Energy storage and transmission expansion planning: substitutes or complements?

Abstract

The massive development of energy storage systems (ESSs) may significantly help in the supply–demand balancetask, especially under the existence of uncertain and intermittent sources of energy, such as solar and wind power. Using ESSsas complements of renewable generation has technical and economic consequences in both the short-term operation and thelong-term expansion planning of the grid. The authors propose a transmission expansion planning model that incorporatesdecisions about the expansion of generic ESS units in order to study the interaction between the penetration and location ofESSs and the transmission investment decisions. The problem is formulated as a mixed-integer linear programming model andconsiders different demand blocks and their correlation with renewable generation, to account for the distinct features of thesystem over time. The authors’ results show that ESSs are not only substitutes of transmission assets, but they may also becomplemented with transmission assets depending on the power system characteristics. They use a 27-bus representation ofthe main Chilean network to illustrate the model proposed and to highlight some interesting results about the potentialcomplementarity of ESSs and transmission expansion.