Cal-Arch:
The Web-Based Tool for Benchmarking Energy Use

Goal Statement:
The objective of the Cal-Arch project is to develop a simple web-based commercial building energy benchmarking tool to help Californians understand how their buildings' energy use compares with others.

Results:
Building energy benchmarking is a useful starting point in an energy efficiency project. A number of benchmarking tools are available that utilize national Commercial Buildings Energy Consumption Survey (CBECS) data. California buildings are different from the national building stocks. Cal-Arch is the only tool available that utilizes California's Commercial End Use Survey (CEUS). Cal-Arch provides information more relevant to California buildings. (See http://poet.lbl.gov/cal-arch/ceus.html).

Cal-Arch software asks the user for building type, ZIP code, floor area, annual energy consumption, and site/source preference data. The results are displayed as a histogram of the user's energy use intensity (EUI), as shown in Figure 1. Information is provided to help interpret the results, explain the data sources, and compare with other benchmarking tools.

Figure 1. Histogram of building energy use (Site Energy)

Cal-Arch uses a distributional benchmarking method to query CEUS data. With a simple query, Cal-Arch returns a distribution of energy use intensities, or energy use per square foot. No modeling or adjustments are used; hence, the distribution represents actual energy use in actual buildings. Summary statistics and explanatory information (Table 1) help users make valid comparisons.

Cal-Arch provides a summary of how your building's energy use compares with others and reports on the distribution of EUIs. Additional summary data show the sample size and characteristics of the comparison data set. Whole-building energy, electricity, and gas consumption data are available in separate graphics.

Interested?
LBNL has released an initial version of Cal-Arch at http://poet.lbl.gov/cal-arch.

• Control companies, energy information system vendors, and utilities, can use the Cal-Arch database to provide additional services to their customers.
• Energy Service Companies (ESCOS) and performance contractors can use benchmarking information to communicate energy savings potential to their clients.
• Energy managers and building owners have an ongoing interest in seeing how they compare to others. Researchers and analysts can use the tool to view distributions of energy use across different populations.

Downloads and Links:

• "Benchmarking Tool for California: CAL-ARCH" Brochure (546 KB, 2 pp)
   
• "California Commercial Building Energy Benchmarking - Project Final Report", S. Kinney and M. Piette, Lawrence Berkeley National Laboratory. May 2003. (2.14 MB, 27 pp)
   
• "Energy Efficiency Indicators For High Electric-Load Buildings", B. Aebischer et al, Published in ECEEE 2003 Summer Study Proceedings, St. Raphael, Cote d'Azur, France 2-7 June 2003. (1.11 MB, 15 pp)
   
• Operational web-based benchmarking tool with California data sets
   
• ACEEE 2002 Paper on web-based benchmarking tool with California data sets (871.7 KB, 12 pp)

Contact: Mary Ann Piette, Lawrence Berkeley National Laboratory (LBNL), (510) 486-6286