Concerns have been raised over the deliberate wasting of energy to provide flexibility after load banks – devices for creating dummy loads to test power supplies such as backup generators – were accepted into an ad hoc service to increase demand on the power grid. The load banks were entered into the Optional Downward Flexibility Management service introduced by National Grid Electricity System Operator as an emergency measure to deal with low demand on the power grid over the summer of 2020 as a result of the coronavirus pandemic.