A dynamic household appliance stock model for load management introduction strategies

In this paper, the dynamics of market introduction of new electric household appliances and their gradual propagation into the existing appliance stock is investigated. The study is focussed on the release of appliances that possess a certain new property, in the present case a communication interface for “Smart Grid” applications such as sophisticated load management methods. Understanding the introduction dynamics is particularly relevant for estimating the amount of installed load management compatible household appliances and the available control potential in a given year in the future, which is essential for “Smart Grid” business model development. Due to the relatively long life span of household appliances, it can be shown that it takes up to several decades to achieve a complete replacement of the conventional appliance stock in the absence of additional measures. The focus of the paper is on methodology and application of stock models describing the number of appliances “in the field” over time. Different approaches depending on the availability of input data are illustrated and the effect of additional measures, such as replacement incentives, is evaluated. Results are given for the Swiss market of refrigerators, freezers, and heat pumps.