Energy Modeling ToolsJal DesaiNational Renewable Energy Laboratory(NREL)July 31, 2019

Contents1 Why do we need energy modeling software?2 Modeling Inputs in General3 Building Energy Modeling Tools4 Common Energy, Water, and Renewable Measures567NREL 2

Why do we need energy modeling software? In 2018, the residential and commercial sectors accounted for about 40% (or about 40quadrillion British thermal units) of total U.S. energy consumption [EIA, May 2019] Opportunity exists for project teams to utilize energy modeling software to helpevaluate design decisions in terms of life-cycle cost impacts in order to maximizebuilding performance Building energy performance is a function of numerous, interdependent internal andexternal factors, such as material selection, mechanical and electrical systems, solarorientation, climate, and occupant usage Modification of various design components can produce complex interactions that aredifficult to analyze in isolation Building energy simulation softwares provide tools for evaluating energy impactsacross dynamic interrelated systemsSource: 86&t 1Source: modules/13-53 Clevenger.pdf3

Modeling Inputs in General These are the overall steps followed to create an energy modelStep 1 Collects data at the site enough to fully define the building and energy consuming featureso Inputs that are unknown should be highlighted and used as calibration parameterso List of data required to build an energy model– Drawings, as-built– Utility bills– Equipment schedules– Lighting drawings– Square footage– Occupancy (24/7, intermittent, conference rooms, etc.)– Schedule – mechanical and occupancy– Building function, purpose, usageStep 2 Fills out the model and run the simulationo Copies the monthly output tables to an excel spreadsheet and calibrates the model to within 5-10% of themonthly/annual utility billsStep 3 Uses the model to run various “what if” scenarios to calculate energy savings associated with identified energyconservation measures4

Building Energy Modeling Tools

BEopt : Residential Building Energy Modeling ToolThe BEopt (Building EnergyOptimization Tool) software providescapabilities to evaluate residentialbuilding designs and identify costoptimal efficiency packages at variouslevels of whole-house energy savingsalong the path to zero net energyBEopt provides detailed simulationbased analysis based on specific housecharacteristics, such as size,architecture, occupancy, vintage,location, and utility rates. Discreteenvelope and equipment options,reflecting realistic construction materialsand practices, are evaluatedFree Web Download:

Case Study: Kwethluk, AKActual HouseAccording to the model, there is an expected potentialenergy savings of 20 % in the energy efficient home. Thefollowing measured were analyzed in the energy efficienthomes1. Air sealing to 7 ACH502. Low-e double pane windows with high heat gain3. R-60 attic blown-in cellulose4. 100 % LED lightsBEopt ModelBuilding Simulation Output7

eQuest: Commercial Building Energy Modeling Tools The Quick Energy Simulation Tool, or eQUEST is a DOE-2interface which allows users to develop 3-dimensionalsimulation models of a particular building design These simulations incorporate building location,orientation, wall/roof construction, window properties,as well as HVAC systems, day-lighting and variouscontrol strategies, along with the ability to evaluatedesign options for any single or combination of energyconservation measure(s)Free Web Download: : Model RepresentationSource: Image generated using eQUESTeQUEST calibrated baseline energy use estimatesSource: Figures generated using eQUEST8

OpenStudio: Commercial Building Energy Modeling Tool OpenStudio is a cross-platform(Windows, Mac, and Linux) collection ofsoftware tools to support wholebuilding energy modeling usingEnergyPlus and advanced daylightanalysis using Radiance OpenStudio is the front-end of theEnergyPlus EnergyPlus is an energy analysis andthermal load simulation program EnergyPlus is not a user interface. It isintended to be the simulation enginearound which a third-party interfacecan be wrappedSource: ng-energy-modeling9

OpenStudio and EnergyPlus Adoption EnergyPlus directly supports several publicand private sector tools and services. Itsupports additional applications andservices via the OpenStudio Platform10

ResStock :Residential Stock Modeling Tool The ResStock analysis tool ishelping states, municipalities,utilities, and manufacturersidentify which homeimprovements save the mostenergy and money The ResStock software isoffered at no cost, leveragingthe U.S. Department ofEnergy’s (DOE’s) open-sourcebuilding energy modelingecosystem of OpenStudio and EnergyPlus .Free Downlaod:

ResStock: Residential Stock Modeling Tool

RETScreen Renewable Energy Modeling ToolModels renewable energytechnologies and energy efficiency Energy efficiency Renewable energy: Wind power Geothermal power Solar PV Solar thermal Ocean Tidal Wave Other technologies: Fuel cells Micro-turbines Also models conventional combustiontechnologies Steam turbine Gas turbine Gas turbine – combined cycle Reciprocating engineFree web download 3

Related (Non-Building) EnergyModeling Tools

PVWatts Solar PV Modeling Tool Estimates the energy production andcost of energy of grid-connectedphotovoltaic (PV) energy systemsthroughout the world It allows homeowners, small buildingowners, installers and manufacturersto easily develop estimates of theperformance of potential PVinstallations Free web-based tool

System Advisor Model (SAM) for Modeling Renewable EnergyFree software that combines detailed performance and financial models to estimate the cost ofenergy for systemsTechnologies Photovoltaics, detailed & PVWattsBattery storageConcentrating solar powerWindGeothermalBiomassSolar water NAL RENEWABLE ENERGY LABORATORY Behind-the-meterresidentialcommercialPower purchase agreementssingle ownerequity flipssale-leasebackSimple LCOE calculator16

