SEU (Significant Energy Use) is energy use that accounts for a substantial share of total consumption or offers considerable potential for improving energy performance. It may be a machine, a line, a technology or an entire system.
How significant energy uses are determined
First, you establish where the energy goes: which equipment and processes consume how much, and how consumption changes over time. A Pareto ranking is usually applied (a few of the largest consumers account for most of the consumption). The potential for savings is then assessed, for example based on equipment age or fluctuations in operation.
For each SEU, ISO 50001 requires identifying the factors that influence it and assigning it indicators (EnPI) and attention in operational control.
Example from manufacturing
In a paint shop, significant energy uses include curing ovens and dryers; in a welding shop, welding power sources and robotic workstations; in the energy centre, compressors and cooling. For compressors, it usually turns out that a large share of consumption goes on idle running and compressed air leaks outside shifts.
How metering helps
Without sub-metering, SEUs are determined by estimation. Metering by feeder and machine provides the basis for the Pareto analysis, consumption profiles and the search for off-hours consumption. For this purpose, the Energy Infra Scan platform offers an overview of significant energy uses and machine consumption patterns.
Frequently asked questions
Is an SEU the same as the largest consumer?
Not necessarily. A significant use may also be a smaller piece of equipment with great savings potential. Both consumption and room for improvement are decisive.
Do significant energy uses have to be reviewed?
ISO 50001 requires the organisation to update the energy review and the SEU list whenever significant changes occur, so that they reflect reality.