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
What Is the What writes: "Over the course of many years, Dave and I have collaborated to tell my story... I told [him] what I knew and what I could remember, and from that material he created this work of art." The book is typical of Eggers' style: blending non-fictional and fictional elements into a non-fiction novel or memoir. By classifying the book a novel, Eggers says, he freed himself to re-create conversations, streamline complex relationships, add relevant detail and manipulate time and space in helpful ways—all while maintaining the essential truthfulness of the storytelling. However, not all critics were impressed. Lee Siegel sees