New technology will provide free power to King Island as it aims to prove low-cost energy generation claims.

Wave Swell Energy, a group developing ocean wave energy generation technology, is carrying out commercial validation trials off Tasmania's King Island ahead of a potential listing.

The units are installed at depths of around 10 metres.

The group has built what Wave Swell chief executive Tom Denniss described as "big concrete caverns", which use the constant back and forth flow of the ocean to generate energy.

"As waves pass into the inside of the cavern the water level rises, this causes pressure on the air, which blows open valves at the top of the unit and turns a uni-directional turbine; as the water recedes it causes negative pressure which closes the valves, creating a cyclical process."