Hot dry rock geothermal energy
（重定向自Hot dry rock）
Hot dry rock (HDR) is by far the most abundant source of geothermal energy available to mankind. A vast store of thermal energy is contained in the 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 was so groundbreaking that Laboratory researchers were awarded a U.S. patent covering it.