Before establishing Sempa, he worked at BC Hydroand Shell Canada. You can contact him at mmetcalfe@sempapower.com.Cooper_EB_Nov08.indd 124 • november/december 2008 • www. mag.com11/24/08 12:34:40 PM