MotorMaster Models motor energy use Extensive database ofavailable motors Free web download s/MMIntl14Setup.exe17

HOMER Energy Microgrid Energy Modeling HOMER (Hybrid OptimizationModel for Multiple EnergyResources) is used to modeland optimize conventionalelectrical generationmicrogrids with a highpenetration of renewableenergy Free and pay versionsavailable pro.html18

Many Free Software Tools Available from NREL

Common Energy, Water, and Renewable Measures

Energy Conservation Measures21

Typical Measures Considered Energy Conservation Measures (ECMs) Heating, Ventilating, and Air-Conditioning (HVAC)LightingPlug LoadsBuilding Envelope Water Conservation Measures (WCMs) Renewable Energy Measures (REMs)– ECMs are typically more financially viable when compared to REMs– REMs can be sized to meet the reduced loads after ECMs are implemented O&M, Commissioning & Re-commissioning22

Behavioral & No-cost ECMs Analyze utility rate structure and track billing history Run an energy awareness campaign, promoteoccupants to: Turn off lights in unoccupied rooms such as break rooms,private offices, conference rooms, etc.Turn off exterior lighting during daytime hoursWash hands, dishes, etc. with cold waterTurn off computers at nighttime; use automatic powersettings when they’re inactiveEliminate and remove personal printers, refrigerators,coffeepots, etc. Use setback temperatures on all HVAC equipment23

Energy Conservation Measure HVAC Install programmable thermostats for all zones and HVAC equipment.Install high coefficient of performance (COP) cooling system.Replace regular fan and motor belts with cogged V-belts.Regularly replace HVAC filters.Convert constant air volume (CAV) system to variable air volume (VAV) system.Reduce outside airflow as per ASHRAE 62.1.Implement chilled water reset.Install variable frequency drive (VFD)Incrementally replace old motors with NEPA premium efficiency motors.VFDSource: Santek Systems24

Energy Conservation Measure Lighting Replace all incandescent and CFL bulbs with LEDsReplace all T-12 fluorescent lamps and magnetic ballasts with low wattage T8 lamps and electronic ballasts or LED replacementsImplement task lightingInstall LED exit signsInstall occupancy sensors in common rooms, corridors, restrooms, etc.Install light sensors on exterior lightingReduce lighting level in over lit areas by De-LampingInstall wireless lighting controls Plug Loads Select Energy Star office equipment and appliances.Use network printers to reduce the number of personal printersActivate power management on computers and monitors.Use laptops and LCD monitors instead of desktops and CRT monitors.Install vending machine misers and remove advertising lighting.Install power management surge protectors in offices.25

Energy Conservation Measure Building Envelope Roofs– Increase the amount of roof insulation– Retrofit existing roof with green roof– Retrofit existing roof with cool roof Walls– Install additional insulation in exterior walls– Seal off all the infiltration points in exterior wall Windows– Replace old or single pane window– Add shading features to south-facing facades for solar shading Doors– Replace traditional doors with revolving doors– Create an entrance vestibule with two doors– Install adequate weather stripping26

Water Conservation Measures Use EPA’s WaterSense labeled products. Purchase EnergyStar Water-Consuming Appliances Toilets Retrofit existing toilets Replace Toilets– Displacement device– Dual flush adapters– Low flow or high efficiency toilet– Composting toilet Urinals Retrofit existing urinals Replace Urinals– Siphonic jet retrofits– Washout/Washdown retrofits– Low flow or high efficiency urinals– Waterless Showerheads Install low –flow showerheads– Atomizer– Pulsator– Aerator mix27

Water Conservation Measures Cooling Tower Install air handling unit condensate recoveryInstall cooling tower duct meter Irrigation Reduce water needs by XeriscapingProcure water from alternate water sourceInstall efficient irrigation system––––Low volume drip systemSub surface drip systemReuse systemWeather based irrigation system28

Renewable Energy Measures Common renewable energy technologies are Onsite Photovoltaic ArrayOnsite Solar Hot Water SystemWindBiomassSolar Vent Preheat29

O&M, Commissioning & Re-commissioning General Operations and Maintenance (O&M)Energy Saving Strategies Verify Operation of HVAC ComponentsCalibrate HVAC SensorsPeriodically Retro-Commission HVAC Equipment Provide a safe and healthy facilityImprove energy performance and minimize energy consumptionReduce operating costsEnsure adequate O&M staff orientation and training.Improve systems documentation Resolve operational problemsImprove comfortOptimize energy useRx does not ensure that the systems function as originally designed The goals of commissioning (Cx) are to:O&M programs targeting energyefficiency are estimated to save 5%to 20% on energy bills without asignificant capital investment. Manycan be achieved with minimal cashoutlays. Re-commissioning (Rx) is an ongoing process to:– Ensures the buildings and systems operate optimally to the currentrequirements30

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Jul 31, 2019 · The Quick Energy Simulation Tool, or eQUEST is a DOE-2 interface which allows users to develop 3-dimensional simulation models of a particular building design These simulations incorporate building location, orientation, wall/roof construction, window properties, as well as HVAC systems, day-lighting and variousFile Size: 2MBPage Count: 31Explore further4 Best Free Energy Modeling Software For Windowslistoffreeware.comEnergy Modeling and Tools Energy Analysis - NRELwww.nrel.govA SIMPLIFIED ENERGY MODELING APPROACH FOR BUILDINGS - AS www.ashrae.orgEnergy Simulation Tools used in Architectural Practice .www.arch2o.comRecommended to you b