ST. LUCIE COUNTY — In the last two years, the St. Lucie County School District has lowered its electric bill by $2.4 million in part by switching to thermal energy storage systems at five schools.
District officials say they believe the electrical savings will continue as more schools are equipped with the energy-efficient systems, which make ice at night and shut off during the day to save power during high demand periods.
“Four to five years ago we started an aggressive campaign on energy management,” said Marty Sanders, the district’s executive director of growth management, land acquisition and intergovernmental relations during Tuesday’s St. Lucie County School Board meeting. “Our actual dollars spent on electric power went from about $10.6 million to about $8.1 million, about a $2.4 million reduction or a 23 percent reduction.”
On top of those savings, the district has netted more than $1 million in incentive rebates from Florida Power & Light Co. for making the move to thermal energy.
Nancy Flickinger, a governmental account manager with FPL, presented the district with a check for $570,240 Tuesday for installing the systems at four elementary schools.
School and FPL officials developed a strategic plan to reduce the district’s annual FPL expense, Flickinger said. Fort Pierce public schools are powered by Fort Pierce Utilities Authority instead of FPL.
“That plan was designed to reduce that $7 million by a million dollars. The following year that was totally achieved,” Flickinger said. “The following year they did it again and saved another million.”
Thermal energy storage is designed to use the most energy at night when demand, and cost, are lower. Water is frozen at night and stored in large tanks. During the day, the chilled water is pumped back through the system to operate the conditioning.
St. Lucie West Centennial High was the first school to use thermal energy and the district received a previous rebate check of more than $500,000 for that. The district recently added the “ice plants” at Village Green, Bayshore, Savanna Ridge and Rivers Edge elementary schools. Port St. Lucie High is next in line for an ice plant, Sanders said.
The district’s other conservation efforts include installing high-efficiency light bulbs and motion sensors that automatically turn off lights if no one is in a room, Sanders said.
In 2009, budget woes led the district to thermal energy, said John Gillette, the district’s senior project manager.
“We decided saving jobs was important and we needed to have a strategy for reducing the amount of energy consumption,” said Gillette, who added that while reducing energy costs hasn’t been easy, it has paid off.
One way the district has reduced costs is by taking advantage of FPL’s seasonal demand time rate. Since 3 to 6 p.m. Monday through Friday during June through September are when electricity rates are most expensive, the district has cut back on energy usage during those times. “Most of the time energy savings is equated with how much pain a person has to go through. In other words, how much do I have to turn the air conditioner up, how much am I going to have to suffer,” Gillette said. “But we decided to take another approach to that and improve the air quality while also bringing energy down by using more efficient units.”