Entry · Market
ESS: System Service Charges
Which charge covers the services provided to the system?
Acronyms: SIN, National Interconnected System; CCEE, Electric Energy Trading Chamber; MME, Ministry of Mines and Energy.
In one sentence
Charge provided for in the trading rules to cover the costs of system services provided to SIN users, including ancillary services, such as generation dispatched outside the merit order due to transmission constraints or for energy security.
Real example
R$ 1.60 billionNature of the data: Calculated
Sep 2025 to Aug 2026 · SIN
Source: CCEE, ancillary service charge (ESS). Reference up to Aug 2026. Captured on Oct 6, 2026. Dataset code at the source: ENCARGO_ESS_ANCILAR.
Sum, by accrual month, of the system service charge types published by the CCEE over the 12 months.
Calculated: Deterministic transformation made by Scrutiniums, with a published formula.
Why it matters
How it is measured
In the observatory, through the monthly sum of the charge types published by the CCEE in the ENCARGO_ESS_ANCILAR dataset, in reais, by accrual month, checked against the MME monitoring bulletin and the InfoMercado.
Unit: R$, by accrual month
Not to be confused with
CDE (Energy Development Account)
The ESS is a charge of the trading rules for the costs of system services; the CDE is a sector fund with an annual budget approved by ANEEL for public policies. They are different bases, and the observatory does not add them up.
PLD (Spot price (Settlement Price for Differences))
The ESS is a charge, in reais by accrual month; the PLD is a price, in R$/MWh by hour. An ESS accrual value is not an amount paid in the month.
What cannot be concluded
- An accrual value is not an amount paid in the month: payment comes later, in the settlement, and goes through the relief with funds from the market itself.
Related entries
See in the panel
Official source
Presidency of the RepublicDecree No. 5.163 of Jul 30, 2004, art. 59, caput and item I (consolidated text, wording in force on Oct 6, 2026)
In other words: the trading rules provide for a charge to pay for the services that keep the system operating, among them generation called outside the cost order due to a grid limit or for energy security.
Literal excerpt from the document
Portuguese only“Art. 59. As regras e os procedimentos de comercialização deverão prever o pagamento de encargo para cobertura dos custos dos serviços do sistema, inclusive dos serviços ancilares, prestados aos usuários do SIN, que compreenderão, entre outros: (Redação dada pelo Decreto nº 9.143, de 2017) I - a geração despachada independentemente da ordem de mérito, por restrições de transmissão em cada submercado ou por razões de segurança energética, a ser alocada aos consumidores com possibilidade de diferenciação entre os submercados;”
Presidency of the RepublicDecree No. 5.163 of Jul 30, 2004, art. 59, items II and III (consolidated text, wording in force on Oct 6, 2026)
Literal excerpt from the document
Portuguese only“II - a reserva de potência operativa, em MW, disponibilizada pelos geradores para a regulação da freqüência do sistema e sua capacidade de partida autônoma; III - a reserva de capacidade, em MVAr, disponibilizada pelos geradores, superior aos valores de referência estabelecidos para cada gerador em Procedimentos de Rede do ONS, necessária à operação do sistema de transmissão;”
Documents accessed and text checked on Oct 6, 2026.