Queensland may have to buy back electricity infrastructure once the government's long-term lease expires – or continue paying for the state to use it, under its yet-to-be-finalised privatisation plan.

The Electrical Trades Union has long warned Queensland could go down the same path as South Australia, which signed a 99-year lease with a Chinese company, but will have to pay for any new infrastructure or maintenance completed during the term of that lease, when the assets fall back to the government.

Treasurer Tim Nicholls. Credit:Glenn Hunt

Under the South Australian agreement, the lessee can elect to own any infrastructure it replaces over $2 million. If the state government wants it back at the end of the 99-year, it would need to pay full value.

Electricity assets such as generators, transformers, substations, poles and wires usually have a life span of about 50 years.