Photovoltaic system and is typically less useful than a calculation of return on investment. While it is typically calculated to be between 10 and 20 years, the financial payback period can be far shorter with incentives. Due to the low voltage of an individual solar cell (typically ca. 0.5V), several cells are wired "(also see copper used in PV systems)" in series in the manufacture of a "laminate". The laminate is assembled into a protective weatherproof enclosure, thus making a photovoltaic module or solar panel. Modules may then be strung together into a photovoltaic array. In 2012, solar panels available for consumers
Generating set of a module ideal "m" and residue field "k" and "M" finitely generated module. Then Nakayama's lemma says that "M" has a minimal generating set whose cardinality is formula_3. If "M" is flat, then this minimal generating set is linearly independent (so "M" is free). See also: minimal resolution. A more refined information is obtained if one considers the relations between the generators; cf. free presentation of a module. Generating set of a module In algebra, a generating set "G" of a module "M" over a ring "R" is a subset of "M" such that the smallest submodule of "M" containing "G" is