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Xcel EnergyAN INNOVAS TECHNOLOGIES CASESTUDY1

Xcel EnergyAN INNOVASCASE STUDY TECHNOLOGIES CASE TECHNOLOGIESAN INNOVASSTUDYMike O’Malley, embracing Xcel Energy’scommitment to sustainability excellence, found agreat opportunity to significantly improve chillerefficiency in the district cooling plant he managesin Denver, Colorado.CASE STUDY HIGHLIGHTSElectricity Cost Savings:Energy Conserved:GHG Emission Reduction:Equivalent Cars Removed:Equivalent Trees Planted: 62,000765,000 kW-hrs582 tons10313,0002

INTRODUCTIONImproving the efficiency & productivityof central cooling plants.Xcel Energy is one of thelargest combined electric andnatural gas utilities in thecountry and is a recognizedindustry leader in deliveringrenewable energy andreducing carbon and otheremissions, efforts that put thecompany on a path to a moresustainable energy future.Specifically, Xcel Energyprovides power generation anddistrict cooling services in 8states in the western, southernand midwestern US.Capable of generating over17,000 MWs of power, XcelEnergy serves over 3.3 millionelectricity customers and over1.4 million natural gascustomers throughout itsservice area. Also, Xcel Energyprovides district cooling inColorado.Xcel Energy Case Study – Innovas TechnologiesXcel Energy is a highlyinnovative company asdemonstrated by itsannouncement in 2018 that itaspires to deliver 100% carbonfree electricity to customers by2050 - the first major US utilitycompany to set such anambitious goal.Mike O’Malley, embracing XcelEnergy’s commitment tosustainability excellence, foundan opportunity to significantlyimprove chiller efficiency in thedistrict cooling plant hemanages in Denver, Colorado.Mike’s knowledge of thenegative effects of condensertube fouling and his search fora method to improve chillerefficiency led him to InnovasTechnologies for the solution.3

THE CHALLENGEAs is so often the case,adopting innovativetechnology requires a highdegree of evaluation andconsideration regarding a newapproach’s impact.In Xcel Energy’s case, Mr.O’Malley knew there was roomto improve chiller efficiencythrough tube foulingmanagement. Subsequently,Mike served as the thoughtleader for integrating theHelios Tube Cleaning System onto a single 2,500-ton chillerfor a seasonal evaluation.The plant has excellent dataacquisition systems and inMike’s opinion, it would be easyto determine the impact of theHelios installation over thecourse of a complete coolingseason.In Xcel Energy’s case, thebiggest challenge was freeingcapital funds to purchase aHelios TCS on a short notice.Mike O’Malley was successfulin finding a fundingXcel Energy Case Study – Innovas Technologiesopportunity and was able toprogram in the new system.Once funded, the evaluationwas enacted. Mike understoodthe large potential savings andwas the key leader in gettingthe program started.THE SOLUTIONInstalled on a 2,500-ton chillerin the downtown DenverCentral Cooling Plant, theHelios Tube Cleaning System was run throughout thenormal cooling season in 2018.Chiller operation andperformance data wasrecorded from the same chillerfrom 2017 before it wasequipped with the Helios.As the data demonstrate, theHelios Tube Cleaning System significantly improved chillerefficiency and increased chillercooling output during the 2018cooling season.THE LESSONThe lesson continues to be4

reinforced at Helios TubeCleaning System installationsthroughout the country.As previously stated, when thetubes on either side of a chillerremain clean and free offouling, the chiller efficiencyimproves, and operating costsreduce. This is a generally wellknown fact, but it is sometimeshard to quantify.In Xcel Energy’s case thesavings are solidified by thedata and equate to a solidpayback. Most organizationsask the same question, “Webelieve the data at the otherfacilities, but how much willthe system save us at ourorganization?” The answer canusually be found by analyzingthe historical chiller operationsdata.Assuming the data is suppliedby reliable/calibrated sensors,the approximate cost offouling-related inefficiency canbe identified.Once the data is analyzed aconsistent truth is exposed.Xcel Energy Case Study – Innovas TechnologiesNo facility using water-cooledchillers is immune fromfouling-related loss. None. Untilnow.While typical chiller tubefouling losses will vary fromplace to place based on thequality of the water source,local air quality, and watertreatment programs, thegrowing data collection fromchillers operating with Heliossystems confidently suggests asavings of 6% to 10% in energyexpense at over 70% oflocations. The remaining 30%“We used a thirdparty to validateInnovas’ savingsnumbers and theyturned out betterthan claimed.”Mike O’Malley CoolingPlant Manager5

