Southeast and Midwest
57.6%(+4.9 pp)
Last 90 days
Measured on September 16, 2026
Will the power bill go up?
Daily stored energy in Brazilian hydro reservoirs, in plain language
Not for now
Reservoirs near the seasonal median suggest no unusual pressure at the moment.
Based on South, the subsystem currently under the most pressure relative to its own seasonal median. The chart further down shows the national figure; this answer instead follows whichever single subsystem is under the most pressure, since the grid is limited by its tightest region, not by the national average.
This is an interpretation of public data, not a forecast. Tariff decisions are made by ANEEL.
Measured data
The big number is stored energy as a percentage of each subsystem's maximum capacity. The value in parentheses (pp) is the deviation in percentage points from the median for this same calendar day across the last 5 years, which is what decides whether a subsystem shows as above, below or in line with the season, not the raw percentage alone.
South
81.1%(-2.4 pp)
Last 90 days
Measured on September 16, 2026
Northeast
72.1%(+15.4 pp)
Last 90 days
Measured on September 16, 2026
North
76.8%(-1.7 pp)
Last 90 days
Measured on September 16, 2026
This year against the previous 5 yearsWeighted national average
Weighted by each subsystem's storage capacity, not a simple average (a plain average would treat a small subsystem as equal to a large one).
How reservoir levels relate to your bill
Brazil generates most of its electricity from hydropower. When reservoirs run low for the time of year, the grid operator leans more on thermal plants to make up the shortfall, and those cost more to run than water. That extra cost is what has historically put pressure on the tariff flag (bandeira tarifária), the surcharge added to residential bills. Higher reservoirs mean less need for thermal generation, which eases that pressure. This page shows where that pressure stands today; it does not predict what ANEEL will decide.