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
Length of a module precisely the simple modules. For every finite-dimensional vector space (viewed as a module over the base field), the length and the dimension coincide. The length of the cyclic group Z/"n"Z (viewed as a module over the integers Z) is equal to the number of prime factors of "n", with multiple prime factors counted multiple times. A module "M" has finite length if and only if it is both Artinian and Noetherian. (cf. Hopkins' theorem) If "M" has finite length and "N" is a submodule of "M", then "N" has finite length as well, and we have length("N") ≤ length("M"). Furthermore,