Tasmanian Energy Minister Guy Barnett will announce on Wednesday that Hydro Tasmania will spend up to $30 million investigating the pumped hydro potential of Lake Cethana and Lake Rowallan, south-west of Sheffield, and the Tribute Power Station, south of Tullah.

Mr Barnett said the investigation would identify "one single pumped hydro project to be ready to go when the second interconnector comes on line in and around 2025".

He also revealed there was significant investor interest in potential Tasmanian wind farm developments, beyond those which were already publicly known.

Mr Barnett said cost estimates for the potential pumped hydro projects were $840 million for Lake Cethana, $900 million for Lake Rowallan and $800 million for the West Coast option.

"Obviously, the purpose of the work is to drill down and … identify the most promising of those three in terms of potential capacity and benefit to Tasmania and the nation," Mr Barnett said.

"The plan is for it to be the first of a number of pumped hydro sites over the next two decades,  and this follows the Prime Minister's announcement and support for Tasmania to be the battery of the nation and his commitment of $56 million to fast track delivery of the Marinus Link, which is the second Bass Strait interconnector.

"We are very pleased federal Labor have publicly committed to the $56 milllion as well."

That money would go towards the planning and approval process for the link and Mr Barnett said a final investment decision would still be needed before the start of construction.

He said the interconnector would unlock progress on pumped hydro and more renewables developments, including wind.

He said the Battery of the Nation project and the second interconnector had potential to bring Tasmania billions of dollars in investment and thousands of jobs, largely in regional areas.

He said the developments would also help deliver low-cost, reliable and clean energy into the market, put downward pressure on prices and improve energy security.

"It's building on Tasmania's natural assets," Mr Barnett said.