“That is what we can influence”: Exploring energy time-shifting using an always-on display in households with solar panels

Solar panels add a time component to the energy provision of households. Households equipped with solar systems will experience days and hours of abundance, during which they generate a surplus of electricity, as well as times when they need to purchase power from the grid. This creates opportunities for households to utilize more “free” energy when it is available by shifting activities in time, but while this may be possible for some activities, other practices may be seen as non-negotiable. We report on the deployment of an in-home display installed in nine households with solar panels in the south of Sweden. We conducted two sets of interviews: one before installing the display and another four months post-installation. Our results confirm that the negotiability of a certain energy practice may vary between different households. Washing, dishwashing and charging EV were seen as negotiable by everyone, whereas cooking and hot water use were seen as non-negotiable by most, but not all, the households. The in-home display worked as expected as a trigger and provided feedback for helping shifting the negotiable practices, but not for non-negotiable and it was appreciated by the users for its simplicity.