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Start with the question you want to answer

Curtailment is a reduction in generation that could otherwise have been produced, resulting from operating restrictions. To assess its impacts, examine how much energy was curtailed, when restrictions occurred and which reasons were recorded.

On ePowerBay, you can combine Curtailment Ranking, Plants and Projects searches, Basic Grid Substations information and the Map. Exports allow you to use the results in your own analyses.

1. Identify the most affected developments

Open Curtailment Ranking and select State, Generation Source, Start Month and End Month. Choose wind or solar photovoltaic generation and use the same period when comparing developments.

Examine three indicators:

• Curtailment in MWh: the volume of curtailed generation during the period.

• Generation in MWh: the energy actually generated.

• Curtailment percentage: curtailed energy as a share of actual generation plus curtailed generation.

A development may have a large volume of curtailment and a lower percentage than another. Assess the absolute impact and the intensity of restrictions together.

The ranking helps select cases for investigation. By itself, it does not establish the cause of curtailment or entitlement to compensation.

2. Investigate the plant or generating group

From the ranking, access the generating group associated with the record. In Curtailment, select the year and track monthly cuts, separated by restriction reason codes.

This helps identify whether cuts are concentrated in a few months, persist throughout the year or show changes in recorded reasons.

Continue in Plants and Projects. Use State, Generation Source, Status and Minimum Capacity to select comparable developments. Review their characteristics, associated market participants and connection information.

The Curtailment (ONS) search export provides available data for the developments found, including period, generating group, associated substation and restriction reason. Check record coverage before comparing results.

3. Analyze the connection point and infrastructure

In Basic Grid Substations, search for the substation associated with the development and open its detail page.

In Curtailment, select the year and examine monthly cuts by reason. The substation view complements individual analysis and helps investigate whether different developments associated with the connection point experienced restrictions during the same period.

Also examine connected projects and available infrastructure and works information. Sharing a connection point does not prove that all cuts have the same cause.

Export through Curtailment (ONS) in the search screen and use the chart data export on the substation page to investigate further.

4. Check the context on the map

Open the Map and locate the developments and substation under analysis. In the layer catalog, look for ONS information on power plants, substations and transmission lines.

Combine these layers to view the distribution of developments and nearby infrastructure. Use filters and inspect feature details to keep the geographic scope consistent with your research.

The map helps frame questions: is generation concentrated in the region? Which facilities serve these developments? Are there nearby projects that should also be considered?

Use this geographic view to support your investigation. Proximity between facilities does not replace analysis of operating records.

5. Consider future projects and access requests

To assess expansion, complement your research with the ONS Grid Access Queue and MME Grid Access Ordinances.

These solutions help you examine access-related requests and documents. Combine them with regional projects and infrastructure to organize monitoring scenarios.

[Imagem 6 — Tela da Fila de Acesso à Rede ONS, com uma pesquisa relacionada à região ou ao ponto de conexão analisado e as solicitações encontradas.]

[Imagem 7 — Tela de pesquisa das Portarias de Acesso à Rede MME, mostrando os resultados e o acesso aos documentos relacionados ao recorte analisado.]

Access requests do not necessarily represent operating developments. Likewise, historical curtailment does not automatically predict future cuts.

6. Separate curtailment reasons before assessing compensation

Preserve the restriction classification when working with records:

• ENE: energy-related reasons.

• CNF: electrical reliability reasons.

• REL: external unavailability reasons.

This distinction matters because total curtailed energy is not automatically the compensable volume. Assess event eligibility, project documents and the applicable compensation requirements.

Public Consultation 210/2025 discussed compensation for generation cuts. Subsequently, MME Normative Ordinance No. 140/2026 established procedures for the Commitment Agreement, covering eligible cuts occurring between September 1, 2023 and November 25, 2025.

In October 2026, MME announced that CCEE had released the eligibility list. Being classified as eligible allows the process to proceed, but the effects of participation depend on signing the Commitment Agreement.

Use platform data to organize the technical assessment, keeping historical cuts, financial estimates and eligibility confirmation separate.

7. Export and turn the results into an analysis

Bring together ranking, development and substation data. Preserve identifiers, periods and restriction reasons to avoid duplication when combining files.

Compare changes in curtailment and build financial scenarios with explicit assumptions. Multiplying all curtailed energy by a single price may be an exploratory assumption, but it does not necessarily represent contractual losses or compensation amounts.

For recurring queries, ePowerBay MCP also supports searches of curtailment ranking data, subject to available resources and permissions.

This workflow takes you from an initial comparison to a documented analysis: identify relevant cases, investigate their context and gather information for operating, commercial and investment decisions.

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