Entry · Water
Storage capacity (maximum EAR)
How much energy would the reservoirs hold if they were full?
Acronyms: EAR, Stored Energy; ONS, National Electric System Operator; SIN, National Interconnected System.
In one sentence
Energy the reservoirs would hold if they were all full.
Real example
61.5%Portuguese onlyda EAR máximaNature of the data: Calculated
Sep 29, 2026 · National Interconnected System
Source: ONS, EAR Diário por Subsistema. Reference up to Sep 29, 2026. Captured on Sep 30, 2026.
The EAR of the SIN relative to the maximum EAR, the storage capacity with all reservoirs full.
Calculated: Deterministic transformation made by Scrutiniums, with a published formula.
Why it matters
How it is measured
In MWmonth, by subsystem, in the ONS dataset “EAR Diário por Subsistema” (maximum EAR field).
Unit: MWmonth
Not to be confused with
EAR is how much is stored; the maximum EAR is how much would fit with all reservoirs full. The EAR percentage is the ratio between the two, and the denominator changes when reservoirs come in.
Related entries
In the learning paths
See in the panel
Official source
ONSOpen data portal, dataset “EAR Diário por Subsistema” (description and data dictionary)
Literal excerpt from the document
Portuguese only“A Energia Armazenada (EAR) representa a energia associada ao volume de água disponível nos reservatórios que pode ser convertido em geração na própria usina e em todas as usinas à jusante na cascata. A grandeza de EAR leva em conta nível verificado nos reservatórios na data de referência. A grandeza de EAR máxima representa a capacidade de armazenamento caso todos os reservatórios do sistema estivessem cheios.”
Documents accessed and text checked on Sep 28, 2026.