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The Status and Future of Flywheel Energy Storage

Pullen, K. R. ORCID: 0000-0001-8501-9226 (2019). The Status and Future of Flywheel Energy Storage. Joule, doi: 10.1016/j.joule.2019.04.006

Abstract

Flywheels, one of the earliest forms of energy storage, could play a significant role in the transformation of the electrical power system into one which is fully sustainable yet low cost. This article describes the major components that make up a flywheel configured for electrical storage and why current commercially available designs of steel and composite rotor families coexist. In the process, design drivers, based on fundamentals are explained in a clear and simple manner inclusive of approaches to safety. The robust characteristics of flywheels deem them highly suitable for applications requiring fast response and high daily cycles, a need that is growing as grid inertia reduces. Lithium Ion batteries are currently the technology of choice for fast response but suffer from limited cycle and calendar life. This can be mitigated by having sufficient energy capacity to limit depth of discharge during short duration cycles whilst using this capacity to earn revenue for provision of other services. Now, as other mechanical, thermal to electric and renewable fuel based storage technologies develop, these will provide storage at a lower cost, greater duration and in a more sustainable way than Lithium Ion. However, the need for fast response storage will remain and steel flywheels are well placed to provide this given potential for low power cost and their sustainability credentials. In order to obtain cost estimates for flywheels in volume production, the cost of the power and storage elements were separated out with costs for each based on similar technologies in volume production. These indicate significantly lower costs than given for current commercially available flywheels, none of which are in volume production relative to Lithium Ion. Finally, some areas of research with potential to improve performance are described but, to be worthwhile, these developments must not lead to increased costs.

Publication Type: Article
Publisher Keywords: © Elsevier 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
Subjects: T Technology > TJ Mechanical engineering and machinery
Departments: School of Mathematics, Computer Science & Engineering > Engineering > Mechanical Engineering & Aeronautics
URI: http://openaccess.city.ac.uk/id/eprint/22226
[img] Text - Accepted Version
This document is not freely accessible until 2 May 2020 due to copyright restrictions.
Available under License Creative Commons Attribution Non-commercial No Derivatives.

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