Baking is the most energy intensive process in the production of baked goods. The amount and type of food in the oven can significantly affect energy usage. Here is how in-store ovens can run at maximum efficiency.
Working towards an energy management plan for shop bakeries should start with monitoring current consumption levels and assessing key areas where savings can be made. For shop bakeries, this starts with the oven.
Over the past decade, in-store/retail baking has been witnessing an exponential development. There is a much wider variety of products, more readily available than ever, from supermarkets, to petrol stations, grocery stores, and other in-store bakeries. Technology innovations have transformed ovens. However, this is why it is very difficult to determine energy savings when comparing technologies over time, particularly when it comes to shop baking. George Schulze, Head of International sales, DEBAG, explained us: “In-store baking 10 years ago was vastly different than today: the products have changed, the variety of products has by far increased, and so have the volumes manufactured. This translates into longer baking times, even with programs designed to be as versatile as possible and suit different products. For example, you would need two baking programs should you produce pretzels and bread. With a combination of two ovens, you could even bake them at the same time. If we add croissants and a type of snack to the list, the energy consumption might even be doubled, but this is purely due to the higher variety of products being baked.”
Another factor in the oven’s energy consumption that applies specifically to shop baking, is preparing frozen goods. Although some of them need to be thawed, they can mostly be baked directly from the freezer, with a core temperature of the products of -18˚C. However, they do require more energy in the process, compared to products starting at room temperature.
Ovens are designed with energy efficiency in mind; features that help optimize resource consumption in DEBAG’ s ovens include the blueprint of the door:
“The three-layer glass integrated in the oven’s door was a feature we introduced with the DILA family of ovens, which is now returning with our new series, the DECON in-store baking ovens. It makes a significant impact on the outside temperature of the oven, which is very important given the location where they are operated, not only to preserve energy, but to ensure the safety of the operator at the same time,” explains Schulze.
Other features that make baking efficient include heating the oven itself, which, depending on air pressure, takes about 5 minutes to reach 200˚C.
Using a semi-automated loading trolley is another energy saver. In the case of the DECON ovens, for example, “The trolley is not rolled in, which means this stainless steel does not need to be heated up. The trolley is brought close to the oven instead and the loading basket is pushed from it into the oven. Doing this for a 5- or 10-tray oven will take well under 10 seconds when done by a trained operator,” adds the specialist. This means that there will be almost no energy loss as a result of opening the door. In addition, the door’s lock-mode allows air to ventilate at the end of the baking program, pulling in the air from the baking chamber while it is 2-cm open. This also limits the risk over over-baking the product.
Timing Makes Perfect
Various parameters can be set and automated to optimize in-store baking to specific needs.
The night baking mode and the auto-on options can be set to have the first batch ready baked, and the oven pre-heated for the day’s work, once the operator reaches the facility. In addition, a stand-by function can also be employed, for a pre-set amount of time, at a default temperature of 130˚C in the case of the DECON technology, but customizable, as Schulze tells us: “The oven can be set to go on stand-by after 30 minutes, and to turn off automatically after one hour, for example, to save energy.”
The ThermoOil Concept
A different example of oven technology comes from Italian specialist Tecnopool: the ThermoOil Spiral oven. While absolute consumption comparisons of oven technologies over time would only work when linked to product specifications, “It is nevertheless possible to evaluate the energy savings between the ThermoOil Spiral oven and traditional conveyor ovens in the region of 30%, according to the products’ baking curve,” Alessandro Cunial, Sales Manager, Tecnopool illustrates. “The ThermoOil Concept, together with the Spiral Concept are key features that grant sensible energy savings and reduced maintenance costs,” he adds.
Tecnopool’s oven can be equipped with almost any type of fuel for which a burner is available since it is only required to heat up the Thermo Oil of the circuit. As baking times, baking cycles, downtimes also influence energy consumption, there are several factors and features that help reduce downtimes and energy consumption. “The ThermoOil system is characterized by a limited Delta T° between the air temperature in the oven and the oil temperature in the heating pipes; this temperature difference results in a more efficient use of the burner. The low inertia grants a quick transfer of the heat, resulting in a faster warm-up of the oven thus reducing the downtimes in production,” Cunial tells us.
You can read more in our print magazine European Baker & Biscuit (May/Jun 2018)!