This article examines imperfectly competitive investment in electric power generation in the presence of congestion on the transmission grid. Under simple yet realistic assumptions, it precisely derives the technology mix as a function of the capacity of the transmission interconnection. In particular, it finds that, if the interconnection is congested in one direction only, the cumulative capacity is not affected by the congestion, while the baseload capacity is simply the uncongested baseload capacity, weighted by the size of its domestic market, plus the interconnection capacity. If the interconnection is successively congested in both directions, the peaking capacity is the cumulative uncongested capacity, weighted by the size its domestic market, plus the capacity of the interconnection, while the baseload capacity is the solution of a simple first-order condition. The marginal value of interconnection capacity is shown to generalize the expression obtained under perfect competition. It includes both a short-term component, that captures the reduction in marginal cost from substituting cheaper for more expensive power, but also a long-term component, that captures the change in installed capacity. Finally, increasing interconnection is shown to have an ambiguous impact on producers' profits. For example, if the interconnection is congested in one direction only, increasing capacity increases a monopolist profit. On the other hand, if the line is almost not congested, it reduces oligopolists' profits.
- D61: Allocative Efficiency • Cost–Benefit Analysis
- L11: Production, Pricing, and Market Structure • Size Distribution of Firms
- L94: Electric Utilities
TSE Working Paper, n. 13-432, September 19, 2013