Hot dry rock geothermal energy Hot dry rock geothermal energy Hot dry rock (HDR) is an abundant source of geothermal energy available for use. A vast store of thermal energy is contained within hot - but essentially dry - impervious crystalline basement rocks found almost everywhere deep beneath the earth’s surface. A concept for the extraction of useful amounts of geothermal energy from HDR originated at the Los Alamos National Laboratory in 1970, and Laboratory researchers were awarded a U.S. patent covering it. Although often confused with the relatively limited hydrothermal resource already commercialized to a large extent, HDR geothermal energy is very different. Whereas
Note from the Underground (Buffy comic) return Sunnydale to its natural state. Buffy rescues Xander and Dawn from The Scourge. Buffy must fight for her friends' and family's lives, and also for the right to live her own life, Faith and Angel help. "Buffy" comics such as this one are not usually considered by fans as canonical. However, unlike fan fiction, overviews summarizing their story, written early in the writing process, were approved by both Fox and Joss Whedon (or his office), and the books were therefore later published as officially Buffy merchandise. Note from the Underground (Buffy comic) "Note from the Underground" is a story