Brazil unveils first dam-mounted floating solar plant

The world's first pilot project to produce solar energy from hydroelectric dams using floaters was unveiled at Balbina Dam, Amazonas, last week. The project's floating photovoltaic panels are expected to output an initial 1 MW. By October 2017, this could get as high as 5 MW, enough to power about 9,000 homes.

According to the Ministry of Mines and Energy, other countries have produced solar energy from water surfaces before, but with regular reservoirs. In Brazil, this technology will be used in dam lakes to avoid evictions and enable energy storage and drainage by taking advantage of existing substations and transmission lines.

Eduardo Braga, Minister of Mines and Energy, says the hybrid energy project uses primarily reservoir capacity and the existing hydroelectric plant capabilities where output levels are below capacity, like Balbina. “This is a fairly typical case—we have a substation that could be transmitting some 250 MW but is outputting a mere 50 MW. So this means there's an idle 200 MW that we could provide in the form of solar energy, at lower cost, to allow energy efficiency and security and better water management at our reservoirs,” he said.

The study will examine the combined efficiency of the solar power plant operating with the hydroelectric dam and how it influences the reservoir ecosystem. After the study phase, Braga expects an output of 300 MW, enough to power 540,000 homes. “We have to carry out extensive studies, and after that, we hope to get auctions started for float-based energy in our existing reservoirs. With plenty of room to collect solar energy in their reservoirs, our several hydroelectric dams can provide enormous, untapped capacity,” the minister explained.

According to Eletrobras CEO José da Costa Carvalho Neto, the country tends to expand its solar energy production with time, which could ultimately lead to lower electricity bills. Although he could not estimate the amount of the cost savings, he hinted they will be “substantial”.

The share of solar power in Brazil's energy mix is still very small, but should grow to reach five-ten percent, or even more in the coming years, according to José Neto. “These panels have become increasingly cheaper. Solar energy will get very cheap, and this will be reflected in consumer bills*,” he said. Ciro Campos, of the Socio-Environmental Institute (ISA), welcomes the government's initiative because it will help advance the solar energy industry and create a supply chain that will result in jobs and income in a time of crisis.

A similar project with a similar solar power output capacity as Balbina's will be announced for Sobradinho Hidrelectric Dam, Bahia, on March 11.

Translated by Mayra Borges