Rooftop photovoltaic power station Rooftop photovoltaic power station A rooftop photovoltaic power station, or rooftop PV system, is a photovoltaic system that has its electricity-generating solar panels mounted on the rooftop of a residential or commercial building or structure. The various components of such a system include photovoltaic modules, mounting systems, cables, solar inverters and other electrical accessories. Rooftop mounted systems are small compared to ground-mounted photovoltaic power stations with capacities in the megawatt range. Rooftop PV systems on residential buildings typically feature a capacity of about 5 to 20 kilowatts (kW), while those mounted on commercial buildings often reach 100 kilowatts or more.
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