Home batteries pay back in 5 to 7 years only with a R$1.00/kWh gap between time bands, says ABSAE

Until now, time of use pricing in low voltage was optional, through the Tarifa Branca. The Tarifa Hora Certa, proposed by ANEEL's technical staff on 9 November, automatically enrolls units above 500 kWh/month from 2028. The board is expected to decide in December. ABSOLAR, INEL and ABGD support the change, with reservations about those who have already invested in their own generation.

ABSAE put a number on the debate on 11 November: home batteries only reach a payback of 5 to 7 years with a gap of at least R$1.00/kWh between off-peak and peak, well above the Tarifa Branca differential. The association asks for recalibrated time bands before April 2028.

For those assessing storage, the calendar weighs as much as the tariff. The battery is paid upfront and the return comes from the difference between time bands. Without that delta defined, the payback period does not close, and capital waits for the rule.

Setting the time bands between December and April 2028, when the first phase begins, gives storage a calculation to make. Without it, the price signal arrives before the investment it was meant to trigger.