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
Echoes from the Underground Echoes from the Underground Echoes from the Underground is the sixth studio album from the band Vertical Horizon, released on October 8, 2013. "Broken Over You" was released as the lead single. Rush drummer Neil Peart played the drums on two songs on the album, including "Instamatic". After the band's 2009 album, "Burning the Days", band co-founder Keith Kane left the band shortly after in 2010, to pursue solo projects. The band's other co-founder, and frontman Matt Scannell turned to crowdfunding to financially support the creation of the album. Supporters who put down money ahead of time were allowed first