Central Maine Power Company says the upgrades are complete and will serve customers in Kennebec and Waldo counties.
The utility says it has launched a new substation in South China and a distribution circuit that serves China, Freedom, Liberty, Palermo, Vassalboro and Windsor.
The utility says the South China substation was a $6.5 million investment. The utility also says the upgrades will provide for more capacity and better reliability for homeowners and businesses in the area.
The project's part of about $40 million the utility says it invested in the energy grid in 2016.