In a future power system, the ability to manipulate generation and load will be a critical factor in providing a secure and stable supply of electrical energy to consumers. Using a simulation-based approach, this study assesses the ability of thermal storage to help deliver flexibility in the operation of domestic micro-generation technologies without sacrificing householder comfort and convenience. A typical UK detached dwelling is modelled along with its heating system, which features a retro-fitted air source heat pump (ASHP). The model is used to determine the maximum possible temporal shift for different capacities and configurations of thermal storage, taking into account the influence of climate, building fabric, control settings and occupancy. The limits of time shifting are dictated by the living space temperature and the hot water temperature delivered to the occupants. The storage mechanisms examined are: the basic thermal inertia of the building fabric; increasing the space heating set point temperatures to increase fabric storage and inserting a dedicated thermal buffer between the ASHP and the heat distribution system. The simulation results indicate that back-shifting of the ASHP start/stop times of between one and two hours are possible without causing serious discomfort or inconvenience to the occupants
