By 2030, the EU aims to reduce greenhouse gas emissions by at least 55% compared to the 1990s level. One way to help to reduce emissions is by limiting energy losses associated with the transmission and distribution of electricity. By improving the efficiency of power transformers, reactors and cabling used in electricity grids, significant energy savings can be made – for instance, it is estimated that half of Denmark’s total electricity consumption could be saved simply through more efficient grid power transformer designs.

To help implement these improvements, the European Ecodesign Directive requires power transformer and reactor manufacturers to prove that their products comply with efficiency regulations, aimed at reducing grid losses. However, obtaining precise and reliable loss measurements is still, today, a challenging task.

Firstly, there is a need for metrologists to develop innovative methods for measuring very small power differences across any artifact being tested. This is critical to ensure the effective monitoring of losses and efficiency. Moreover, there are challenges involved with obtaining high accuracy measurements of power, so that measurement uncertainties do not outweigh the relatively small losses associated with the artifacts in question.

The difficulty of obtaining these measurements can be compounded by the high voltage or high current ratings of grid components. Furthermore, measurements may need to be carried out on-site due to issues with transporting the sizable grid components. Site measurements raise other issues, including maintaining non-invasive connections, i.e. with minimal disruption to a grid installation.