Geothermal energy is the natural heat of the earth and presents a potential commercially viable and sustainable solution to problems of pollution, greenhouse gas emissions and rising fuel prices. The US Department of Energy has estimated that global geothermal energy resources aggregate to approximately 50,000 times the energy of all the world’s known reserves of oil and gas.

Of the four different types of geothermal energy resources (geo-pressured, magma, hydrothermal and hot dry rock) only hydrothermal is currently being used commercially. Hydrothermal energy is employed in at least 70 countries in direct use applications for space heating, greenhouses or aquaculture or to produce electricity.

Hot dry rock (“HDR”) also known as “Hot Fractured Rock”, "Hot Wet Rock" or “Enhanced Geothermal Systems” or "EGS", is heat in hot rocks buried deep in the earth that does not have a natural system of permeable water filled fractures. The rocks are hot due to heat generated at depth which is trapped by the insulating effect of overlying rocks. The extraction of heat from hot rocks is achieved by pumping cool water into the rocks at depth, and subsequently withdrawing it at a much higher temperature after it has flowed under pressure through fractures in the hot rocks.