Design and evaluation of an advanced adiabatic compressed air energy storage system at the Michigan-Utah Mine

Compressed air energy storage (CAES) is considered a viable option for matching intermittent sustainable energy and the production of peak electrical demand. Economic advantages of CAES may be realized by storing inexpensive off-peak power at night and on weekends for use during peak hours when electricity prices are high (arbitrage). Traditional CAES facilities use a natural gas burner to heat the air entering the expander. This study examines the feasibility of replacing the natural gas burner with heat exchangers that collect waste heat from the compression cycle and designing an advanced adiabatic compressed air energy storage process that eliminates the need for combustion.;This feasibility study will include the development of a software package called CAES Simulator using the commercial program Matlab(c), to model thermodynamic properties of a CAES system. The computational model uses a time series iterative forward differencing method to simulate the operation of a CAES plant. Users enter boundary conditions pertaining to ambient air properties and equipment limitations and CAES Simulator calculates thermodynamic properties of the system such as overall efficiency and thermal loads. CAES Simulator is equipped to consider the psychometric properties of air and the effects of humidity changes caused by condensation during cooling. The computational model was validated experimentally by comparing trended data of the compression cycle of a 280 HP Gardener-Denver tandem horizontal two stage compressor to computational results.;CAES Simulator was used to identify the effects of changing ambient air properties on the overall efficiency of an AA-CAES system at the Michigan-Utah Mine in Cottonwood Canyon, Utah. Summit County's geological conditions are rich with hard rock, salt formations and aquifers making the area's 1200 miles of abandoned mine a prime candidate for this application. It was found that rises in ambient humidity and temperature increased the operating temperatures and heat recovery requirements of an AA-CAES plant. Utah's cold dry climate allows machinery to operate at lower temperature making the Michigan-Utah Mine an ideal location for an AA-CAES. This study demonstrated that an AA-CAES plant's efficiency is dependent on equipment constants but an efficiency of 75% is obtainable given the right operating conditions.