Energy in South Australia and trap in the deeper heat. Due to the low permeability of granite, the hot rocks must undergo hydraulic fracturing and be stimulated to allow a flow of water through the system to produce energy. This heat is slowly conducted to shallower rocks near the surface. Petratherm propose developing the geothermal energy in the more permeable sedimentary rocks that overlay the hot granite, a process called Heat Exchange Within Insulator (HEWI). While somewhat cooler, in many cases they do not require hydraulic fracturing. It is estimated that one percent of geothermal energy shallower than five kilometres below the earth's surface
Hot Water Beach tide, it is possible to dig into the sand allowing hot water to escape to the surface forming a hot water pool. The water, with a temperature as hot as 64 °C (147 °F), filters up from two underground fissures located close to each other. These natural springs can be found on the beach opposite the off-shore rocks. Visitors often dig large holes and relax and soak in the thermal water. Many visitors bring a spade and bucket with them. Spades can also be hired from the nearby surf shop. Care needs to be exercised as the location of the