R$ 1.885 per 100 kWh. That is the surcharge that will keep weighing on Brazilian power bills in September, after the national electricity regulator Aneel confirmed on Friday (28) that the yellow tariff flag remains in place. For a household consuming 200 kWh a month, the extra cost comes to R$ 3.77, roughly the price of a coffee with a cheese bread at a bakery.

The surcharge has become routine. The yellow flag has been in effect since May, according to G1, following four straight months of green flag, when bills carry no extra charge.

Understand: what the tariff flags are

Brazil's tariff flags work like a traffic light on the power bill: they show how much it costs to generate electricity in the country that month. Brazil relies heavily on hydroelectric dams, so when rain is scarce and reservoirs run low, the grid must switch on thermal plants, which produce more expensive energy. Aneel adopted the system in 2015 to make that cost transparent to consumers.

The charge for each color is as follows:

• Green (favorable conditions): no surcharge;
• Yellow (less favorable conditions): R$ 1.885 per 100 kWh;
• Red, level 1 (unfavorable conditions): R$ 4.463 per 100 kWh;
• Red, level 2 (very unfavorable conditions): R$ 7.877 per 100 kWh.

According to Aneel, keeping the yellow flag reflects the dry season, with lower reservoir levels and the need to activate costlier thermal generation. In a statement, the agency said that "small changes in habits can help reduce consumption and control spending on the power bill".

The charge applies to all consumers served by distribution companies, except those in isolated grid systems, InfoMoney reports. The surcharge appears as a separate line on each month's bill.