The federal Environment and Energy Department's Australian Energy Update 2019, to be released on Friday, showed Tasmanian energy consumption increased by 1.5 per cent in 2017-18.

That went against a trend of declines averaging 0.5 per cent a year since 2008-09.

The department said manufacturing was Tasmania's biggest energy user - accounting for 42 per cent of all use in 2017-18 - and was responsible for more than half the growth in consumption.

One of the big users, South32, is continuing to ponder the future of its TEMCO smelter at Bell Bay, with a decision expected in October.

State Shadow Energy Minister David O'Byrne recently said: "TEMCO is one of the biggest energy users in Tasmania and, if it closes, fixed transmission costs will be redistributed across the network, which means higher power bills."

The department found 42 per cent of Tasmanian consumption came from renewables in 2017, which was the most of any state or territory.

Oil (34 per cent) and gas (12 per cent) were the other major sources.

Renewables accounted for 95 per cent of Tasmania's electricity generation in calendar 2018, up from 91 per cent in 2017-18.

Hydro (84 per cent) and wind power (9 per cent) were the biggest contributors, followed by natural gas (5 per cent).

Federal Energy Minister Angus Taylor said Tasmania accounted for 2 per cent of Australia's energy consumption, but was an "electricity powerhouse".

He said it provided 59 per cent of the nation's hydro generation and nearly a quarter of its total renewable electricity generation.

"This is why the government is supporting the Battery of the Nation and Marinus Link projects to help realise Tasmania's significant potential to deliver additional dispatchable electricity generation and storage to the National Energy Market," Mr Taylor said.