Entry · Market
MRE: Energy Reallocation Mechanism
How do hydropower plants share hydrological risk?
Acronyms: GSF, Generation Scaling Factor, the MRE adjustment factor; CCEE, Electric Energy Trading Chamber.
In one sentence
Mechanism for sharing the hydrological risks associated with the electro-energetic optimization of the National Interconnected System (SIN), through the centralized dispatch of electricity generating units.
Real example
In Aug 2026, the MRE plants generated, together, 40,397 MWavgNature of the data: Calculated, against 51,185 MWavgNature of the data: Calculated of physical guarantee modulated and adjusted by the availability factor. The mechanism is this group that shares the water risk; the ratio between the two numbers is the GSF (see the GSF entry).
No Check this number record of its own in this example: the number comes from the panel's published database, which carries the source and the reference date.
Calculated: Deterministic transformation made by Scrutiniums, with a published formula.
Why it matters
How it is measured
It is not a quantity. The result of the mechanism, month by month, is the GSF (see the entry): in the observatory, the generation of the MRE plants divided by the physical guarantee modulated and adjusted by the availability factor, calculated with the CCEE open datasets and checked against the monthly InfoMercado factor in some months of the series.
Not to be confused with
Physical guarantee is the maximum amount of energy of each project that can back contracts; the MRE is the mechanism through which hydropower plants share hydrological risk. In the observatory, the generation of the MRE plants divided by the physical guarantee modulated and adjusted by the availability factor is the GSF.
GSF (Generation Scaling Factor (MRE adjustment factor))
The MRE is the mechanism for sharing hydrological risk; the GSF, also called the MRE adjustment factor, is the monthly number that compares the generation of the plants with the physical guarantee. Talking about the MRE is talking about the mechanism; talking about the GSF is talking about the ratio of the month.
What cannot be concluded
- The InfoMercado glossary defines the mechanism, not the formula of the adjustment factor; the ratio used in the observatory is the one that reproduces the monthly factor published by the CCEE, and the divergence from the 12-month InfoMercado figure is published in the panel.
Related entries
In the learning paths
See in the panel
Official source
CCEEMonthly InfoMercado No. 229 (July 2026), section 12, Glossary, page 12
In other words: the plants share among themselves the risk linked to water, in the context of an optimized and centrally dispatched operation of the interconnected system.
Literal excerpt from the document
Portuguese only“MRE – Mecanismo de compartilhamento dos riscos hidrológicos associados à otimização eletroenergética do SIN, por meio do despacho centralizado das unidades de geração de energia elétrica.”
MME, Power Sector Modernization working group (GT)Report of the Thematic Group on MRE Improvement, July 2019, section on the PCHs in the mechanism, p. 18 of the document and of the PDF
In other words: small hydropower plants can participate in the MRE even without being part of the centralized dispatch, and this helps them reduce hydrological risk.
Literal excerpt from the document
Portuguese only“As PCHs são usinas a fio d’água e não participam do despacho centralizado. A extensão do MRE às PCHs permite a elas mitigar o respectivo risco hidrológico e, portanto, melhorar sua competitividade.”
Documents accessed and text checked on Oct 6, 2026.