Virtual Energy Storage from Air Conditioning Loads

Abstract

It is often said that energy storage holds the key to the power grid of the future due to the highs and lows of uncontrollable generation caused by intermittent renewable sources such as solar and wind. We argue that many loads can offer the same service as batteries. With appropriate intelligence, loads can manipulate demand around a nominal baseline consumption so that the increase and decrease of demand around that baseline appears like charging and discharging of a battery. Loads thereby can act as virtual energy storage (VES) systems. A frequency domain approach is useful to describing the tradeoffs between VES capacity and consumers’ quality of service (QoS). We describe a way to characterize the VES capacity of loads in terms of its power spectral density and analyze the case for air conditioning loads in particular.