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 formal algebraic geometry. Let "M" be a (left or right) module over some ring "R". Given a chain of submodules of "M" of the form we say that "n" is the "length" of the chain. The length of "M" is defined to be the largest length of any of its chains. If no such largest length exists, we say that "M" has infinite length. A ring "R" is said to have finite length as a ring if it has finite length as left "R" module. The zero module is the only one with length 0. Modules with length 1 are