Steven Carlson, P.E. CDH Energy Corp. Evansville, WI ASHRAE Chicago, 2006 Energy Benchmarking

Presentation Overview What Benchmarking as an Energy Management Tool Why Identify savings potential Prioritize where to look for improvements How Comparison options – Metrics – Data Sources

My Background (Biases?) Building Performance Technology Demonstration Metric Development Commissioning Monitoring & Verification Energy Management Feasibility Studies Energy Simulations

Benchmarking - History Business: Total Quality Management "Benchmarking - a continuous, systematic process for evaluating the products, services, and work processes of organizations that are recognized as representing best practices for the purpose of organizational improvement." Michael J. Spendolini, The Benchmarking Book, 1992 Identify actions to improve performance Identify issues (metrics) Collect Internal data (baseline) Collect External data (comparison framework) Analysis Implement change Monitor Impact

Building Energy Benchmarking Energy Management Tool How am I doing? Relative to previous performance Relative to portfolio Relative to national average Relative to a standard (“Best Practices”)

Define Performance A Meaningful Metric Rich dataset for comparison – Compare to what? – Data source? – Comparison method? Normalize for unmanaged characteristics – Building Area – Building Use – Level of service - Outdoor air volumes - Comfort - Hours of use - Etc

Metrics Often normalized to area Energy Cost ($/sqft) Energy Use (kBtu/sqft) Source / Site ? Electricity / Gas ? Related to... Weather, Sales (meals served, beds), service level Desire to include multiple factors f (floor area, hours per week, occupants, etc) Change in Rank Order Financial No normalizing factors – stay the same Scale: Whole building vs system level Often devised based on type of available data

Self Reference Comparison to past performance More of a diagnostic than a “Benchmark”, but valid energy Management tool Validate project impact Can look at small sub-system

Self Reference Isolated from “Best Practices” No comparison to others Only relative sense of performance over time Recommissioned

Internal Reference Internal data source (small organization) Tabular ranking for small number of buildings Example notes A/C characteristic Example notes electricity price variation (load factor) Energy pricing impacts cost metrics

Internal Reference Internal data source (large portfolio) Rank similar properties Implied similar characteristics Can quantify benefit of reducing large users to norm See only internal best practices

External Reference Comparison to large scale data Industry associations Census data Limited by existing data sets Data by others / analysis black box Normalizing Characteristics Weather, Floor Area, Use, etc Type of Comparison Ranks / Distributions Regressions Standard / Best Practices

External Reference Direct Data Comparison Comparison of residence hall to CBECS micro data Data representative of... Broad classifications Broad age range Limited Sample Wide Range in EUI Representative?

External Reference Direct Data Comparison Typical $0.60/sf Good $0.48/sf Industry specific data set (WI Schools) WI-centric, doesn’t look at other states CA looking to benchmark all commercial buildings

External Reference Let others develop method Energy Star Multi-parameter Representative sample of sector Rank specific to building parameters Source energy

External Reference Point/Score system: Ranking/Grade (0-100)

How to Use the Information?

Moving Toward Best Practice How is it defined? Target Score / Rating (relative performance) System performance (rules of thumb) – HVAC: sf/ton, cfm/sf, hp/cfm, OA cfm/person, kw/ton – Lighting: W/sf, W/lx Energy Model (absolute standard) How is it achieved? Look at system details Design characteristics (changeable?) Operational parameters (changeable?) Management actions (changeable?) Implementation & Feedback

Best Practice Performance Target: Model

Using Benchmarking Benchmarking isn’t the destination, Just the mile marker Benchmark only hints at potential for improvement The benchmark is a tool Still need to figure out where to go Apply expertise Investigate systems Devise changes Assess performance

Summary Effective Benchmarking Define performance Metrics Define peer group Data set Define comparison method Direct Distribution / Rank / Score Standard (Best Practice) Benchmark only gives the score Use information Investigate why Motivate action Confirm project impact Manage energy use