An Ultimate Solution to Phasing Out Fossil Fuels - Part I: Utility-Scale Underground Hot-Water Storage (Usuhws) for Power Production and Heat Supply

Abstract

This paper introduces utility-scale underground hot water storage (USUHWS) systems and evaluates their performance to enable renewable energy sources to produce dispatchable utility-scale power or supply heat with minimized interruption and impact by weather conditions. The USUHWS systems could retain the thermal energy content of the stored hot water for years so that renewable energy can be extracted and stored at any time year-round and be used whenever needed. Another major objective of this paper is to introduce hot-water power and heat internets to interconnect storage systems, power plants, energy sources, and various water and heat users to efficiently manage the demands and supplies of power, heat, and water. Also, the USUHWS can be used to collect, store, and supply fresh water for communities. For more efficient construction of USUHWS systems, tunnel boring machines (TBMs) may be employed. In combination with renewable-energy-based thermal power plants using hot water as the heat-supply fluid, the USUHWS systems could have the potential to phase out most fossil fuels used today through renewable power production and heat supplies to combat global warming.

Aan Ultimate Solution to Phasing Out Fossil Fuels – Part Ii: Air-Water Thermal Power Plants for Utility-Scale Power Production at Low Temperatures

“…Thermal power plants that could enable the use of the vast amount of thermal energy resources at low or medium temperatures to generate electricity could have a significant impact on the advancement of renewable energy. Cao (2022a) demonstrated the concept of utilityscale underground hot-water storage facilities in conjunction with thermal power plants, which could have the potential to displace more than 80% of the global fossil fuel being used today. However, economic feasibility of the storage systems is very sensitive to their temperature and pressure, and a favorable temperature range was shown to be near or slightly above 100 o C, more specifically in the low-mid temperature range between 90 to 150 o C. If the water temperature is significantly above this range, the costs of the hot-water storage system could increase exponentially.…”