The timing couldn’t be better to save energy. While driving muchneeded dollars to the bottom line, energy-efficient facilities also help support sustainability goals.
Add the billions of dollars the federal government has set aside for green buildings, energy-efficient retrofits and renewable energy projects as part of the $787 billion economic recovery plan, and you have a golden opportunity. However, finding energy savings that stick can be difficult, especially when belts are tight and investments stalled. But, there’s always more than one way to reach a destination. And, there are expensive and not-so-expensive techniques.
The following nine methods can create a guide for reaching both short- and long-term energy-conservation goals.
1 Light It Up
Retrofitting lighting is one of the more obvious—and relatively easy—ways to cut utility bills. Lights are responsible for up to 50% of a building’s electrical consumption, according to Lou Cerny, vice president of Sedlak Management Consultants in Highland Hills, Ohio.
He recommends converting metal-halide high-intensity discharge (HID) lighting systems to fluorescent T5 or T8 lamps. He also suggests using energy-saving LED exit signs, since they typically use power around the clock.
“Lighting is the low-hanging fruit,” adds Phil Pletcher, manager of supply chain consulting at West Reading, Pa.- based Fortna Inc. “Replacing metal halides with high-intensity fluorescents typically achieves return on investment in a year or less.”
By replacing its 1,000- and 400-watt metal-halide lamps with fluorescent T5 and T8 lamps, a Shamrock Foods distribution center (DC) in Phoenix reduced the energy it used for lighting by 42% per year, according to Sylvania Lighting Services, a subsidiary of Danvers, Mass.-based Osram Sylvania.
2 Turn It Off
Another benefit of fluorescent lighting is the ability to turn off and on quickly, according to Pletcher, and that introduces another energy-saving measure: using motion sensors and controls. Both lights and powered equipment can be set to operate only where and when necessary. For example, deep storage areas can be left dark until employees enter.
“Only turn it on when you need it,” Pletcher advises. Rajiv Saxena, vice president of supply chain solutions at APL Logistics in Oakland, Calif., agrees. “A company can reduce its energy consumption by investing in motion sensors or timers that trigger lights to be on only when people are working there. And, there are comparable controls for heating and cooling systems,” he says.
Controls are also making headway with conveyors and other material handling equipment. Energy-guzzling sortation systems can be controlled by software that reduces speed on certain stretches of conveyor, says Pletcher.
Another energy saver is built right into conveyors. “Motorized drive rollers work on sensors and only turn on when a box is in a zone,” Pletcher explains. “They are more expensive but only power up when needed.”
3 Use Free Energy
Another proven strategy is to take advantage of what nature has to offer. While most immediately connect that concept to solar panels, that’s just one way to leverage natural sunlight.
There are other techniques with fewer upfront costs. Simple solutions like skylights or windows can help knock down electric bills, says Pletcher. And, low-tech tasks like painting decking and pick modules white will enhance existing light by reflecting it.
Paul Evanko, senior vice president of York, Pa.-based St. Onge Co., tells the story of a 550,000-square foot DC that installed daylight sensors near skylights. The sensors automatically adjust light levels as sunlight increases and decreases.
The DC combined the sensors with other energy-efficiency measures, including motion detectors in aisles, T5 fluorescent lighting, insulation in air-conditioned areas and white paint on ceilings. Those efforts resulted in a 44% reduction in energy costs, Evanko says.
New technologies, such as the Apollo Light Pipe from Orion Energy Systems Inc. in Manitowoc, Wis., gather and direct sunlight without using any electricity. The Light Pipe uses reflective, geometrically arranged materials to collect sunlight over long periods of the day.
4 Control the Air
Keeping outside air out and inside air in can result in significant cost savings, too. “Dock doors are a DC’s portal to the world,” says Saxena. “But, each one also can be a gateway to hundreds or thousands of dollars’ worth of temperature loss, and therefore energy waste, every year.”
Saxena suggests installing doors that open and close quickly to prevent air from escaping. Investing in heavier dock doors with more insulation and beefing up dock seals can also help stop energy—and dollars—from disappearing. Even the smallest breaches in dock doors can hike up utility bills.
