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
On the Rocks (play) there is nothing new in this, since the "extermination of what the exterminators call inferior races is as old as history." What is new is that modern politicians since the French revolution have created a social principle of extermination, whether it be of aristocrats as in the case of France, or Jews as in Germany. This is an outgrowth of class conflict, but in the future such decisions can be made scientifically. On the Rocks (play) On the Rocks: A political Comedy (1932) is a play by George Bernard Shaw which deals with the social crisis of the Great Depression.