The Swiss-owned ship, whose name is derived from J.R.R Tolkien's Lord of the Rings meaning "the power of the sun", is pioneering the first solar expedition around the globe.
The mission is to demonstrate that existing renewable energy technologies are reliable and effective.
Manned by a crew of four, the boat departed Monaco last September with a travel route crossing the Atlantic Ocean, Panama Canal, Pacific Ocean, Indian Ocean, the Suez Canal before finally returning to the Mediterranean.
It is currently sailing its Pacific leg, and will dock at Queen Salote Wharf for up to four days next month.
An official welcoming ceremony is due on April 11th, followed by a Sustainable Energy Expo on the 12th and 13th, organized by the Government's Tonga Energy Road Map (TERM) initiative.
"We are more than content with the successful progress of our eco-adventure," said PlanetSolar project founder Raphael Domjan.
"Having crossed the largest ocean of the world only with the power of the sun is another significant proof for the efficiency of renewable energies, showing that we have the technology to change."
Shaped like a Catamaran, the 31metre-long by 15metre-high TÛRANOR is powered by 93.5 KW (127.0 hp) of photo voltaic power with an upper-deck covered with solar panels, weighing only 95 tonnes.
So far, the voyage has covered more than 5,000 km in the course of its Pacific crossing, and more than 20,000 km in total since departing Monaco. The TÛRANOR has since broken the record for the longest distance ever travelled by a solar electric vehicle.
After Tonga, subsequent stops are scheduled for Brisbane, Manila, Shanghai, Hong Kong, Singapore, Mumbai, and Abu Dhabi before heading back to Monaco.
The public will have a chance to view the yacht before it leaves.
Issued by the: Ministry of Information and Communication.