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
Gilsland Spa Gilsland Spa Gilsland Spa is the present-day name of a hotel at Gilsland, Cumbria, England. It is named from the sulphurous spring which issues from a cliff below the hotel. The original hotel was called The Shaws, from an Old English word meaning a small woodland, and was built in the 1760s, although the site and its surrounding farmland have been known by this name since at least 1603. Lord William Howard's map of the Barony of Gilsland of this date shows two buildings near the site of the hotel labelled "Two tenements called the Shaws". Very little is known