The Bushehr plant located in Tehran, Iran has it reached 40% of its 1,000MW capacity, after it was connected to the main national power grid in August this year.
The reactor at the $1bn project began operation in May and is expected to generate about 350-400MW of energy.
The energy generated will be about 35 to 40% of the capacity of the national grid, reports AFP.
The Busheher plant was initially expected to commence operations but was repeatedly delayed because of technical glitches and the international dispute.
German company Siemens began construction of the plant in the 1970s but later quit after the 1979 Islamic revolution over concerns about nuclear proliferation.
The nation also said it is ready to negotiate with other countries for the development of more nuclear power projects.