Flywheel energy storage costs for small rooftop communication base stations

Equipment cost distribution for the flywheel energy storage systems. FESSs are used for short-duration power applications. Therefore, power capital cost ($/kW) could be a useful parameter to compare the economic feasibility of energy storage systems for similar power applications.

However, almost no bottom-up research has been done, i.e., research that considers the technical parameters to size the components of a flywheel storage system, estimate cost parameters based on the design, and provide a probable distribution of the total investment cost and levelized cost of storage.

The steel rotor flywheel has a lower capital cost and levelized cost of storage. The costs of composite and steel rotor flywheels are $190 and $146/MWh, respectively. Flywheel energy storage systems are increasingly being considered as a promising alternative to electro-chemical batteries for short-duration utility applications.

Utility-scale energy storage systems for stationary applications typically have power ratings of 1 MW or more . The largest flywheel energy storage is in New York, USA by Beacon Power with a power rating of 20 MW and 15 min discharge duration .

However, the high cost of purchase and maintenance of solar batteries has been a major hindrance. Flywheel energy storage systems are suitable and economical when frequent charge and discharge cycles are required. Furthermore, flywheel batteries have high power density and a low environmental footprint.

The use of new materials and compact designs will increase the specific energy and energy density to make flywheels more competitive to batteries. Other opportunities are new applications in energy harvest, hybrid energy systems, and flywheel's secondary functionality apart from energy storage.