By Luciano Costa
SAO PAULO, May 9 (Reuters) - Developers have presented more than 150 proposals for power plants ahead of an auction this month to supply electricity to the Brazilian state of Roraima, which has struggled with a rash of blackouts due to reliance on the shaky Venezuelan power grid.
Roraima, which is not connected to Brazil's national grid, has begun depending on expensive emergency fuel-burning plants in the absence of reliable power from its northern neighbor, which has sunk into a profound economic and political crisis.
Brazil's federal government set an auction for May 31 to close long-term contracts with new suppliers using any available source, from oil to wind or solar.
Canadian Solar Inc and Brazilian companies Casa dos Ventos, Eneva SA and Equatorial Energia SA are among the potential bidders, according to industry sources.
In the auction, the bidders offering the lowest price for electricity will win the chance to build the projects in two years and begin delivering power in June 2021.
Together the projects in the running would be enough to generate almost 6 gigawatts, but the government is likely to award the rights to between 200 megawatts and 250 megawatts.
One source said power company Eneva has presented a plan with a natural gas-fired plant. The company would transport gas from the Azulão field in Amazonas to Roraima, using ships or trucks since there is no pipeline in the area.
A second source said Canadian Solar has also entered the auction, as a way to foster demand for its locally produced panels. Another source said Brazilian developer Casa dos Ventos will bid with a solution to generate power from biomass.
Casa dos Ventos confirmed that it has prepared projects for the auction, but said it is still evaluating whether to bid.
Eneva and Canadian Solar declined to comment.
Equatorial could not be reached for comment. (Reporting by Luciano Costa; Writing by Marcelo Teixeira Editing by James Dalgleish)