Digital Eyes Keep Schools Comfy, Cut Utility Bills
From behind his desk in a converted warehouse near the Ohio Expo Center, Yong In Son monitors about 140 buildings on an array of computer screens. His goal: keeping the temperature comfortable at Columbus City Schools while saving energy.
Son can set and track building temperatures and energy consumption—even down to the motors that spin fans inside school air-handling units.
The district's Energy Management Department can't say exactly what it has saved taxpayers throughout the years, but for a district that spends about $16.2 million a year on utilities, the savings can add up quickly. Columbus schools are expected to save $1.37 million a year through a new electricity contract. In the future, solar panels could become part of the energy mix.
Son and his boss, Energy Management Supervisor Daniel Spence, typically know about problems with any of the district's heating and air-conditioning systems before students and employees in the schools do—the system sends email alerts to their cellphones 24 hours a day.
The system is constantly receiving about 1,200 "inputs"—temperatures, humidity levels, power consumption levels, mechanical failure alerts—on a typical elementary school.
"I can control anything from here," Son said, sitting behind his five computer monitors in an office at I-71 and E. 17th Avenue. In the room next door, the walls resemble the inside of a desktop computer. Every type of computer motherboard and control box used in a school's climate-control systems is wired together as a guide to how it all works.
Since about 2000, when the district went digital with its climate controls with the help of a state grant, it has had the ability to centrally monitor and control all of its buildings in real time through the Internet, Spence said.
For a few years before that, it used a dial-up modem system to periodically log into a building's system, and officials could open and close pneumatic valves to heat or cool parts of a building. Before the mid-1990s, systems were controlled by the building custodians, Spence said.
When a school closes for the night or for student breaks, the office automatically turns down the air-conditioning (or heat in the winter). The system can be programmed to restart certain building areas for meetings and other events, such as basketball games. The department also fine-tunes the time cycles that expensive gas boilers operate on, trying to wring out the most value for every unit of energy, Spence said.
"We focus on the new buildings because those offer more of an opportunity," because they have more and better controls, Spence said.
When the system showed that the new Champion Middle School was using more electricity than expected at night, Son was able to trace part of the problem to school officials' leaving the gym lights on at night, he said.
It's not novel for large organizations to have systems capable of doing what the Columbus City Schools are doing, said David Zehala, executive vice president of business development for Columbus energy-management consultant Plug Smart. What is novel is that the district is apparently taking full advantage of its system, Zehala said.
"It's really how you program it to do what you want to do," Zehala said. "An energy-management system can be an energy manager's best friend because it's all automated. If you don't have an automated system in place to take advantage of the unique problems that school districts face, you could just be writing big fat checks to the utility companies all day long."
The district joined the Ohio School Consortium's electricity contract this spring and knocked about 27 percent off its bill, to about 8 cents per kilowatt-hour, Spence said. The 42 school districts in the consortium bid as a unit, driving down the cost. The new contract was awarded in March and will go through December 2013. The district turned to the consortium as a result of rising rates from AEP, Spence said. Another division of AEP eventually was the low bidder on the new contract.
The office has reviewed offers from private companies to install solar panels on the roofs of schools, but has thus far rejected the required long-term price lock-in as too risky. If the price of electricity were to rise, solar would become more attractive, Spence said.
"Right now, the payback on a solar panel is not that good," he said.
All of the district's new schools being constructed in the current phase of the voter-approved rebuilding project are being designed to accommodate solar panels in the future, including pre-installed conduit that would route the electricity from the roof to the meter, said Carole Olshavsky, chief of district facilities.
Spence can't say exactly how much money the office has shaved off the district's energy bill during the years, but it's immense, he said. Office secretary Mary Lager alone has caught major discrepancies in electric bills amounting to hundreds of thousands of dollars, Spence said.
Last fall, the district was charged between $10,000 and $15,000 per month for electricity at the closed Fifth Avenue Alternative Elementary from October through November. That's up to 400 percent above the expected level, Lager said.
After initially claiming the bills were correct, the Columbus Division of Power and Water agreed to replace the meter and discovered it to be faulty, Lager said.
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