In October, the American Bakers Assosciation and the US Environmental Protection Agency recognized the 18 most energy efficient bread and roll bakeries in the US.
Less obvious but just as pervasive — and essential — throughout the bakery involves the use of compressed air. It’s often overlooked but can be a major contributor to energy waste. “Compressed air usage is undoubtedly the biggest misused energy consumer in any bakery,” Mr. Colliton said. “That’s where the biggest bang can be found.”
Compressed air is used widely throughout a bakery, such as for opening bags before they are filled with product. Air compressors can get product out of pans and can even be used in the makeup area to remove excess flour from the product. These leave room for wasted energy but opportunities for savings. “Literally almost every plant has compressed air systems, and there is a lot of waste that people don’t think about in those areas,” Mr. Marcucci said. “People run more psi than they really need to, and a lot of people don’t realize how many leaks in their air system can really cause them to use quite a bit of horsepower to keep the compressed air system charged.”
CLIF Bar’s Twin Falls plant uses variable-speed air compressors, which help manage lulls in production without wasting energy.
Leaks can be the main culprit when it comes to energy waste. Compressed air leaks can waste up to 20 or 30% of a compressor’s output, Ms. Marsh explained. The good news, however, is that they are relatively easy and inexpensive to repair. Flowers Foods’ first initiative of its Smart Saves program reduced compressed air leaks. “Our engineering team performed compressed air surveys at bakeries to identify leaks wasting energy,” she said. This continues annually, with the company conducting air-leak audits to confirm that each bakery has a monitor-and-repair program. These savings made such an impact in one plant that the local utility company took notice.
“Recently, one of our bakeries had a win-win result when it saw significant savings from efficiency improvements to an air compressor system and leak repair,”
Ms. Marsh said. “We also were awarded an incentive check from their utility provider for work on these projects.”
Bakers can also look for places where compressed air is being used but may not be necessary. In some areas, specifically dough makeup, Northeast Foods has replaced compressed air with centrifugal blowers. “We use direct-drive blowers rather than compressed air to remove the flour from dough pieces,” Mr. Colliton said. “That uses a lot less energy.”
When compressed air cannot be replaced, however, some of the waste can be put to good use. Air compressors generate a lot of hot air. Instead of losing that hot air to the atmosphere, it can be redirected back into the plant to heat water or even heat parts of the bakery that get cold in the winter. “Otherwise you’re just heating the neighborhood,” Mr. Marcucci said. Alpha Baking has put discharges in its air compresses to reuse that waste heat in the winter. This redirection of waste heat can also be applied to the biggest generator of heat in a bakery — the oven.
Keep reading to learn how to more efficiently heat your bakery.