Geothermal heating a total capacity of 15 GW extracted 88 PJ of heat energy for space heating. Global ground-source heat pump capacity is growing by 10% annually. Hot springs have been used for bathing at least since Paleolithic times. The oldest known spa is a stone pool on China's Mount Li built in the Qin dynasty in the 3rd century BC, at the same site where the Huaqing Chi palace was later built. Geothermal energy supplied channeled district heating for baths and houses in Pompeii around 0 AD. In the first century AD, Romans conquered Aquae Sulis in England and used the
Aquae Sulis cuamiun ai" "The affixed – Deuina, Deieda, Andagin, (and) Uindiorix – I have bound" An alternative translation based on a much better knowledge of the Celtic languages is the following: "May I, Windiorix for/at Cuamena defeat (alt. "summon to justice") the worthless woman, oh divine Deieda." (Alt. "Divine Deiada, may I, Windiorix, bring to justice/defeat (in court) the woman at Cuamena".) This is a superior, though still uncertain, translation in that it takes into account the nominal cases of the nouns: "Windiorix" (alt. "Windorix") - nominative masculine (subject), lit. "fair-headed" ("windo") "king" ("rix"); "Dewina Deieda" - nominative/vocative feminine "divine Deieda"