Hydropower and wind represented the most important sources in June.
Leftist senator Jorge Robledo says electricity services on the country's Caribbean coast face "serious damage" if the utility is acquired by a private investor.
More businessmen have confessed having paid bribes to public officials during the Kirchner governments. Meanwhile, authorities met with officials from the World Bank to discuss the continuation of works affected by the ongoing probe.
Company executives also raised the prospect of a foray into the energy storage segment during a quarterly earnings call on Tuesday.