THE Ballarat region has been identified as 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 undertook studies of underground energy over the past year across southern and north-western Victoria.A ground-breaking map was released yesterday of available reserves to attract investment in geothermal energy production.Geoscience Victoria geologist David Taylor said studies of underground water tables in the Ballarat area revealed there were between 100 and 120 heat flow units, which was almost double that of the average heat flow.He said the heat was coming from a mantle hotspot. The mantle is the next layer of the earth after the crust, which is 40 kilometres down."That's the highest the number ever gets in the real world. It's higher than that of a volcano which has erupted," Mr Taylor said.He said geologists were surprised that the map showed large parts of Victoria, including Stawell, Horsham, Mildura and Ballarat, had high heat flow values."They were as high as the heat flows in South Australia, which has a high energy flow and known for geothermal exploration activity."Energy and Resources Minister Peter Batchelor said the new heat flow map highlighted Victoria's geothermal energy potential, with areas in the state's north and west looking promising."We need to find ways to cut carbon pollution when we make energy, and geothermal has a strong potential to play a key role in helping us do that in Victoria," Mr Batchelor said.Until now, most geothermal energy data in Victoria had been compiled from temperature data collected during previous petroleum drilling."Heat flow mapping is a more precise process for understanding geothermal energy, and will help government and industry make investment decisions," Mr Batchelor said.