Operational flexibility describes a power system’s ability to respond with controllable real power
resources to rapid changes in power balance error. For balancing areas with high penetrations of
stochastic generation, these changes can be large enough to cause operating problems. We create the
tools to quantify and intuitively explore operational flexibility in any power system and apply those
tools to analyze the Federal Columbia River Power System (FCRPS). We chose the FCRPS because
it is a large system with complicated constraints, and because conflicting demands on operational
flexibility have become a regional public issue. We inventory system obligations, map all obligations
and forecasts to constraints in the form of power (MW) vs. time, create data structures and an
algebra for unifying these time series, and assemble an original metric of operational flexibility.
The metric quantifies a common but vague concept of flexibility, intuitively characterizes a power
system, and yields actionable intelligence that dovetails with existing deterministic indicators of
system state. The resulting information-dense summary can improve schedule quality both as a
visualization tool for human schedulers and as a versatile formulation for dispatch algorithms.
