John Lord, right, and Mike Barancewicz, left, check for unauthorized electric usage on June 12 as they inspect a school closed for the summer for energy conservation in Ashburn. (Bill O'Leary/The Washington Post)

The sliver of light leaked out underneath a closed door on the other side of the dark, empty classroom at Cedar Lane Elementary School in Ashburn: a light in a closet left on.

John Lord bounded over. Click.

Extra lights on in the nearby gym. Click, click, click.

“That’s 3.8 cents an hour we just saved,” he said, half laughing at himself, half serious: Loudoun County has 82 public schools (and counting). And even when all the students and teachers have gone home, the electrical meters are still spinning.

“It’s a nickel-and-dime thing,” said his partner Mike Barancewicz, the other energy education specialist for Loudoun’s public school system. “But nickels and dimes add up over [nearly] 10 million square feet of space.”

One school’s savings

Many D.C. area school systems have environmental initiatives, including the hiring of energy managers, “green” school design and, in Montgomery County, a U.S. Department of Education award-winning environmental program. In Loudoun, the emphasis is on changing the culture to reduce energy use.

Loudoun was one of only three school districts in the nation singled out by the Environmental Protection Agency for “sustained excellence” in energy conservation. Forty-seven of the district’s buildings have earned an EPA Energy Star, meaning they operate more efficiently than at least three-quarters of similar buildings nationally. Over the past 20 years, the school system’s energy-conservation program, launched by longtime superintendent Edgar B. Hatrick III with a consulting company, has saved the district more than $51 million, according to school officials.

After a particularly acrimonious budget year, the savings feel all the more critical.

“Money we don’t spend on utilities is money we can use to help students,” said Robert L. Marple, principal of Cedar Lane.

That’s why Lord and Barancewicz obsess about saving energy, cajoling teachers and students alike to keep the lights off and the shades down.

People joke that in schools, you need a purchasing order to get a box of pencils, Barancewicz said. “But anyone can walk into a room and turn on a switch,” even if it’s not needed.

He cast a baleful look at an electrical meter. “This is the cash register,” he said, one with charges most people never see. There can be a $19,000 to $20,000 bill “before you’ve done something to correct it,” he said, “unless you’re vigilant.”

So they’re vigilant.

Every outlet is suspect. Any window could be open a crack. They look for doors propped open, hole punchers left plugged in, ice machines running, air conditioning bumped up a notch or two.

The work goes on all year — auditing buildings, evaluating equipment, speaking to classes. But once pupils leave, the pair can really squeeze out more savings.

Long before the last teachers left their classrooms, taking notebooks and pet frogs home for the summer, Lord and Barancewicz had planned the summer shutdown. They had sent out detailed checklists to each school. Some systems have automated shutdowns. But automated systems can fail, so the pair walk hallways, on weekends, sometimes at 2 a.m.

The program was developed by the company Cenergistic, which also began working with public schools in Prince William County last year. Lord and Barancewicz, who have worked for the schools for almost nine years, cost the district about $237,000 a year.

Barancewicz, who came from the energy industry, has an earnest, measured delivery and ready analogies to explain the science behind their work. Lord, a 6-foot-2 former teacher, seems always on the tips of his toes, just about to crack a joke, or giggle. At home, they have the same blankets-around-the-water-heater fervor they bring to the schools; Lord thinks the power company replaced his meter because his family uses so little energy that it seemed to be broken. He put a thermometer in his Energy Star-rated refrigerator to ensure that it never gets colder than 40 degrees.

Barancewicz said that his wife is so used to his “idiosyncracies” at home that she’s now the one who will show him how much they’re saving on their monthly electric bill. And Lord’s 5-year-old daughter, Emily, lectures people about conservation.

Together, the men are trying to coax a school system, with about 10,000 employees and nearly 70,000 students, into saving energy. They’re not just mandating lights out — they’re trying to change the culture.

So they tease the custodians and chat with them in Spanish.

They show a photo they snapped of an energy executive’s Lamborghini and ask employees to please not help buy his private jet. They show a video Lord shot of his daughter when she was a toddler, snorting in her high chair, and ask them not to be energy hogs. They convince the head repair guy for a soda company that they never want anyone to “fix” the dimmed lights on the vending machines. Ever.

They show kids how a volt­meter still registers “vampire loads,” drawing energy even after a lamp or TV is turned off.

By now, longtime custodian Helen Fitts knows to schedule custodians’ cleaning by zone, limiting air conditioning and bright lighting to the areas where they’re working. Sometimes, new teachers find the list of things they need to do — close blinds, unplug printers — a little overwhelming, Brandon Gauthier said in his second-grade classroom at Newton-Lee Elementary School last week.

But for most of the staff, it’s second nature by now. One zealous teacher — they call him Nature Boy — polices the halls, snapping lights off, leaving Starburst candies for the teachers who remembered their regular shutdowns.

At Cedar Lane last week, Lord and Barancewicz scaled a narrow metal ladder to the roof. Barancewicz crouched by a photo sensor and slid a metal band up a hair, a tiny adjustment that will make the lights in the parking lot turn off earlier in the morning and on later in the evening.

He stopped suddenly at a heat-recovery unit, sticking his hand in to feel the temperature, face stern. “There’s no reason for this to be on right now.”

“That's air-conditioned air leaving the school. That’s air we’ve paid to cool.”

Lord already had his cellphone out. The answer came back quickly: They thought it was off. Some type of automated command hadn’t worked. From a central office, someone turned a switch, shutting off the two massive units.

“Some people go fishing,” Barancewicz said, quietly elated. “We just caught a big one.”

Lord smiled. “We just made a huge savings right there.”