DC Velocity - April 2017

s p ec i a lr ep or t

E NE RGY - E FF I CI EN T FA C IL I TY D E SI GN

42 DC VELOCITY APRIL 2017 www.dcvelocity.com according to Swisslog. Just as hybrid automobiles recharge their batteries by braking at stoplights, AS/RS cranes, miniload cranes, shuttle systems, and conveyor lifts can generate their own electricity. They do this by using their motor as a generator, creating electricity from friction when braking.

The electricity they generate can then help power the unit itself or even be shared with others.

Energy recuperation offers considerable potential for savings. For example, AS/RS cranes can cut their energy draw as much as 20 percent by powering their horizontal motion using the electricity recuperated by their own downward vertical motion, according to Swisslog.

Likewise, shuttle systems can cut their power consumption by 20 percent by timing the acceleration of one shuttle to occur at the same time that another shuttle hits the brakes.

3Slow down and lose the weight. Automated conveyor systems con- sume the most electricity while they are running at high speed, so facilities can save serious money by automatically throttling down the systems during off-peak periods, a Swisslog analysis shows.

One way to capture those savings is by installing photo eyes that determine when a section of conveyor is idle, then send that signal through an Io T network to a central controller, the company said.

Particularly effective in large-scale systems with thousands of feet of powered conveyors, these systems can save significant power by switching off certain conveyor zones—or even a specific motor on a single roller—when not in use.

Another way to cut the amount of electricity consumed by mobile material handling systems is to put the machines themselves on a diet. In recent years, some manufacturers have redesigned equipment like automated guided vehicles (AGVs) and AS/RS stacker cranes using lightweight materials, slashing 20 to 30 percent of the vehicles’ weight without compromising their load-carrying capability, said Swisslog. Compared with their heavier brethren, these lightweight machines draw far less power from onboard batteries or the facility’s grid.

4Use smart software to save volts. Heating and lighting are the top two energy drains in warehouses. As a result, the path to power savings usually begins with a few basic steps like installing efficient LED lighting, adding skylights to capture natural daylight, installing loading dock seals and shelters, and adding building insulation.

Once they’ve completed those steps, managers can
squeeze some additional savings out of their operations
through the smart use of software. One way to do this is by
automating the controls for various building functions, said
Norm Saenz, managing director at the consulting firm St.
Onge Co. For example, they might use a warehouse control
system (WCS) to automatically turn off equipment when
it’s not in use.

In facilities that use electric vehicles, software such as lift-
truck fleet management systems can play a big role in ener-
gy-conservation efforts. Among other applications, manag-
ers can use these systems to collect data on battery charging
patterns and power consumption, which they can then
mine for energy-saving opportunities,
Saenz said. For example, the data might
show that switching to quick-charging
equipment would help avoid the power
peaks caused when all of the fleet’s vehi-
cles try to recharge at the same time.
5Soak up the sun. Many industry professionals took notice when UPS Inc. announced plans to install
$18 million worth of solar panels on
facilities around the country—a move
the company estimates will cut each
building’s power bill in half. Drawn by
such promises, an increasing number of
warehouse and distribution facilities are
adding solar panels to their vast expanses
of flat roof.

And it’s not just facilities located in the South. Although it was once thought that solar panels only paid off in sunny desert locations, that’s simply not the case, said Richard Murphy Jr., president and CEO of Murphy Warehouse Co., a family-owned logistics service provider based in Minneapolis. The technology actually works in any environment—from Arizona to Minnesota—because solar panels function most efficiently when they’re cold, he said.

Along with helping trim a DC’s electric bill, solar panels can generate extra savings when a facility hooks them up to industrial batteries that store backup power. Among other benefits, having a reserve power supply on hand might allow a company to avoid buying costly diesel generators for emergencies, Murphy said.

Alone or together, these five creative strategies are helping managers minimize their DCs’ power consumption. The steps require some effort, to be sure, but the payoff can be huge. By giving them a try, managers can not only trim their electric bills, but also “green up” their operations. On top of that, they stand to achieve a quicker return on investment on the automated equipment that is fast becoming essential to meeting today’s demands for lightning-fast distribution and fulfillment.

Editor’s note: To learn more about energy-efficient products for the DC, see our Spotlight on Energy-Saving Equipment in this issue’s Rollouts section.