PRoR Is Not Seasonal Storage

Claim

Peaking run-of-river (PRoR) is not the same as seasonal storage. Treating PRoR as a substitute for multi-month reservoir regulation is a category error with strategic implications.

Evidence

• Hydropower Fleet Composition uses a 2–6 hrs peaking shorthand for PRoR pondage: valuable for intraday shaping, not for carrying monsoon energy into dry-season months.
• Wet-season surplus versus dry-season scarcity is a multi-month problem; the governed operating summary retains a dry-season hydro band of ~1,100–1,300 MW even as monsoon capability is much higher.
• Daily pondage does not re-time bulk energy across seasons unless it is paired with much larger effective storage or another balancing resource.
• The evidence therefore supports separating intraday flexibility from inter-seasonal energy inventory.

Confidence rationale

High because the distinction is definitional in hydropower engineering (pondage volume and hours of storage vs seasonal carryover). Debates remain over how much daily peaking helps operationally, not over whether PRoR equals seasonal storage.

Unresolved issues

• Some PRoR designs couple with upstream regulation or cascades in ways that blur public labeling—taxonomy needs care in Hydropower Fleet Composition.
• Optimal mixed portfolio (PRoR + storage + trade) is an open planning question; this claim only blocks a false equivalence.

Boundary Conditions

• This claim does not say PRoR is useless. It says PRoR is not seasonal storage.
• It does not say daily peaking has no operational value. It says intraday flexibility is different from inter-seasonal energy inventory.
• It does not reject mixed portfolios. Optimal combinations of PRoR, storage, and trade remain open planning questions.
• It does not say every PRoR project is mislabeled. It says taxonomy needs care when PRoR is coupled with upstream regulation.

Related

• Run-of-River Hydropower
• Storage Deficit
• Firm Power