Energy Is Money

Wisely managing energy consumption in machining processes pays dividends. It may even help win contracts.

Energy efficiency is a key factor in total cost of ownership.

At home, nothing concentrates the mind on energy conservation like an unexpectedly high utility bill. In shops and plants, high energy costs can eat into profits. Everyone is aware that energy is a factor in the health of the global environment and the stability of the geopolitical situation.

Users are becoming increasingly aware of the energy costs associated with running their machine tools. Machine tool builders are becoming increasingly aware of energy efficiency as a selling point for their products. An example of one machine tool builder that is focusing on energy conservation to win benefits on multiple fronts is Studer AG, the Swiss-based grinding machine provider and a member of the United Grinding Group.

This company’s efforts entail a multi-step approach that highlights the complexity of the challenge as well as the cumulative savings that are substantial and compelling. Three of the four steps are related to machine design and performance, and one is related to overall asset management. Studer has made energy efficiency a key selling point for its entire line of ID and OD cylindrical grinders. This fact was clear at its recent Motion Meeting 2015 in Thun, Switzerland.

The first step of this approach is about “component optimization.” The builder must choose components that can be produced and assembled using less energy. For example, a polymer granite base can be produced using 40 percent less energy than a comparable cast iron bed. Machine structures must be designed to reduce weight but retain strength and rigidity. Onboard subsystems such as hydraulic pumps, coolant chillers and mist extractors must be chosen for low energy usage in operation. Altogether, this step can garner a 14.8 percent reduction in energy costs.

The second step is about “standby management,” which means keeping the subsystems mentioned above in standby mode until they are needed. The result is a 5 percent energy saving, says the builder. The third step is “process optimization.” Studer sees this as primarily a software function in the grinder’s control system. The concept is to guide operators toward the most efficient plan for a grinding operation. This covers setup reduction strategies, optimal grinding techniques for efficient metal removal, avoidance of scrapped parts and other operational considerations. This step can achieve another 5 percent savings in energy costs.

The fourth step is optional, but has intriguing implications. The company calls this step EE4C, an acronym that stands roughly for “energy evaluation for customer quotation.” The concept is to provide a fee-based service that evaluates, validates and documents energy savings in specific user applications. This documentation supports claims of regulatory or contractual compliance, which can be the deciding factor in winning an important job.

Finally, this focus on energy conservation concentrates thinking on an overarching but often overlooked priority for machine buyers: total cost of ownership. This puts machine value and machine price into perspective.