Air Force Base Sees Savings Take Off After Installing Submeters
A 150-acre expanse of government offices, research and development labs, military housing, and other facilities, the base is a prime example of how an electronic submetering system can accurately track energy usage, focus conservation efforts, and recoup operating costs. On the tenant side of the base's submetering project, the same data is used to implement dramatic cost savings that can have a real impact on an enterprise's bottom line.
Before submetering was implemented in 1993, one master utility meter measured energy usage for the entire base. Energy manager Ed Wilson, of the base's civil engineering department, explained, "We knew we were using a lot of energy. We were trying to determine where it was being used and what time of day we were using most of it."
Certain base occupants obviously used more energy than others did. At the time, Aerospace Corporation, an independent technical advisor for Department of Defense space programs, used considerable energy in conducting research, development, and testing of nuclear lasers, space-based sensors, and satellite program simulations.
"Historically, labs use a lot of energy," Wilson said. "At that particular time, Aerospace was using as much energy in one building as we were using for the entire Area A site, which consists of six other buildings. They would run tests simulating extreme environments that would go on for weeks, sometimes months, at a time."
Capturing Consumption FiguresAfter looking at several submetering systems, Wilson settled on E-MON Corporation (Langhorne, PA). "I like the idea of standalone units capable of storing the information and battery backup, so we are basically impervious to losing the data stored there. I have a 36-day window to capture data, which leaves me with options," he said.
The system was selected for its diagnostic and profiling features as well as ease of use. Wilson recalled, "What I wanted was an electronic system where I can look at the load profiles. Just looking at numbers doesn't tell me a heck of a lot. If you can actually look at graphs and charts that are time-related, you can see how and when the energy is being used and take corrective action to save more energy."
"After we made our decision, I jumped right in," he continued. "We bought it, installed it ourselves, and were able to see where our energy was going building by building, what was daytime use, what was nighttime use, etc.," Wilson said.
Thirty-six meters were installed at the service entrances of 14 main buildings-all at least 100,000 sq ft. They collect data from the submeters and communication interface units, then relay the data to Wilson's computer via modem. The data accumulators can store information for up to 36 days in 15-min increments or until downloaded to a computer, and the submeters can maintain data in case of a power interruption.
An Award-winning EffortArmed with hard data on energy loads and performance trends, Wilson pinpointed areas ripe for conservation measures and cost containment. Less than three years after submetering went on-line, energy consumption decreased more than 27% from the established 1985 baseline; utility costs decreased 23% from an established 1990 baseline - during a period that saw electricity rates increase by 4.5%. In 1996, his leadership in effecting energy savings and raising energy conservation awareness among base personnel won him the Air Force Materiel Command (AFMC) Energy Award.
And the numbers keep improving. Through additional submetering stations, software upgrades, and increased tenant awareness of simple conservation practices, the base has seen a 33% reduction in energy usage this year from the 1985 baseline. Analyzing energy profiles for each building, Wilson has identified energy-hogging patterns that can be easily reversed by installing energy-efficient devices, or by simply telling tenants to turn off lights and air conditioners when they leave for the day. By making such changes, the base realized a payback on the submetering system in just two years. Overall, the base is spending $1 million less a year on utilities, measured against the 1985 baseline.
"This is a great diagnostic tool, and the perfect tool to use to demonstrate your savings," Wilson pointed out. "Running air conditioners at night in buildings of this size when they're unoccupied is a tremendous wasted cost, and with meters you can see this."
Wilson can now determine more accurately energy cost allocations for those organizations - tenants, partners, and customers - with funds for utility reimbursement. The more revenue generated from entities with these available reimbursement funds, the more resources his department has for base repairs and maintenance, another cost benefit of the submetering system.
Currently, the submeters measure electric energy only, but since the system allows users to interface with any kind of pulse output, future expansion of the submetering project is under consideration. "That's one of the good things about submetering," Wilson concluded. "It tends to make tenants more conscious of their energy usage and the need to save it. If you have a meter in an area, and you know how energy is being used, you can do something to influence it."ES