Consumers are the big winners from federal government-owned Snowy Hydro taking on the "oligopoly" of the major electricity suppliers, says chief executive Paul Broad, who says there is a clear case for building new gas-fired power generation.

Mr Broad said that Snowy building a gas-fired power station in the Hunter Valley, as flagged as a possibility by Prime Minister Morrison on Tuesday, would help get more competition into the market against major players such as AGL Energy and Origin Energy, which had been slow to move ahead with new plants.