Duck Curve
A graph of net electricity demand that shows a deep midday dip (from solar overproduction) and a steep evening ramp (as solar drops off and demand peaks), shaped like a duck.
Why It Matters
The duck curve explains why utilities are shifting to TOU rates with expensive evening peaks and cheap midday rates. It's also why battery storage is increasingly valuable — store cheap midday solar, use it during the expensive evening peak.
Related Tools
Related Topics
Related Terms
Time-of-Use (TOU) Rate
An electricity pricing structure where rates vary by time of day. Peak hours (usually 4-9 PM) have higher rates.
Battery Storage
A system that stores excess solar energy for use when the sun isn't shining, providing backup power during outages.
Peak Demand
The highest rate of electricity consumption (measured in kW) recorded during a billing period. Commercial customers often pay demand charges based on their peak demand.