Optimal Subhourly Electricity Resource Dispatch Under Multiple Price Signals With High Renewable Generation Availability

TL;DR

This paper develops an optimal dispatch strategy considering energy, power, and ramping prices, demonstrating significant cost savings in high-renewable systems through a formal control method applied to North America's grid.

Contribution

It introduces a formal method for optimal sub-hourly dispatch considering multiple price signals, including ramping, for high-renewable power systems.

Findings

Cost savings exceed 25% with 50% renewables.

The method effectively balances energy and ramping costs.

Application to North America shows practical viability.

Abstract

This paper proposes a system-wide optimal resource dispatch strategy that enables a shift from a primarily energy cost-based approach, to a strategy using simultaneous price signals for energy, power and ramping behavior. A formal method to compute the optimal sub-hourly power trajectory is derived for a system when the price of energy and ramping are both significant. Optimal control functions are obtained in both time and frequency domains, and a discrete-time solution suitable for periodic feedback control systems is presented. The method is applied to North America Western Interconnection for the planning year 2024, and it is shown that an optimal dispatch strategy that simultaneously considers both the cost of energy and the cost of ramping leads to significant cost savings in systems with high levels of renewable generation: the savings exceed 25% of the total system operating cost for a 50% renewables scenario.