Forty-six workers were arrested at the Medupi power station in Lephalale following violent protests there, Limpopo police said on Friday.
Brigadier Hangwani Mulaudzi said protesting workers torched an Eskom vehicle and damaged a police vehicle during the protest on Thursday night.
They would appear in court soon on charges of public violence and malicious damage to property.
Last month, Eskom temporarily closed the power station when contract workers went on strike.
Construction of the coal-fired power plant, set to be commissioned in 2015, was also interrupted when workers downed tools in September last year. - Sapa