app_cross_sectional_BM

Cross-sectional benchmarking application

Introduction

Cross-sectional benchmarking compares the energy used by a building system or component, against a peer group. It is the first step to determine if performance is good or poor, and how much potential there to improve the building's efficiency.

Cross-sectional benchmarking is done by retrieving a score from the EPA's Target Finder. Target Finder is an online calculator that helps architects, engineers, property owners, and property managers assess the energy performance of commercial buildings.

Pseudo-code: Cross-sectional benchmarking

Sample explanatory text: "Scores of 75 or higher qualify for ENERGY STAR Label. A score of 50 indicates average energy performance."

Program findCrossSectionalBenchmark

• Get inputs:
  • times, vector of date-times (typically a time-specific format).
  • loads, vector of power data recorded at times [kWh] (float).
  • natgas, vector of natural gas data recorded at times [kBtu] (float).
  • areaFt2, floor area of building [ft^2] (float).
  • zipcode, 5-digit postal code of building (integer).
  • bldgType, type of building from enumerated list (string).
  • bldgYear, year when the building was constructed (integer).
• Assume:
  • Data include at least two years of observations.
  • Webservice default values, if applicable, are used, in order to limit the number of inputs required from direct users.
  • Default value for bldgType is Office.
• Aggregate data:
  • Separate loads into subsets of data that are 12 months long. Mark years so that the last year ends on the last day in times. For example, if the last observation is on 12-June, then every year should end on 12-June. TODO: Is this true in phase-2 code? Possibly it aggregates by calendar year.
  • Separate natgas into similar year-long subsets.
  • Set years to an empty list.
  • Set yearlyEnergyIntensities to an empty list.
  • For each year currYear, call the appropriate data currYearLoads:
    • Set currYearEnergy to the time integral of currYearLoads.
    • Append currYear to years.
• Generate XML files:
  • Replace keywords in the targetFinderdata XML template with the corresponding data inputs.
    • Set property-zipcode to zipcode.
    • Set property-floor-area to areaFt2.
    • Set property-year-built to bldgYear.
    • Set property-type to bldgType.
    • Set meter-usage to yearlyEnergy.
    • Set meter-type to Electric or Natural Gas.
    • Set meter-energy-units to kWh (thousand Watt-hours) or kBtu (thousand Btu).
  • Return targetFinderdata XML-formatted strings.
• Retrieve Energy Star Score from web services:
  • Pass propertyUse string to generate propertyUse in Portfolio Manager.
  • Query the energy star score and append to PMMetrics.