Laurel Brunner’s Verdigris Blog: Digital Printers & Energy Efficiency

The Bavarian Ministry of Economic Affairs in Germany is funding a new Fogra project to look at the energy efficiency of small and large format digital printers.

This project is evaluating different digital printers (excluding textile machines) in order to quantify how much energy they use. Fogra has based its method on existing approaches to evaluating power consumption in conventional presses. This is intended to provide some sort of control against which the performance of digital printing devices can be assessed. For digital printers Fogra has also included peripheral equipment and specified the measurement cycle. This is a very exciting initiative and, depending on how their testing works and the robustness of the method, it is one that Fogra wants to put forward to be turned into an international standard.

This is important work because different print sectors and production models obviously have different energy requirements. Fogra is basing its evaluation on what they consider to be a representative system configuration, in order to evaluate power consumption and energy usages. This could vary depending on the print mode for instance, or on the output format. There are also the specifics of electrical and power considerations, including the power connection and connection type, the maximum load a system can take in terms of amps and the input voltage. It also important to know the distances between power outlets and machines as this will influence power consumption.

Fogra has categorised digital printers according to the applications they are designed to produce. They are considering energy and power consumption for three different print modes: standby, print ready and production. The basis of measurement is either in A4 sheets per kilowatt hour or square metres per kilowatt hour. Various criteria affect power consumption such as whether the machine is cold when printing starts, substrate weight and passage through the machine, the top printing speed, how much pressure is required to print a substrate, the substrate size and the nature of the inks used. For instance, inks might be very fluid and require immediate drying. There might also be energy usage for pretreating substrates.

Once the project is completed Fogra will produce a guidance document that explains how to measure “operational specific energy consumption”. No doubt this document will also form the basis of some sort of testing service Fogra will offer.

The Fogra work provides printers and publishers with a tool they can use as part of a carbon footprinting study or for Life Cycle Analysis. It has the potential to provide a defined method that can be used in any digital printing scenario, much as the energy consumption of household appliances is measured using the Energy Star rating system.

Laurel Brunner