jü( )l, n: A unit of energy measurement equal to a watt-second.
Union Electric Co. and the Electric Power Research Institute have teamed on a low-cost geothermal project that uses water from an abandoned lead mine to heat and cool the new Park City, MO, town hall. The mine's 70 billion gallons of water remain at 58°F year-round. In winter, well water goes through a heat exchanger, transferring heat from the mine water to a heat pump system, which converts the heat to warm air. In summer, the process is reversed.