Developers of power plants in Brazil that run on biomass and hydroelectricity won the biggest share of contracts to sell electricity to distributors in a government-organized auction.

Eight biomass developers agreed to build 647 megawatts of generation capacity, according to information on the CCEE electricity trading board website today. The projects, which must go into operation by 2018, will sell power at an average price of 133.57 reais ($56.60) a megawatt-hour, according to data compiled by Bloomberg New Energy Finance.

Developers of hydroelectric dams won contracts to sell power from plants with 618.5 megawatts of capacity at an average rate of 125.4 reais a megawatt-hour, the data showed.

In Brazil’s energy auctions, developers bid down from a preset ceiling price the rate they’re willing to sell electricity. The lowest bidders win contracts to sell power to distributors and move forward with their planned projects. The country gets 81 percent of its power from hydro plants.