Optimal Placement of Distributed Energy Storage in Power Networks
Provides a theoretical result for power system operators to simplify storage allocation decisions under deterministic demand and linearized power flow.
The paper proves that for optimal storage placement in power networks with convex generation costs, zero storage should be placed at generation-only buses connected via single links, regardless of demand or network constraints. A counterexample shows this fails for multi-connected generation buses.
We formulate the optimal placement, sizing and control of storage devices in a power network to minimize generation costs with the intent of load shifting. We assume deterministic demand, a linearized DC approximated power flow model and a fixed available storage budget. Our main result proves that when the generation costs are convex and nondecreasing, there always exists an optimal storage capacity allocation that places zero storage at generation-only buses that connect to the rest of the network via single links. This holds regardless of the demand profiles, generation capacities, line-flow limits and characteristics of the storage technologies. Through a counterexample, we illustrate that this result is not generally true for generation buses with multiple connections. For specific network topologies, we also characterize the dependence of the optimal generation cost on the available storage budget, generation capacities and flow constraints.