Engineers to save bigger bucks on AC, lighting

by Tech. Sgt. Kelly White
Joint Base San Antonio-Randolph Public Affairs

10/18/2012 - JOINT BASE SAN ANTONIO-RANDOLPH, Texas -- In today's culture of cost-consciousness, the onus for frugal spending of taxpayer dollars must be the priority for every uniformed and civilian member of Air Education and Training Command, throughout the Air Force, all the way to the top of the Department of Defense.

At Joint Base San Antonio, there's an energy team committed to reducing energy consumption and operating costs - and doing so in ways that result in zero perceived impact on its mission or personnel.

"Our long-term JBSA energy plan includes a blend of technologies that will lower monthly utility bills and increase our maintenance budget for energy-related equipment," Ruben Ramos, 902nd Civil Engineer Squadron energy manager, said.

The plan is called demand side management.

"Large electric utility customers such as JBSA pay a unit cost for each kilowatt-hour consumed, and a demand charge which is the rate (kw) at which those kwh are consumed," Ramos explained. "Utility companies must meet the total peak demand of all customers at all times. If they can't meet customer demand, they either buy additional capacity or curtail customers' use via rolling blackouts."

JBSA's electricity provider, CPS Energy, offers its Demand Response Program.

"Under this program, if JBSA can reduce the rate at which it uses energy during critical periods, specifically noon-7 p.m. daily, June through September, the utility pays JBSA," he said. "It's cheaper for the utility to reward its own customers than to activate an additional generating plant or buy supplementary capacity on the open market.

"Air conditioning is the most expensive electrical load at Randolph, as well as the other JBSA locations," he continued. "The 902nd CES has systematically cycled air-conditioning system components on and off to reduce the total demand during cooling seasons. Since 2010, these 'events' have occurred at Randolph up to 25 times, providing CPS with 200-400 kilowatts, lasting 3-6 p.m. as needed."

Randolph's reward has totaled about $73,000 over the last three years, and the JBSA energy team intends to expand this strategy across all its locations, turning the 300kw from Randolph alone into 10-12 megawatts collectively.

To achieve this, the JBSA energy team and CPS will seek financial means to put thermal energy storage tanks at major chiller plants on each installation that will store cold water needed for air conditioning, while allowing the machines that produce the cold water to be dropped off-line during peak demand periods, Ramos explained.

"The chiller plants will be turned back on to 'charge' depleted storage tanks with cold water during off-peak or evening hours," he added. "By shifting the load and leveling generating profiles, CPS generating plants will run more efficiently, ultimately keeping customer rates more stable."

But the JBSA energy team isn't stopping there.

"The second highest load is lighting," Ramos said. "When thermal energy tanks are added to JBSA and chiller plants run at night, the base load will understandably increase.

"To counter this, we'll improve the efficiency of night-time exterior lighting through solid state lighting, more commonly known as light-emitting diodes, and related controls, across JBSA to lower energy consumption and also become a key tool in demand side management," Ramos said.

This technology cuts energy requirements by considerably more than half and is a light source that can be dimmed or started instantaneously to illuminate roadways, parking lots and building exteriors across the locations nightly, he said. Adding timing devices will result in JBSA's utility bills being significantly cheaper.

For more information about energy conservation, call the JBSA energy manager, Anthony Martinez, at (210) 808-0180 or DSN 420-0180.