Photovoltaic system to microgeneration and photovoltaic systems, and the US UL4703 standard, in subject 4703 ""Photovoltaic Wire"". A solar tracking system tilts a solar panel throughout the day. Depending on the type of tracking system, the panel is either aimed directly at the sun or the brightest area of a partly clouded sky. Trackers greatly enhance early morning and late afternoon performance, increasing the total amount of power produced by a system by about 20–25% for a single axis tracker and about 30% or more for a dual axis tracker, depending on latitude. Trackers are effective in regions that receive a large
Injective module Injective module In mathematics, especially in the area of abstract algebra known as module theory, an injective module is a module "Q" that shares certain desirable properties with the Z-module Q of all rational numbers. Specifically, if "Q" is a submodule of some other module, then it is already a direct summand of that module; also, given a submodule of a module "Y", then any module homomorphism from this submodule to "Q" can be extended to a homomorphism from all of "Y" to "Q". This concept is dual to that of projective modules. Injective modules were introduced in and are