If you’ve ever waited in a buffet line or been served in a high school cafeteria, you’ve seen them. Rows of metal pans immersed in a bath of hot water.
According to food service industry veterans, restaurants, hotels and school cafeterias typically use inefficient natural gas or electric resistance steam-based systems to heat those pans and keep the food warm.
“With steam, it’s really imprecise. It tends to overcook. The operator’s going to err on the side of turning it all the way up,” said Roger Goldstein, executive director, facilities and energy, Panda Restaurant Group. Goldstein, the energy manager for Panda’s 2,000 company-owned restaurants, spoke at the Electric Power Research Institute’s Electrification 2018 conference in California.
A more efficient way to keep food warm, said David Zabrowski, vice president of Frontier Energy and manager of Pacific Gas & Electric’s Food Service Technology Center, is to eliminate steam as the heat transfer medium and use induction to warm the pans directly.
Panda Group restaurants have already been switching from steam-based food-holding pans to electric induction models.
“By going to an induction technology, it was a great use of an electric product that has digital controls and precise temperature holding,” said Goldstein.
“It allows us to hold the food considerably longer in a much more presentable and fresh way on the line. It saves tons of labor in cleaning and draining and work in the store,” he added.
Testing equipment at an independent lab, in this case the Foodservice Technology Center operated by Southern California Edison, helped Goldstein make the case to company decision-makers that a shift to induction technology made sense. Making these kinds of shifts is all a part of transitioning to an energy efficient economy.
“It takes a lot to sell that technology to the C-suite in the corporate office and have them understand the value,” said Goldstein. “We don’t have a way to evaluate that without either a utility or third-party assessment lab.”
Goldstein presented company executives with data, based on lab testing of the drop-in replacement induction equipment, that bolstered his case.
Lab testing “showed a tremendous savings,” he said. Testing confirmed a steam-based system with 18 to 23 pans consumed 10,500 kilowatt-hours of electricity annually. But a replacement electric induction system consumed just 5,100 kilowatt-hours.
According to Goldstein, the upfront cost of the induction system is five to seven times higher than a comparable steam-based system. But, he said, armed with lab data confirming the 50 percent electricity savings, it was easy to extrapolate the total savings and demonstrate the life-cycle ROI to company executives.
“We were able to show the hard savings in energy and then the soft savings in labor, food quality, and food costs,” he said.
Keeping soup warm with induction warmers
David Zabrowski presented a similar case study for another appliance commonly used in commercial kitchens: countertop soup warmers. Standard models use less efficient electric resistance technology to heat water and warm the metal pan.
But, as with steam food-holding pans, because there isn't good feedback on temperature, operators tend to over-correct, and the soup continues to cook inside the container. With an induction soup warmer, the operator can set the desired holding temperature.
Beyond avoided food waste, the induction warmers deliver an average of 65 percent electricity savings. Standard steam-based soup warmers consume 339 watts, compared to just 105 watts for an induction model, said Zabrowski.
He recounted the example of the owner of a new Indian fusion restaurant in San Francisco who had planned to install a dozen electric resistance steam-based soup warmers. But, before opening, the owner switched to electric induction models that together will reduce the restaurant’s electricity bill by $800 annually.
Zabrowski predicted that just as high-efficiency LEDs have taken over the lighting market, induction technology will come to dominate in kitchens.
Kitchens missing out on energy savings
Even though kitchen operators stand to save energy and money with a move to high-efficiency electric equipment, available utility rebates often go unclaimed. This holds true despite a host of other benefits recounted by Goldstein and Zabrowski, as well as Rio DeGennaro, vice president of Cres Cor, an Ohio-based kitchen equipment manufacturer, including cooler kitchens, faster pre-heating, and faster recovery after cooking.
But energy consumption is generally far down on the list of concerns for harried kitchen operators who have limited time to investigate rebates for more efficient electric equipment.
“While it’s very, very energy intensive, and while energy bills are very, very high, [food service] operators are very much unaware of what they can do to control those costs,” said Zabrowski. He noted that many operators of large kitchens never see an energy bill.
“There’s no sub-meter in the hospital or school for the kitchen,” he said. And because cash-strapped school districts are routinely short of funds for upgrades, inefficient equipment will be in kitchens for a long time, likely decades.
“It appears as if a number of the end users, and those in the [sales] channel and all the salespeople, when I ask them if they’re aware of the incentives available in their own areas – certainly not all – but most of them say, ‘No,’” said DeGennaro.
In California, the Energy Wise website maintains a list of energy-efficient food service equipment that qualify for rebates provided by the state’s largest utilities. But that's the exception.
“For whatever reason,” DeGennaro said, “there’s a disconnect in getting information out."