Flywheel energy storage systems are increasingly being considered as a promising alternative to electro-chemical batteries for short-duration utility applications. There is a scarcity of research that evaluates the techno-economic performance of flywheels for large-scale applications. Evaluating the capital cost, levelized cost of storage, and scale factor is crucial to make an informed decision in future development and deployment of the technology. This study, therefore, focuses on developing a bottom-up techno-economic model to design system components and to evaluate the total investment cost and levelized cost of storage of flywheels with a capacity of 20 MW/5 MWh for frequency regulation. Two rotor configurations were considered: composite rotor flywheel and steel rotor flywheel. The total investment costs of the composite rotor and steel rotor flywheel storage systems are $25.88 million and $18.28 million, respectively. The corresponding levelized costs of storage are $189.94/MWh and $146.41/MWh. The model results are highly sensitive to the cost of the rotor material, discount rate, factor of safety, number of cycles per year, and tensile strength of the rotor material. The ranges obtained in the uncertainty analysis for the levelized cost of storage are $122.08-$253.52/MWh and $108.63-$187.64/MWh for the composite rotor and steel rotor flywheel storage systems, respectively.

飞轮储能系统越来越被认为是用于短期公用事业应用的电化学电池的有前途的替代品。很少有研究评估飞轮在大规模应用中的技术经济性能。评估资本成本、平准化存储成本和比例因子对于在未来的技术开发和部署中做出明智的决策至关重要。因此，本研究的重点是开发一种自下而上的技术经济模型来设计系统组件，并评估总投资成本和调频容量为 20 MW/5 MWh 的飞轮存储的平准化成本。考虑了两种转子配置：复合转子飞轮和钢转子飞轮。复合转子和钢转子飞轮存储系统的总投资成本分别为 2588 万美元和 1828 万美元。相应的平准化存储成本为 189.94 美元/MWh 和 146.41 美元/MWh。模型结果对转子材料的成本、折扣率、安全系数、每年的循环次数和转子材料的抗拉强度高度敏感。对于复合转子和钢转子飞轮储能系统，在不确定性分析中获得的平准化储能成本范围分别为 122.08-253.52 美元/MWh 和 108.63-187.64 美元/MWh。安全系数、每年循环次数和转子材料的抗拉强度。对于复合转子和钢转子飞轮储能系统，在不确定性分析中获得的平准化储能成本范围分别为 122.08-253.52 美元/MWh 和 108.63-187.64 美元/MWh。安全系数、每年循环次数和转子材料的抗拉强度。对于复合转子和钢转子飞轮储能系统，在不确定性分析中获得的平准化储能成本范围分别为 122.08-253.52 美元/MWh 和 108.63-187.64 美元/MWh。