One of the most helpful tools in energy analysis is benchmarking—comparing the relative performance of peer buildings in a property portfolio. The peer portfolio becomes a kind of baseline—a yardstick you can use to measure the energy efficiency of your facilities.
The challenge, of course, is finding and selecting an appropriate peer group that will most clearly highlight energy issues and opportunities. Let’s look briefly at four types of energy benchmarking. You can determine which might be the most helpful to you.
The first benchmarking category is reports provided by your utility provider. These periodic (usually monthly) reports demonstrate how your energy use compares to other customers with the same provider. These types of reports can often serve as a broad indicator of the relative efficiency of your building. Plus, you receive them for free.
However, utility-provided reports might not account for variables relating to your energy use. Without submetering, the report might lack needed granularity. It might contain a number of estimated bills. The benchmarking energy data might simply be raw calculations using the meter reading and multiplier for billing periods of varying lengths.
These types of reports may spur helpful questions, but seldom supply useful answers and are generally not actionable.
The second category of benchmarking reports is ENERGY STAR ratings. ENERGY STAR is probably the best-known building benchmarking system. It is widely used, and some surveys suggest that 85 percent of the adult population in the U.S. recognizes the ENERGY STAR brand.
ENERGY STAR uses a web-based software application (Portfolio Manager) to measure building energy efficiency on a 100-point scale that adjusts for a variety of building types. By defining your building type and related characteristics, and by entering your building utility bill data into Portfolio Manager, you can obtain a benchmarking comparison with closely-matched peer buildings in your geographical region. A favorable benchmarking score (75 or above) grants you eligibility to pursue official ENERGY STAR certification, including a plaque for your building.
Unfortunately, ENERGY STAR can only account for a certain set of energy variables for a limited number of defined building types (currently 15). And even if your building matches one of the definitions, there might be some things that you do in your building that make your building unique in its peer group. ENERGY STAR might not be able to fully account for that type of use. This might make your rating lower, and there would be little you could do about it.
A third category of benchmarking resources is industry-specific reports and/or databases. In addition to government benchmarking, some industry or trade groups supply their own benchmarks within certain spaces (K12 school system, university, industrial, etc.). Often, industry-related benchmarking systems can be more relevant and specific to your building portfolio, which is good. Investigate the links provided below to determine if any of these organizations or resources can help you.
The new ISO 50001 standard is a general purpose energy efficiency standard that is gaining traction in a variety of spaces. The National Association of Energy Service Companies (NAESCO) provides a variety of energy benchmarking resources to its members. The Association of Energy Engineers (AEE) is a trade association of more than 16,000 professionals worldwide, providing members with a variety of tools and resources for energy benchmarking, including seminars on using the ENERGY STAR benchmarking tool. Individual organizations may also maintain significant benchmarking resources.
SRS, an energy consultant for real estate owners, maintains a proprietary peer benchmarking database of over 120,000 buildings that is current through May 2011. By contrast, as of this writing, the U.S. Energy Information Administration’s CBECS survey was still using 2003 and 2007 data, although updated building surveys are being conducted and evaluated. Ask your trade association about available energy benchmarking tools and opportunities.
The final category of benchmarking tools/opportunities are those supplied in energy management software. The EnergyCAP energy management software Groups & Benchmarking feature illustrates several benchmarking characteristics and possibilities:
However, internal benchmarking may have limitations, especially if your organization is relatively small.
Suppose, for instance, that you have two buildings that are benchmarking at the same level in EnergyCAP using use and cost metrics. You might assume that neither building has a problem because of their similarity. However, there could be problems in both buildings. They could have been designed poorly. If the buildings are just about the same age, they might both have very inefficient mechanical systems that are heating and cooling at the same time. You might miss this unless you are comparing with a larger set of peer buildings.
That is where a tool like ENERGY STAR can be very helpful. Your two buildings may look good to you based on several internal peer benchmarking metrics, but what happens when you run the ENERGY STAR comparison? A poor rating using this “external” review may reveal that both of your buildings merit a closer look.
Would you like to find out more about energy benchmarking?