Role of the heat storage well in future U. S. energy systems

The Heat Storage Well system concept is found to have the potential to decrease U.S. energy consumption 10 to 15 percent while substantially reducing water and air pollution. Energy to be conserved is principally that now wasted in generating electricity and in burning fossil fuels for space heating. Results of a study of technical, economic, institutional, environmental, and legal aspects of implementation are reported. Joint production of power and heat with gas turbines and at large central coal-fired plants is analyzed. Costs of joint production, with heat storage, are compared to separate costs of generating heat on-site and purchasing electricity. Water heated as electricity is generated is injected via Heat Storage Wells into aquifers where it is stored to be withdrawn as needed to meet seasonal heat loads. About 75 percent heat recovery is expected. Producing heat and power jointly with a gas turbine and heat-recovery system with heat storage is compared to separate-product systems and found to cost 25 percent less and to consume 35 percent less fuel. Electricity and heat can be produced jointly and transmitted as far as 125 miles (200 km) from a central plant at a cost about equal to separate-product costs, with an energy saving of 16 percent. Regulatory institutions governing utilities do not yet regard energy conservation as an important consideration but practices are changing. Municipal utilities, close to community needs such as converting from oil and gas to coal, and with ability to finance more easily than investor-owned utilities by bonds and taxation, are found to be those most likely to first implement the Heat Storage Well system concept.