Regulating the flow of air inside a facility also helps protect energy investments. For example, a single highvolume, low-speed (HVLS) fan circulates air throughout areas as large as 20,000 square feet, according to Christian Taber, applications engineer at Lexington, Ky.-based Big Ass Fan Co., a supplier of HVLS fans.
“The temperature of moving air is perceived as being five to seven degrees cooler than the building’s dry-bulb temperature,” says Taber. “Thus, in the summer months, air-conditioned facilities using these big fans can maintain worker comfort while reducing energy consumption.”
According to the National Bureau of Standards, a facility can achieve a 3% savings for every degree the thermostat is raised during the cooling season. In contrast, running personal fans at individual workstations can cost 20 times more than operating one HVLS fan, Taber says, since the big fans are powered by energy-efficient motors.
In the winter, HVLS fans mix the air, equalizing temperatures from ceiling to floor. As heated air naturally rises, HVLS fans push it back down, reducing heating costs. A facility can gain approximately 3% of savings for each degree of stratification eliminated, says Taber.
5 Cut Travel Distances
Next on the list is smart slotting, which reduces the distance lift trucks travel within a facility, thereby conserving the electricity or fuel powering them, Saxena explains. Placing fast-moving product closer to loading docks is a relatively low-cost, easy way to add dollars to the bottom line.
“The average lift truck logs countless miles per year, including many miles that are probably unnecessary,” he says.
6 Investigate VFDs
An increasing number of material handling professionals are considering replacing motor starters with variable-frequency drives (VFDs) as another way to save energy. VFDs control the frequency of electrical power supplied to AC electric motors.
“When a motor starts in a system that uses motor starters, the motor draws an amount of current known as ‘in-rush current’ to get the motor up to speed,” explains David Voynow, material handling segment manager at Schneider Electric in Palatine, Ill. “This amount of current is higher than the current needed to keep the motor running once it is up to operational speed.”
Voynow explains that utilities bill facilities based on both the actual amount of electricity they use and the greatest amount they use during any half-hour period during the billing cycle. The latter method is commonly referred to as “demand charge.”
“In a material handling system, motors are being turned on and off constantly,” says Voynow. “A system using VFDs can reduce the impact of in-rush current on demand charges by gradually ramping up a motors’ speed, therefore reducing the amount of total current drawn.”
7 Retrofit Motors
As with drives, motors can also save energy dollars. Sedlak’s Cerny describes a concept developed by Dunedin, Fla.-based Miraculous Motors Corp. (MMC) called “ample amps.” The technology, designed for use with AC electric motors, introduces a secondary winding to a motor’s main wiring. The result is a motor that is also a partial generator.
“Retrofitting conveyor motors can bring them from a 65% efficiency level to 90% with a payback of less than two years,” Cerny says.
8 Recover Lost Heat
Additional energy savings can be gleaned from compressedair systems. According to audits by the U.S. Department of Energy, more than 50% of compressed-air systems at small- to medium-sized industrial facilities can benefit from low-cost energy-conservation opportunities.
According to Frank Moskowitz, project manager at Draw Professional Services, a subsidiary of Atlas Copco Compressors in Rock Hill, S.C., compressed-air systems are inefficient, since 85% of the energy used to convert air pressure from zero to 100 psi is released as heat byproduct.
“The most expensive component in the total cost of compressed air is energy,” he says. “That means 85% of the electricity used turns into heat.” That byproduct can be captured by a heat recovery unit and directed back into the facility. Instead of being released as waste, the heat can then be used to produce hot water for washrooms or enhance comfort in workspaces, warehouses, loading docks or entryways.
9 Avoid Future Costs
And, finally, the ninth path to energy savings sounds strange, but it’s logical: Avoid using energy in the first place. According to Fortna’s Pletcher, space utilization in a facility can help avoid future expansions. “Every additional square foot has to be heated or cooled,” he says. “Use high-intensity storage, build up instead of out and consider narrow-aisle or very-narrow-aisle storage.”
Maximizing the cube has a double benefit: It avoids costly renovations and dodges future energy costs.