Will Hodgman lauded the Apple Isle's green-energy capabilities on Sunday while addressing the annual state Liberal council meeting in Devonport.

Plans are under way for a second undersea Bass Strait power interconnector (Marinus Link) between Tasmania and mainland Australia, with a business case due to be released by the end of the year.

Initial studies estimated the project's capacity at 1200MW but new analysis by state operator TasNetworks indicates 1500MW is possible.

"We are progressing our plans for renewable energy that will blow your socks off. The business case is now even stronger," Mr Hodgman said.

Mr Hodgman said the greater capacity would allow Hydro Tasmania to increase the state's pumped hydro capacity to around 35 per cent more than initially thought.

"That will fuel the battery of the nation, which is now a lot bigger," he added.

Pumped hydro uses cheap electricity to pump water up a hill and into a dam, where it is stored.

When energy demands start to peak during the day, the water can be released downhill through turbines to generate power.

Tasmania transfers power to Victoria through the Basslink cable and produces 25 per cent of the country's renewable power.

But 400MW of available energy cannot be delivered to the mainland due to constraints on Basslink, which is more than 15 years old.

The federal government in February announced $56 million to fast-track development of the Marinus Link project.

Construction is slated to begin in 2021, with the cable coming online in the mid-2020s.

Mr Hodgman said Tasmania remained on track to be fully powered by renewable energy by 2022.

Australian Associated Press