Protecting the national electricity grid balance by temporarily limiting residential customers’ available power: a large-scale experiment

In an effort to ensure the availability of electricity to all their customers during potentially critical periods in winter, French national transmission and distribution system operators (TSO & DSO) RTE and Enedis launched a program in 2022, amidst the global energy crisis, aiming to provide an alternative to load shedding by reducing the power of residential customers for a limited period of time. Temporary Power Limitations (TPL) are designed to occur nationwide, for a maximum of a few hours, when consumption peaks are expected and all other load reduction mechanisms have been exhausted. To dimension the system, the public authorities asked Enedis to conduct a large-scale experiment in February 2024 – not in a context of network stress – by reducing the available power of over 100,000 residential contracts for two hours. The primary goal was to understand customer reactions to such events – how many experienced outages, how many and what type of users adapted their usage, etc. – in order to develop a generalized model for predicting energy savings under real-life conditions. The experiment was deemed an overall success. We identified three categories of users based on their behaviour during the limitation period: those who exceeded the maximum power, those who adapted their usage to avoid outages, and those whose consumption habits remained unchanged. For each category, we built a model to predict energy savings, distinguishing between each customer profile (type of subscription, subscribed power, etc.). These models include a temperature component, accounting for the thermosensitive part of consumption. Under nominal conditions, we estimated that a TPL affecting 10 million customers on a typical winter day would reduce a consumption peak by 2 to 3 GW.