An integrated design of LNG cold energy recovery for supply demand balance using energy storage devices

Due to the fluctuation of LNG supply, the profile of power generation has a mismatch with that of power demand, which causes power shortage at the demand peak time and power overcapacity at the valley time. To address this issue, a combined system containing standalone power generation subsystem and liquid air energy storage subsystem is proposed. The energy storage subsystem stores the surplus cold energy of LNG at the valley time, and it is released as power supplement at the peak time. As a stable heat source, geothermal energy is utilized to enhance the work output. Considering the uncertainties of power supply and power demand, Gaussian distribution model is introduced. Finally, the energy storage subsystem obtains 138 kW net work output of unit mass flow of LNG, achieving at least 29% improvement compared with previous works in the literature. The stored power can reach 148 MW/day and can meet the power shortage in the boundary condition of Gaussian distribution, which is a unique work in contrast to previous studies. The combined system achieves the net present value of 326.7 million dollars at the end of span life, and 3.6 dynamic payback years. (c) 2021 Elsevier Ltd. All rights reserved.