Green Gravity lab in Port Kembla aims to produce renewable energy using weights, old mine shafts

An artist's impression of how the Green Gravity lab will look at the new site at Port Kembla. (Supplied: Green Gravity)

What seems like a simple plan — sending a large weight down a deep hole — could help Australia towards net zero emissions.

Housed in an old mine shaft and suspended by a strong cable, a weight is lowered 500 metres down a long drop and in doing so, turns a turbine that creates electricity.