“The capacity of solar photovoltaic generation stations can be expressed in more than one
way. Because there has historically been some inconsistency in the norms that have been
used to specify a capacity rating, this paper assesses the different approaches, considers
the alternatives and recommends nomenclature that should be preferred. Wiki-Solar will
seek to apply this standard across its website and publications.
The two main alternatives that have been used in the past have been MWP, the rated DC
capacity of the solar array under solar Standard Test Conditions, and MWAC, the output it is
designed to deliver to the grid under these conditions. Often the suffixes have been excluded
and the designation MW has been used for either measure.”
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Wolfe, Philip. Wiki Solar 13 July 2013.