Studies of underground water tables in Victoria's north and west have revealed a significant new store of geothermal energy reserves.

Geothermal energy is a clean renewable resource and is generated from hot rocks and aquifers deep below the earth's surface.

The State Government and Geoscience Victoria, have undertaken large studies of underground energy over the last year and released a new map of available reserves to attract investment.

The Energy and Resources Minister, Peter Batchelor, says Stawell, Horsham, Mildura, and Ballarat, have all been identified as new areas with significant energy potential.

"These are good results, they're better than we expected," he said.

"We had very limited data available and to help encourage geothermal exploration, we've provided this atlas for more detailed information."