The Northern smelter will reduce power usage of between 30 and 40MW for up to five months.

BBA general manager Ray Mostogl said Tasmania currently faced a challenging time due to the combination of historically low dam storage levels, the lowest spring rainfall on record and the extended outage of the Basslink cable.

''We have reached an agreement with Hydro Tasmania on the best energy savings measure we can provide to assist with managing Tasmania’s energy security during this difficult time,'' Mr Mostogl said.

''BBA has more than 60 years of history with Hydro Tasmania.

''As the state’s largest consumer of electricity we have been in negotiations with Hydro since the Basslink outage occurred to ensure this measure minimises the impact on the smelter’s viability,'' he said.

Mr Mostogl said the company was not planning on reducing its permanent workforce, but the reduction of power usage could affect the number of contractors working at the site during the five month period. 

''We will work with our national and international customers, Hydro Tasmania, state government, suppliers and the local community to minimise any impact,'' he said.

''Potentially there may be redeployment opportunities available for some contractors from BBA to support Hydro Tasmania with work on additional generation assets.''