The plant's departure date has been delayed by bad weather, Radio New Zealand Pacific reports.
The electric floating plant named Orhan Bey will replace the old 50-year-old plant feed of the Nickel Society (SNL).
A power ship is a special purpose vessel on which a power plant is installed to serve as a power generating resource.
Converted from existing ships, power ships are self-propelled, ready-to-go infrastructure for developing countries.
The ship is the first of its kind in the south Pacific and will arrive in New Caledonia on August 25.
The contract signifies the beginning of New Caledonian's decarbonisation scheme and introduction of renewable energies - also called green nickel.
This mastodon of a ship will ne 140m long, 50m high and 45m wide with more than 50 technicians aboard.
The structure will be operated by highly trained Turkish and New Caledonian specialists and is due to be fully functional by mid-September.
It will float in the water next to the old plant near the nickel factory in Doniambo near Noumea.
A contract between SLN of New Caledonia and Turkey's Karpowership is a first and will help the territory access a new continent and market.
The contract between Karpowership and SLN was negotiated and concluded in three months.
Commercial director for Karpowership, Zeynep Harezi, told reporters the contract marks the start of more opportunities for both countries.
"It is the first contract between New Caledonia and Turkey and a fantastic opportunity for Karpowership.
"They help us access a new continent but also an opportunity for investors and Turkish businesses in New Caledonia."
The journey of the boat from Turkey to New Caledonia will take 45 days, crossing six seas and two oceans.
Even though its internal organs will be smaller than the current power plant on land it will emit 30% less carbon dioxide and will emit less sulphur dioxide emissions as well as having lower noise levels.
This will not, however, reduce the cost of nickel fabrication and electricity.
Karpowership is an enterprise of both Turkish and German governments and the first business to make ships of this kind.