How to Improve Energy Efficiency Through Benchmarking
- By Ellen Kollie
- June 1st, 2006
Energy-efficient schools are important to school administrators, not only because they use less energy and are more comfortable, but because administrators want to be good stewards of the funds available to pay for energy usage.
The question is: How can administrators know that their schools are energy efficient? The answer is through benchmarking, which is comparing a building’s performance to that of similar buildings. Sounds like a great idea, except that administrators often don’t have the time, data or expertise to perform benchmarking.
The California Energy Commission’s Public Interest Energy Research (PIER) program recently developed a benchmarking system that can be copied by districts across the country. It was created by researchers from the Massachusetts Institute of Technology (MIT) in cooperation with the West Contra Costa Unified School District (WCCUSD) and Pacific Gas and Electric Co. (PG&E). The system included analyzing energy consumption information from 39 elementary schools, five middle schools and five high schools.
The benchmarking system presents energy-use data to help facility managers determine how well each building is performing. In addition, it highlights the best and worst energy users, thus revealing which schools need improved energy conservation measures for energy savings.
If your school district wishes to benchmark energy consumption, just follow these six steps researchers used in creating the benchmarking process for the WCCUSD.
1. Gather data. In this first step, you want to gather a year’s worth of usage data for electricity, natural gas, fuel oil and steam. Work with your local utility company to get any information that isn’t readily available. In the WCCUSD program, for example, PG&E helped the district develop spreadsheets based on the utility’s data.
Keep in mind that, although annual energy bills can be used as energy-performance indicators, identifying problems in systems and in different facilities is easier when analyzing daily consumption patterns. Therefore, installing meters that record energy usage in smaller intervals ? like daily intervals ? provides more accurate information. Sure, this costs some money upfront, but if it helps you achieve more energy-efficient facilities in the long term, which is the goal, then it is money well spent.
2. Tabulate energy consumption. The second step is to tabulate absolute energy consumption per site, per year. This is to be broken down into electricity and natural gas, and it should list total consumption, cost and peak demand.
3. Establish energy intensity indicators. This should be in terms of energy use per unit area and energy use per student. Determine the following: site energy consumption and cost, site energy and cost per student, site energy intensity and cost per unit floor area, energy per student-hour of operation and energy intensity per hour of operation. Also, school statistics regarding student population and density, school schedules and physical building features should be considered. To account for different operating schedules, normalize the number of hours of class per week.
Normalizing the consumption by floor area and number of students, and grouping schools by type was useful because it identified a few buildings that had high energy consumption, says Leslie K. Norford, professor of Building Technology at MIT.That gave the school district’s facility people targets as far as what to upgrade first as part of a countywide, long-term process to improve the infrastructure of their schools.
4. Rank the schools. Create an index that condenses all the figures into one indicator of overall performance. In doing so, you’re creating a single metric that reflects all of the important performance indicators that are of interest. In the index, each school’s position should be computed as the average of the ranked positions of that school under each indicator computed in step three. Then, facilities should be sorted into rank order based on the index in order to determine a specific school’s performance relative to that of the other schools.
5. Identify the poor-performing schools. The rank index reveals the schools that consume the most energy.
One thing that Norford noted in ranking the WCCUSD schools is that high schools consume more energy than elementary schools and middle schools. A poor-performing high school may be the best place for a school district to begin the next step.
6. Create an action plan. Now you’re ready to create an action plan for improving the energy performance of the weakest buildings. First, to determine which building systems might be malfunctioning, conduct an energy audit or place more sophisticated monitoring equipment in those schools. Once you know where the problems are, create an action plan for solving those problems and gaining improved energy usage. The plan is likely to be based on the cost of repairing each problem and return on investment ? gaining the greatest and most immediate improvements for the least amount of money.
Again, this benchmarking method can be applied to any school district in the country. Of course, it’s labor intensive and involves a great time commitment. But, if you get the benchmarking program up and running in your district, you’ll have an exceptional payoff in terms of energy efficiency and thus, cost savings. And, once the program is up and running, be sure to monitor the energy impact of new construction, major renovations and energy efficiency retrofits.
If you’re still asking if benchmarking is worth all the effort, then Norford can answer your question. Some people say that you can’t control what you can’t measure, he begins. But, more broadly, it’s often the case that institutional organizations don’t have a good idea of how much energy their buildings are using. Someone pays the bills, but that doesn’t mean the facilities people are involved or have any sense of which buildings are performing well or better than others. Yet, the facilities people feel the squeeze for building repairs. Therefore, it’s a good idea to focus effort on the buildings that need it most. Benchmarking is a good way of noting which buildings those are.
MaryAnn Piette, MSME, L, a staff scientist at Lawrence Berkeley National Lab, agrees with Norford. Benchmarking is a useful and important task because it involves the process of comparing one school against another or against some distribution of energy data. Facility managers need to know, before they make investments in energy management, how their buildings compare with others.
And, Piette stresses, even schools that perform well can and should be improved upon. This is action-oriented benchmarking, and it says not ‘Where am I?’ but ‘What more can I do?’ she notes. She suggests that facility managers who want to go the distance begin by looking at lighting and HVAC.
By Ellen Kollie