Hot Rock Limited's Otway Basin geothermal resources in Victoria are large. They are located in the middle of a large population base of 5 million people with a major 500 kV electrical transmission system nearby. Hot Rock has already completed the largest MT geophysical survey for geothermal to date in Australia over a part of this resource. The existing data shows potential to generate 35% of the state of Victoria's electricity needs.

Hot Rock Limited holds five GEP's (Geothermal Exploration Permits) in Victoria. These total 27,521 km² and were granted in two releases in May 2007 and November 2008 for 5 years:

• They are located near the western Victorian coastline, stretching 270 km from the South Australian border to Lorne.
• They lie over a geological feature called the Otway Basin. This was heavily explored for oil and gas in the past thirty years which provides a large amount of existing exploration data for Hot Rock to evaluate.

Hot Rock chose this area for geothermal exploration because it has the most promise for relatively shallow geothermal resources at commercial temperatures. Importantly, the GEP's are close to a major high voltage transmission grid and other infrastructure. Hot Rock's review of the existing data has confirmed the excellent potential of these GEP's.

The type of resource is called "sedimentary geothermal". It is an aquifer, like the Great Artesian Basin but with temperatures boosted by thinning crust related to rifting, recent volcanism and underlying hot granites.

In some areas, there are temperatures of over 140^oC at relatively shallow depths of 3,000 metres to 3,500 meters.

An independent review by consultants SKM showed that there is scope for generation of up to 1,750 MWe (approximately 35% of Victoria's base load electricity needs) from these four GEP's.

Hot Rock is now moving ahead with project development. Hot Rock carried out the largest ever MT geophysical survey for geothermal in Australia from May to July of 2008 over a selected area at Koroit in GEP8.

Figure 1 - Location map of Hot Rock's permits

Figure 2 - Hot Rock carried out the largest MT survey ever for geothermal energy in Australia in the winter of 2008

Figure 3 - Transmission lines are nearby