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
Roman Catholic Diocese of Acqui Roman Catholic Diocese of Acqui The Roman Catholic Diocese of Acqui () straddles the (civil) regions of Piedmont and Liguria, in northwest Italy. The ancient Roman name of the place was "Aquae Statiellae", which was sometimes confused with "Aquae Sentiae" (Aix-en-Provence), and "Aquae Augustae" (Dax), where there were also bishops. Acqui had always been subordinate to the Province of Milan, down until 1817, when Pope Pius VII assigned it to the Province of Turin. As a suffragan of the Archdiocese of Turin, it falls within the ecclesiastical region of Piedmont. It is probable that the diocese of Acqui was established