Power
Genneia, Argentina's leading renewable energy company, inaugurated its 129.2-MW San Juan Sur solar plant in San Juan province on Thursday.
The plant in Retamito, in the province's Sarmiento department, required an estimated investment of $110 million and sells its output to large private consumers through the Renewable Energy Term Market (MATER), the framework that allows generators to contract renewable power directly with industrial and commercial users.
It is Genneia's fourth solar development in San Juan, an Andean province at the center of Argentina's copper mining push, and the provincial government presented it as the largest solar plant currently operating in its territory.
According to the company, the plant covers 500 hectares and has 250,000 bifacial panels installed. It follows the Ullum complex, Sierras de Ullum and Tocota III, Genneia's other solar plants in the province.
The ceremony was led by Genneia Chairman Jorge Brito and San Juan Governor Marcelo Orrego, alongside CEO Bernardo Andrews and Sarmiento Mayor Alfredo Castro.
"With this project we reach 350 MW of installed capacity in the province. We continue to strengthen our role as a strategic partner for the development of mining," Brito said at the inauguration.
Orrego said: "That a leading company like Genneia continues to invest and expand its presence in San Juan is a clear sign of confidence in our productive potential and in the conditions we offer for developing large-scale projects."
Commercial Operation Began in April
The plant was already delivering power before the ceremony. In the prospectus Genneia filed in July with the U.S. Securities and Exchange Commission (SEC) as part of its planned listing on the New York Stock Exchange, the company reported that San Juan Sur reached commercial operation in two stages: 60 MW on April 23 and the remaining 69.2 MW on June 5. The inauguration came four months after the plant reached full operation.
The same document details the grid connection. The plant holds priority dispatch for 129.2 MW under the MATER, which secures its access to transmission capacity, and evacuates its output through a 33-kV line to the San Juan Sur transformer station. The substation adjoins the site and is owned by the Provincial Electricity Regulatory Entity (EPRE), San Juan's provincial power regulator.
The regulatory process began with a different figure. Argentina's Secretariat of Energy authorized the plant to enter the Wholesale Electricity Market (MEM) as a generating agent through Resolution 235/2025, published in Argentina's Official Gazette on June 3, 2025, with capacity of 120 MW and a connection at the 33-kV busbars of the new substation, which sections the 132-kV La Bebida–Cervantes line. In January, ENRE, Argentina's electricity regulator, published the plant's request for access to transmission capacity for the same 120 MW through Resolution 7/2026. The prospectus lists 129.2 MW installed.
Expected Output Implies a 33% Capacity Factor
The prospectus includes generation estimates prepared by external consultants for each plant. For San Juan Sur, the P50 value (the annual output with a 50% probability of being reached, which the industry uses as its long-term reference) is 374.1 GWh. The more conservative P90 estimate is 344.3 GWh.
On 129.2 MW, 374.1 GWh equals a 33% capacity factor, according to a Shale24 calculation based on the document's data. On the same basis, San Juan Sur ranks above the Ullum complex (29%) and Sierras de Ullum (28%), and below Tocota III and San Rafael, in Mendoza province, both close to 35%.
The company estimates the plant's output is equivalent to the consumption of about 90,000 households and will avoid emissions of roughly 160,000 tonnes of carbon dioxide a year.
A Portfolio Built Around Future Mining Demand
The $110 million is Genneia's estimated investment for the project, about $0.85 million per installed MW. As of March 31, the company had disbursed $82.8 million, a figure that excludes capitalized interest and right-of-use assets. San Juan Sur is one of four plants covered by the financing of up to $320 million that Genneia agreed in March with IDB Invest, the private-sector arm of the Inter-American Development Bank (IDB).
With the new plant, Genneia's solar capacity in the province reaches 349.2 MW: 82 MW at the Ullum complex, 78 MW at Sierras de Ullum, 60 MW at Tocota III and 129.2 MW at Retamito. Including 450 MW in Mendoza, the company has 799.2 MW of solar capacity in Cuyo, Argentina's central-western region, and its total renewable capacity stands at 1,785.9 MW across wind and solar. According to the prospectus, as of May 31 Genneia operated about 23% of Argentina's installed wind and solar capacity, based on data from CAMMESA, Argentina's wholesale electricity market administrator.
The company is targeting mining as the destination for that power. A report by the IDB, the Argentine Chamber of Mining Companies (CAEM) and the Argentine Industrial Union (UIA) estimated that Argentina's copper mining sector will need 1,500 MW. At the Mendoza Energy Summit in September, Andrews said that demand will take time to materialize: "Until mining demand arrives, which I am also very optimistic about, a few years will go by."