Energy prices have virtually exploded in the last two years and have become an even more important cost factor in the milling industry. Bühler supports its customers by having experts examine their mill for energy-saving opportunities and by drawing up a specific plan for implementing the savings measures identified – including a precise cost-benefit calculation.
74% raw materials, 7% capital, 7% distribution, and 12% processing – this was the cost structure of an average large mill (500 t/24h) in 2020. 4% of the 12% processing costs were for energy. Consequently, measures to reduce energy consumption were primarily motivated by environmental policy rather than by financial considerations. This situation has changed radically in the last 18 months. The price of a kilowatt hour (kWh) of energy has risen from just under 0.20 to over 0.40 Euros during this time. This means that the proportion of energy costs in relation to the total costs of a mill has more than doubled, increasing from 4% to 10%. And according to the forecasts of industry associations, a return to the “old” energy prices in the longer term is not to be expected either – there is talk of a price of 0.2 to 0.25 Euros/kWh.
SAVING ENERGY MEANS REDUCING COSTS
After the recent cost hike, the 2022 energy bill for the 500 t/24h mill in our example looks like this: assuming an energy price of 0.15 Euros/kWh in 2020 and 0.35 Euros/kWh in 2022, this results in additional costs of 2.2 million Euros for 240 days of annual operation and a consumption of 92.4 kWh/t. If the total controllable energy consumption was reduced by 10%, 388,000 Euros could be saved annually. This has made “saving energy” a management-level issue.
ENERGY SAVING ASSESSMENT
One of Bühler’s main goals is to supply machines, processes, and plants that are as energy efficient as possible. For many years, Bühler has also been helping its customers to save energy in warehousing, production, and distribution. In association with experts from the Bühler affiliate Bühler + Scherler AG, who specialize in electrical engineering, building automation, and project management for medium and large companies, the electrical engineers and technologists from the Bühler service team have assisted many customers by offering various services for planning and implementing energy-saving measures.
This assistance is now being taken to the next level. Bühler provides a comprehensive service offering thanks to its Energy Saving Assessment (ESA).
A FOUR-STEP PROCESS
The ESA consists of four steps. An initial assessment is carried out remotely. This is crucial for planning an on-site visit. The second step is for a team of two experts to spend approximately a week at the customer’s mill. During this time, they subject the entire process to thorough tests and measurements to detect energy-saving potential, analyzing everything from leaks in the compressed air system to process optimization and system upgrades. The Bühler electrician focuses on identifying savings potential in all electrical devices/equipment, while the process technologist takes care of identifying opportunities for improving energy efficiency by means of process optimization and equipment maintenance or upgrades. Particular attention is paid to pneumatics and aspiration, because the “production of air” is “extremely expensive” in terms of energy compared to other processes.
Estimation of savings potential and preparation of an implementation plan
After the on-site visit and measurements to gather the required data, Bühler experts carry out a thorough data analysis and compare findings to industrial best practices. The Buhler expert team then identifies energy-saving possibilities and estimates the feasibility and actual savings potential based on the customer’s production requirements.
The savings potential is presented to the customer and an implementation plan is drafted based on the customer’s priorities. The implementation plan highlights critical conditions and includes risk mitigation measures to ensure the achievement of the estimated savings.
If the customer prefers to reduce the initial cost of implementation and to mitigate the risks related to sustaining optimal performance, Bühler can offer a performance-based implementation plan. In the performance-based model, the project is in principle financed by the savings achieved. The performance-based implementation plan typically includes measures to ensure that optimal energy efficiency is maintained for years to come. These measures can include elements like continuous monitoring and analysis of energy efficiency, as well as technological advisory and training services to enable the customer’s personnel to run the plant in the most efficient way.