Blackout Due to Renewable Energy Surplus? Understanding the Paradox of the Brazilian Electric Sector

Elétrica Sustentável Automatizada
Oct 24
4 min read

The Brazilian electric system is facing an unprecedented paradox: the risk of a blackout, not due to a lack of power, but due to an excess of renewable energy—especially solar and wind—during times of low demand. How did the country, acclaimed for its clean matrix, reach this point? This week’s news about the curtailment of wind and solar power imposed by the ONS (National Electric System Operator) raises a crucial alarm: we are wasting a valuable resource.

In this article, you will find a technical description of the issue, its causes, the role of Distributed Generation (DG), and the most promising solutions to ensure sustainability and energy security in Brazil.

Technical Description: The Imbalance Between Supply and Demand

The risk of collapse, in this case, is not due to a lack of energy, but an imbalance in the grid, a phenomenon known as curtailment.

Aspect	Technical Description	System Implication
Intermittent Generation	Sources like solar and wind depend on climatic factors (sun and wind) and cannot be switched on or off on demand. Generation is high during specific hours (midday for solar, late night/early morning for wind).	Creates a difficult-to-predict and manage surplus, generating energy peaks that the grid cannot absorb.
Distributed Generation (DG)	Micro and mini-generation in residences and businesses (mostly solar), which is not directly controlled by the ONS. It increases energy injection into the grid in a decentralized manner.	Makes controlling and coordinating the energy flow difficult for distributors, worsening the local imbalance.
Low Demand	Energy consumption in Brazil has not grown at the same speed as renewable generation capacity, resulting in a supply surplus mainly during the morning.	Leads to a situation where generation must be curtailed to protect the grid infrastructure.

Causes and Immediate Impacts

Primary Causes

Inadequate Transmission Infrastructure: The transmission network has not kept pace with the accelerated and concentrated growth of renewable generation (especially in the Northeast, where there is high wind power generation).

Lack of Flexibility: The system lacks mechanisms (like large-scale storage) to "bank" the energy generated during peaks and use it when the sun or wind is not available.

Regulation and Control: Distributed Generation (Federal Law 14.300/2022) boosted the market, but the ONS and distributors face difficulties in controlling and monitoring this micro-generation, exacerbating the problem.

Resulting Impacts

Billion-Dollar Losses: Companies in the solar and wind sectors accumulate losses by having their production curtailed and uncompensated.

Energy Waste: Clean energy is simply discarded, contrary to the principle of sustainability.

Investment Insecurity: The unpredictability of curtailments threatens new investments in renewable sources, questioning the system's reliability.

Critical Imbalance Risk: Overload or lack of control in certain areas could, in extreme scenarios, lead to a localized blackout.

Brief History: The Rise of Renewable Energy in Brazil

Brazil has always been renowned for its hydroelectric matrix. However, the scenario has changed drastically over the last 20 years:

Turn of the Century: The matrix was dominated by hydro plants. The risk of water crises (such as in 2001 and 2021) highlighted the need for diversification.

Wind Boom: Energy auctions and the potential of the Northeast boosted wind power, which consolidated as a major source.

Solar Revolution (DG): The Legal Framework for Distributed Generation (Law 14.300/2022) democratized access to solar power, causing it to grow exponentially and become one of the country's largest sources in record time.

Consequence: Brazil achieved one of the cleanest energy matrices globally, but the transmission and storage infrastructure has not been modernized at the same speed, creating the current surplus bottleneck.

Future Occurrences and Solutions (Search Optimization)

Yes, the trend is for curtailment occurrences to continue and intensify, especially during solar peak hours (between 10 a.m. and 12 p.m.), unless structural solutions are implemented quickly.

Solution (High-Value Topic)	Technical Description and Impact	Content Keyword
Energy Storage	Installation of large-scale batteries and distributed systems. Essential for "banking" the excess renewable energy generated during peaks and injecting it into the grid during low-generation periods.	"Batteries for Smart Grids," "Energy storage in electric systems"
Smart Grids	Use of IoT and AI to monitor and manage the grid in real-time. Systems that automatically balance supply and demand, adjusting to intermittency.	"Smart Grids and Automation," "IoT in energy distribution"
Smart Tariffs	Tariffs that incentivize consumption during times of excess generation (e.g., lower midday rates to charge electric vehicles or run machinery).	"Smart tariffs for energy efficiency," "Incentivizing consumption during solar peaks"
V2G (Vehicle-to-Grid)	The technology where electric vehicles can connect to the grid and return energy (stored in their batteries) during high demand or absorb energy during surplus times.	"V2G Technology," "Electric vehicles as energy storage"

The paradox of energy surplus is a clear sign: Brazil is on the right track toward decarbonization, but it urgently needs to modernize the second part of the equation—the transmission and management system.

The solution inevitably involves technological integration: investing in Energy Storage and implementing Smart Grids and IoT. These innovations will not only stabilize the grid and eliminate waste but also consolidate Brazil as a global powerhouse in sustainability and advanced electric systems.