The cost of construction was 570m roubles ($15.3m), according to local reports.
Kosh-Agach is the first of five solar power stations planned for the region, with their total capacity amounting to 45MW.
"Four of them must be launched in the Altai Republic before 2019, with their aggregate amount of financing being more than 5bn rubles," Russian President Vladimir Putin said during the inauguration ceremony.
"This
