Capacity of flexible loads for grid support: statistical characterization for long term planning

Flexible loads are a valuable resource for the power grid of the future to help with balancing demand and generation. A balancing authority (BA) needs to know how much flexibility a load has, meaning what type of power deviation (from the baseline demand) signals are feasible for the load. In this work we present a characterization of capacity for a flexible load in terms of the power spectral density of the power deviation. We then show how this characterization can be used for resource allocation for the grid by determining what portion of the grid’s needs can be met by a collection of such loads. The key difference with prior work on flexibility characterization is that ours is posed in terms of the statistical properties grid’s net load and load’s demand deviation, not on specific instances of these signals. The proposed characterization can thus be used for long term planning.