[EN] Brazil has ONS and CCEE. The U.S. has ISOs and RTOs. What’s the difference?

How the U.S. coordinates a decentralized grid through independent operators

🔹 1. A centralized brain vs. a network of operators

In Brazil, the national electricity grid is operated by a single central body: the ONS (National System Operator), responsible for dispatching generation and maintaining system stability across the country. The market operations are handled by another centralized entity: the CCEE (Electricity Trading Chamber).

In contrast, the United States relies on a decentralized model, where multiple ISOs (Independent System Operators) and RTOs (Regional Transmission Organizations) are responsible for both system operations and market coordination in their own regions.

This difference is key to understanding how each country balances reliability, competition, and regional autonomy.

🔹 2. What are ISOs and RTOs?

Both ISOs and RTOs:

• Are independent, nonprofit entities,

• Operate the transmission system in real time,

• Manage wholesale energy markets (including energy, capacity, and ancillary services),

• Ensure open and non-discriminatory access to the grid.

The main distinction is that RTOs must meet additional requirements set by FERC, including:

• Covering multiple states or jurisdictions,

• Performing regional transmission planning,

• Greater coordination with state and federal agencies.

📌 In practice, both ISOs and RTOs play a critical role in the day-to-day functioning of the U.S. power sector.

🔹 3. Who are the main ISOs and RTOs?

💡 ERCOT is unique: although it functions like an RTO, it is not subject to FERC and is regulated at the state level (PUCT).

🔹 4. What is the Brazilian equivalent?

In Brazil, everything is centralized at the national level. ONS and CCEE operate under federal control, and there is no regional system operator. Market dispatch, transmission access, and energy auctions are coordinated by a few key institutions — giving Brazil a tighter regulatory structure, but also less flexibility.

🔹 5. Why does this matter?

For professionals transitioning between these markets — or companies considering investments across borders — it’s essential to understand:

• How responsibilities are distributed in the U.S.,

• How competition is structured regionally,

• And how different models impact reliability and innovation.

The U.S. model promotes regional autonomy and market efficiency, while Brazil focuses on national coordination and centralized planning. Both have pros and cons depending on regulatory goals and grid structure.

In the next article, I’ll compare Texas and Georgia — two states with radically different market structures: one fully deregulated with retail choice (ERCOT), the other vertically integrated and traditionally regulated.

🔎 What do you think of the decentralized ISO/RTO model?

💬 Would a regional operator structure work in Brazil?

📖 Follow me to continue the series and join the discussion.