Transmission and Power Generation Investment under Uncertainty

The challenge of deregulated electricity markets and ambitious renewable energy targets have contributed to an increased need of understanding how market participants will respond to a transmission planner’s investment decision. We study the optimal transmission investment decision of a transmission system operator (TSO) that anticipates a power company’s (PC) potential capacity expansion. The proposed model captures both the investment decisions of a TSO and PC and accounts for the conflicting objectives and game-theoretic interactions of the distinct agents. Taking a real options approach allows to study the effect of uncertainty on the investment decisions and taking into account timing as well as sizing flexibility.

We find that disregarding the power company’s optimal investment decision can have a large negative impact on social welfare for a TSO. The corresponding welfare loss increases with uncertainty. The TSO in most cases wants to invest in a higher capacity than is optimal for the power company. The exception is in case the TSO has no timing flexibility and faces a relatively low demand level at investment. This implies that the TSO would overinvest if it would disregard the PC’s optimal capacity decision. On the contrary, we find that if the TSO only considers the power companies sizing flexibility, it risks installing a too small capacity. We furthermore conclude that a linear subsidy in the power company's investment cost could increase its optimal capacity and therewith, could serve as an incentive for power companies to invest in larger capacities.

Joint work with Nora S. Midttun, Afzal S. Siddiqui, and Jannicke S. Sletten