A measure of the flow of current (in amperes) over one hour when the rate of flow is one ampere: An ampere-hour is equal to 3600 coulombs (standard international unit of electric charge).

The ampere-houris used to measure battery capacity.

The equivalent number of hours per day when solar irradiance averages 1,000 w/m2; for example, six peak sun hours means that the energy received during total daylight hours equals the energy that would have been received had the irradiance for six hours been 1,000 w/m2.