The discharge and subsequent charge of a battery.

The number of cycles, to a specified depth of discharge, that a cell or battery can undergo before failing to meet its specified capacity or efficiency performance criteria.

Slow movement of an element from the environment, through food webs, then back to the environment.

A material cycle in which carbon flows through an ecosystem.

A battery with large plates that can withstand many discharges to a low state-of-charge.

The ratio of active time to total time. Used to describe the operating regime of appliances or loads in photovoltaic systems.

The interdependent and continuous circulation of water from the ocean, to the atmosphere, to the land, and back to the ocean.

The estimated cost of owning and operating a photovoltaic system for the period of its useful life.

A period of nineteen years after which the phases of the moon reoccur on the same days of the year.

A series of four or five eclipses also occurs on the same dates after this interval.

A battery with small plates that cannot withstand many discharges to a low state-of-charge.