Greenearth Energy, Hot Rock Ltd and Granite Power told a gathering of investors, stockbrokers, power industry leaders and government representatives that geothermal energy - when developed to its full potential - is expected to power base load electricity generators, reducing Victoria's reliance on highly polluting brown coal.

"We all know that any reduction of pollution will benefit our environment and existing industries, so I would strongly suggest that companies investigate energy innovation by negotiating joint ventures directly with us to unlock an enormous latent power and reduce the reliance on brown coal," Greenearth Energy director Rob Annells.

Annells said while the government should maintain its watching brief from the Geothermal Energy Resources Act 2005 to guide the development of the geothermal industry in Victoria, there had been little meaningful support from Industry looking to share the risks and rewards of developing geothermal energy solutions.

He added that Greenearth had already discovered hot water at a depth of just 2100m in Gippsland and had major markets (the national electricity grid and Melbourne) at its doorstep.

"Individual companies will recognise this fact - those seeking geothermal energy solutions will share the benefits of lowered electricity costs and reduced pollution emissions," Ansell said.

"Unlike other sustainable energy sources, geothermal energy runs night and day, long term and overseas experience confirms that geothermal has the capacity to deliver base load power into the existing grid."

He also noted the Washington-based Centre for Global Development had said Australia produced more than 10 tonnes of CO2 from coal fired power stations per person, the seventh worst in the world.

"So, I believe that relatively emission free geothermal technology must be adopted and supported by government, industry and the people of Victoria." he added.

Meanwhile, Hot Rock managing director Mark Elliott said the company's exploration for geothermal energy in deep aquifers contained in the Otway Basin in southwest Victoria had already yielded four discoveries interpreted from oil and gas wells within its permits.

"These temperatures and depths, using binary cycle power plants as used in other geothermal developments around the world, are potentially commercially attractive," he said.

"Therefore, we are fast tracking our exploration program to an appraisal production testing stage and plan to be drilling our first production test well by early 2009 and installing a one megawatt pilot plant by the end of 2009 to complete the "proof of concept" stage of development."

He said once the pilot plant has run successfully, the company plans to develop its geothermal resources that may be as large as 1750MW, adding it hoped to attract new industries that can use the spent hot fluid for heating in their processes.

Granite Power managing director Stephen de Belle was also upbeat about the cost of developing its geothermal target south of Warragul that could support a number of 250MW base load power stations.

He said that respected international and domestic experts had forecast the cost of power from its target would be about the same as for coal fired base load generation.

"It's not simply a ‘green game, geothermal electricity generation must be seen as an attractive investment opportunity if it is to succeed," de Belle said.

"Granite Power's analysis of its Victorian project suggests it should be appropriately attractive. In this context, we hope and expect that investors and government will support the geothermal industry's various development efforts."