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
Battle of Aquae Sextiae three hundred of their married women were to be handed over to the Romans. When the Teuton matrons heard of this stipulation they first begged the consul that they might be set apart to minister in the temples of Ceres and Venus; and then when they failed to obtain their request and were removed by the lictors, they slew their little children and next morning were all found dead in each other's arms having strangled themselves in the night. Battle of Aquae Sextiae The Battle of Aquae Sextiae (Aix-en-Provence) took place in 102 BC. After a string of Roman defeats