Measuring Standby Power and Energy Efficiency

Measuring power above 20 W is usually accurate, but low-power measurements can be challenging. This application note explains common pitfalls and how to avoid them.

While fossil fuel reserves are constantly decreasing, the costs of energy are on the rise. Saving energy becomes increasingly important for consumers’ buying decisions. One area with a big potential for energy savings is consumer electronics operating in standby mode, since they still drain power from the grid. Whereas every single device only consumes a few watts, the overall energy consumption is considerable.

For several years, power input gets optimized both in normal operation and standby. Standards like EnergyStar, EuP (Energy using Products, directive 2005/32/EU in conjunction with regulation 1275/2008) and others, as well as norms like IEC 62301:2011 or EN 50564:2011 define maximum power input along with the setup for measuring it.