When the news talks about low reservoirs, most companies hear it as distant news. The electricity bill is what brings the real warning, three months later, and by then the decision has already been made for you.
The water crisis and energy supply are connected by a path with public signals that appear months in advance. These signals are the reservoir levels, the tariff flag, and the quality of supply in your region. Follow along to see how to read each one and what to decide before rationing.
Executive summary
- In Brazil, drought rarely causes blackouts, and its effect is to make energy more expensive and increase risk.
- Reservoir levels and the tariff flag are public and anticipate the squeeze by months.
- Those who depend on continuous processes decide early because during rationing equipment becomes scarce.
Index
- Why does drought affect the price before affecting the power?
- What are the three public signals that anticipate the squeeze?
- What does the company decide, and when?
- Frequently asked questions about water crisis and energy
- Conclusion
Why does drought affect the price before affecting the power?
As the Brazilian electricity matrix is predominantly hydroelectric, the system switches sources when it rains little and reservoir levels drop.
This switch triggers thermal generation, which costs more per megawatt-hour than hydroelectric, and the extra cost reaches the consumer’s bill through the tariff flag. This is how the water crisis and energy supply meet in the cash register before they meet in the circuit breaker.
What is the difference between blackout and rationing?
Blackout and rationing are different risks that are often confused.
Power outages due to network failure come from windstorms, lightning, construction, and equipment failure, and happen all year round, with or without drought.
Rationing comes from prolonged scarcity and is a public policy decision, announced in advance. It is rarer, but when it happens it affects the entire region at the same time, and that’s when generation equipment disappears from the market.
The cost comes first, and it is measurable
The tariff flag is the mechanism that passes this extra cost to the consumer, and it changes from month to month according to the system’s condition.
If your operation consumes a lot, the difference between one flag and another over a semester is enough money to pay for a good part of a contingency project, and this increase comes without formal notice.
What are the three public signs that anticipate the squeeze?
The three signs are published and updated by the sector’s own agencies, and you can consult all of them at no cost.
1. The reservoir levels
The National Electric System Operator publishes the storage level of the reservoirs by subsystem, with history, and this is the most direct indicator, which moves slowly and gives time to react.
In this indicator, look at the trend compared to the same period of the previous year.
2. The month’s tariff flag
The flag is announced by ANEEL each month and reflects the generation condition, and a sequence of more expensive flags shows that the system is relying on thermal. This is the signal that leads high-consumption operations to seek Tecnogera, before any rationing announcement.
3. The quality of supply in your region
Regardless of drought, each distributor reports to ANEEL how many hours per year the average customer was without power and how many times. These indicators are the DEC and FEC, defined in the Module 8 of PRODIST.
They vary greatly between cities served by the same distributor, and consulting the one for your municipality is the cheapest step of the entire evaluation.
What does the company decide, and when?
Water crisis and energy supply become concrete decisions in three scenarios, and the response changes according to what your operation cannot afford to lose.
If the process is continuous
Oven, stove, cold chamber, automated line, and server room do not tolerate interruption without loss that goes beyond downtime.
For these cases, the question is the size of the contingency, and sizing begins with the critical load, the subset that cannot be turned off. The working regime of the set follows ABNT NBR ISO 8528, and choosing the wrong regime compromises maintenance.
If consumption is high and cost is tight
When consumption is high, the conversation turns to the cost of energy at the end of the month. In this case, your operation can use its own thermal generation during peak hours, when the rate is more expensive, in an engineering decision with a calculable return.
At Tecnogera, we size this scenario based on the real consumption curve of your operation, because the return depends on how many hours per month the equipment will run.
If the risk is rationing
The risk of rationing is the scenario where a late decision costs more, because when the announcement is made, the entire market seeks temporary energy at the same time.
Those who already have a contract or sized project get through the period, while those who start looking after the announcement end up in a queue.
Frequently asked questions about water crisis and energy
Can the water crisis cause a blackout in my company?
Directly, it is rare, because scarcity makes energy more expensive and increases the risk of rationing, which is announced. Localized blackouts have other causes, such as windstorms, lightning, and network failures, and occur regardless of drought.
How do I know if my region is at risk?
You find out by looking at three public things: the reservoir levels at ONS, the month’s tariff flag, and the quality indicators of your distributor’s supply, which ANEEL publishes by municipality.
Is it worth having a generator just because of the drought?
It depends on what your operation loses per hour of downtime and how much it spends on energy. In continuous processes, the calculation usually closes due to risk, and in high consumption, due to cost during peak hours.
Rent or buy?
Rental is a good solution for a defined period, construction, seasonal contingency and feasibility testing before investing, while purchasing makes sense when the use is permanent and your company wants the asset.
How far in advance do you need to decide?
You need enough time to size, hire, and install without rushing, because in a scenario of announced rationing, equipment availability drops quickly, making an early decision cheaper than an urgent one.
Conclusion
For those running an operation, drought is a matter of cost and risk, and both have public advance notice. The reservoir levels, the month’s flag, and your distributor’s indicator tell you what’s coming with months to spare.
At Tecnogera, we size the contingency based on the critical load and the actual consumption curve, and we work with temporary energy for the period the operation needs it. If your operation cannot afford to stop, request a sizing before the crunch arrives.
Last updated: September 2026.
