| Abstract: | This paper traces the historical development of the energy infrastructure of cities. As a result of 150 years of this infrastructure mainly comprises electricity, gas, and, sometimes, district heating. This paper describes basic characteristics of underground storage systems applicable within city limits: gas storage, compressed air energy storage, and thermal storage. Finally, the paper describes a central storage facility for all energy forms that has the potential to provide much of the flexibility required for optimal city energy management. |
