One million watts of alternating current. When the array is operating at STC, its MWAC is the MWP x the performance ratio.
Ratio of actual output of a solar generating system to the rated peak output of its solar array under prevailing solar radiation conditions [ref chapter 14 of the book]
Output figures and energy ratings
Energy produced by a power plant delivering one MW for one hour. Almost always rated in terms of AC for utility-scale systems
Megawatt hours per annum
Number of megawatt hours delivered by a generating station over the course of a year (a good comparative measure for solar systems, because seasonal output can vary substantially, but year-to-year variations are relatively small)
Load factor or Capacity utilisation
Ratio of the electrical energy produced by a generating unit relative to the energy that could have been produced at continuous full-power operation during the same period (typically 12% to 28% for PV plant, depending on location)
Number of MWh per annum for each MWP of rated capacity (gives the output and revenue potential of a project). Effectively = load factor ÷ performance ratio.
% or h/y
Percentage of the time that electricity generating plant is available to produce electricity (free from downtime). Not to be confused with capacity factor
Other glossary items
There is a comprehensive and excellent glossary in the book.
Standard Test Conditions
For solar module testing, defined in international standards; insolation intensity of 1kWm-2 normal to the plane of the solar module at ambient temperature of 25°C and light spectrum equivalent to AM1.5