is split equally with halfexperiencing efficiency lossesabove 10% and half below 6%savings opportunity.How far below?The lowest potential efficiencyimprovement in an evaluatedchiller has been 3.5%.Its payback was still under 3.5years. With the introduction ofthe Helios Tube CleaningSystem , the tube foulingrelated waste can becompletely eliminated.RESULTSConsistent with the results fromother installations, the chillershowed immediate results afterHelios installation, even with asophisticated water treatmentprogram already in place.In 2017, prior to installation ofthe Helios system, the chillerran consistently less efficientlythan it did in 2018 after theinstallation of the Helios.As demonstrated in Figure 1,with a Chilled Water SupplyFigure 1.Chiller Efficiency Comparison from 2017(preHelios) to 2018 (post-Helios) at 75 F EnteringCondenser Water Temperature.6

temperature (CHWST) of 38Fand Entering Condenser WaterTemperature (ECWT) of 75F,the chiller efficiency improvedby an average of 9%.the chiller producing as much as200 tons of additional cooling asshown in Figure 3.When the ECWT increased to80 F, as shown in Figure 2, theaverage chiller efficiencyimproved by 12%. Additionally,the chiller cooling outputcapacity increased due toimproved heat transfer, withFigure 2.Chiller Efficiency Comparison from 2017(pre-Helios) to 2018 (post-Helios) at80 F Entering Condenser WaterTemperature. .Figure 3.Chiller Cooling Capacity IncreasedAs Much As 200 Tons After Helios TubeCleaning System Installation.7

SUMMARYIn 2018 Xcel Energy achievedoptimal efficiency in one oftheir downtown DenverCentral Plant chillers becauseof the adoption of the HeliosTube Cleaning System .The result is significant costsavings and improvedsustainability.Helios offers consistent benefitsincluding energy cost savings,and reduced greenhouse gasemissions.Additionally, the workloadassociated with tube fouling inthe Central Heating andCooling Plant chillers waseliminated.Summary ResultsAverage Chiller Efficiency Gain:Chiller Capacity Increase:Annual Energy Savings:Annual Cost Savings:Project Lifetime CO2 Emissions Reductions:Project Lifetime Savings (15 Yrs)4%Up to 200 tons180,000 kW-hrs 20,0002,200 Tons 410,000Figure 4.Summarized Chiller Efficiency Impactsof Helios Tube Cleaning System Installation.Xcel Energy Case Study – Innovas Technologies8

HeliosTheCleaning CycleThe Helios cycle is fully automaticand controlled by a programmablecontroller.1. Between cycles, the sponge balls are stored in theCollector and all valves are closed.2. At programmed intervals, the Controller commands theinjection valves to open and pump to start, and the ballsare injected into the heat exchanger inlet line.3. Normal cooling water flow transports the balls throughthe heat exchanger tubes and into the Ball Trap.4. The Controller then prompts the collection valves toopen and pump to start, and the balls are returned tothe Collector, where they are held until the nextinjection/collection cycle starts.View the Helios TCS Operation in action atinnovastechnologies.comPrevents scale.Prevents scale, fouling,biological life and corrosion inheat exchanger tubes.Reduces maintenance costs.Reduces maintenance anddowntime costs by eliminatingmanual or chemical tubecleaning.Extends service life.Extends the service life of heattransfer equipment.

The Helios Tube Cleaning SystemThe Helios Tube Cleaning Systemfrom Innovasimproves the energyefficiency of coolingsystems. 1 (877) 897-6564info@innovastechnologies.com2140 Norcor Avenue, Suite 112Coralville, IA 52241See Helios in Action.

sustainable energy future. Specifically, Xcel Energy provides power generation and district cooling services in 8 states in the western, southern and midwestern US. Capable of generating over 17,000 MWs of power, Xcel Energy serves over 3.3 million electricity customers and over 1.4 million natural gas customers throughout its service area.