How to save the equivalent of Sweden’s annual power consumption

The global power consumption of refrigerators alone offers annual potential savings of 172 terawatt hours (TWh) without any negative impact on performance. The energy saved adds up to more than a country like Sweden consumes every year. The technology behind it is the inverter.

From icebox to energy-saving chips

Gourmets in ancient times had ice brought from mountain regions to cool their wine and keep food fresh. In Germany, the iceman delivered block of ice until the 1950s. After that, the modern, electric refrigerator took over, as did energy consumption.

According to market researchers, there were around 1.33bn refrigerators worldwide in 2015, most of them old appliances. Each of them uses an average of around 480 kilowatt hours (kWh) per year. Even a nine-year-old television only consumes an annual 160kWh when used for four hours a day. That means the refrigerator is still one of the major power guzzlers in the home and the basic technology remained unchanged in decades. A conventional motor knows only 'on' and 'off' and, accordingly, has just two power levels: no power or full power. Full power means the highest power consumption. Added to the purchase costs are the often significant electricity costs across the entire service life – and the negative impact on the environment.

Energy-saving chips are already reducing power consumption in many new appliances by more than 30%: semiconductors regulate the current flow and adjust the motor performance to suit actual need. The basis for this is an inverter, which is why experts talk about 'inverterization'.

Speed regulation instead of on and off

The principle behind it is simple: For an appliance to work efficiently, sensors constantly measure data – in the case of the refrigerator, for instance, temperature, humidity and motor speed. A mini-computer, a so-called MCU, uses this data to calculate the required control commands. The power chips or power semiconductors translate these into the ideal compressor speed. This is far more efficient than always switching the motor completely on or off.

To ensure that smart home appliances become the standard in future, Infineon is developing semiconductors for this inverter technology. The example of the refrigerator illustrates how much power can be saved. 'Inverterization' reduces power consumption by an average of 144kWh per year. With 1.2bn old refrigerators, that means global potential annual savings of 172TWh. That is also more than the power consumption of all German households.

Worldwide, state-of-the-art energy-saving electronics will gradually be integrated into the other home appliances. But that is not the only area in which energy savings can be made: Lighting accounts for 20% of global power consumption. Using LEDs and lighting control this could be reduced by two thirds.