Surfing the microwave oven learning curve

The microwave oven has penetrated into many kitchens throughout the world and has substituted old polluting forms of cooking with new cleaner ways. Its exponential market uptake in the residential sector has been realized thanks to substantial cost reductions during its deployment phase, which started more than 70 years ago. Today, the annual production capacity reaches almost 100 million units per year. The cumulative number of microwave ovens produced since their commercial launch in 1947 surpasses 1.7 billion units to date. We express the observed price reduction during the expansion of the microwave oven market by a learning curve, which reveals a learning rate of 20 ± 2%. We project that at least two doublings in cumulative capacity are probably still to come over the next few decades, thanks to both replacements and further market uptake. This additional scale-up could imply close to another 40% reduction in the price of microwave ovens. Despite today’s total installed capacity of around 1.1 TW, the aggregate energy consumption of all microwave ovens in use is low as a result of their limited usage time. This may change in the future if novel applications of microwave technology are implemented, for instance for heating or conversion purposes. A significant increase in energy consumption is likely to be expected if, for example, the technology diffuses in industry or finds its way in the energy sector, for instance as pyrolysis or plasma-generating device. We recommend that innovative microwave technology options are explored in more detail, and that their potential role in the energy transition is further investigated.