"It is one of the most important issues of achieving rapid progress of the national economy to give definite priority to the electricity production," Kim was quoted by the Korean Central News Agency as telling workers at Wonsan Youth Power Station.
No date was given for his visit to the plant completed in 2008, Yonhap News Agency said Tuesday.
Kim's latest public appearance -- the third this year -- is seen as a follow-up on his New Year message calling for "opening the gate to a great, prosperous and powerful nation by 2012," the 100th anniversary of the birth of his father and North Korean founder Kim Il Sung, the South Korean news agency said.
Kim's first two visits were to military units.
About 100,000 people rallied in Kim Il Sung Square Monday to show support for Kim's military-first policy and projects designed to rebuild the country's industrial infrastructure, North Korean media said.
Recent photos revived speculation about Kim's health, Yonhap said. The latest photos of Kim visiting an artillery unit, released Monday, showed him clapping with his two bare hands. In December, photos showed Kim applauding with gloves on while photos released earlier in the year show his left in a pocket or resting at his side.
Officials in Seoul and Washington said Kim suffered a stroke in 2008 and is recovering.