Brazil, a reference in clean energy, will have to increase generation from fossil fuel thermal plants due to the declining share of hydroelectric plants in its electricity matrix. This stems from the growth of intermittent sources like solar and wind, which require constant backups. Studies project higher CO2 emissions by 2040, though alternatives like batteries are under discussion.
A global reference in clean energy production, Brazil will face an increase in generation from thermal plants powered by natural gas, oil, and coal in the coming years. According to a study by consultancy Aurora Energy Research, the share of hydroelectric plants in installed capacity will drop from 42% in 2026 to 36% in 2030 and 28% in 2040. In contrast, thermal plants—fossil fuel sources linked to global warming—will rise from 10% to 16% in 2030 and 18% in 2040.
The EPE's Decennial Energy Plan, a government-linked entity, confirms this trend: by 2034, over 6% of electricity will come from fossil fuel thermals, up from 3% now, while hydro will fall from 56% to 47%. Experts view these projections as optimistic, anticipating greater thermal use due to climate change impacting rainfall.
The expansion of solar panels and wind turbines requires constant sources for periods without sun or wind. With no new reservoir hydroelectric plants—due to environmental and social impacts—the backup role falls to thermals. "For some years now, we haven't been building plants with reservoirs; the last hydroelectric plants we built were run-of-river, which have low controllability," says Roberto Brandão from UFRJ's Electric Sector Studies Group. "From a practical standpoint, the system will need more thermals."
CO2 equivalent emissions in the electricity matrix will rise to 24 million tons in 2034, from 14 million in 2024, per EPE. Iema compares the 10 million ton increase to a fleet of 25 million new cars driving 10 km daily for a year.
Alternatives include batteries for storage, but the government resists, with cost disputes: EPE estimates R$ 5,000 to R$ 9,500 per kW, while Absae calculates R$ 4,668. "Energy storage in batteries would be an interesting complement," says Fábio Lima from Absae.
Aurora projects a need for 47 GW of flexible sources by 2045, equivalent to over three Itaipus. Rodrigo Borges of the firm notes: "It is possible to reduce emission growth without compromising system security, but this depends on the penetration and speed of low-carbon flexibility technologies." Options include reversible hydroelectric plants with lower environmental impact. Abrage estimates 30 GW of remaining hydroelectric potential, and a new environmental licensing law may ease constructions.
