Grid-connected photovoltaic power system Solar energy gathered by photovoltaic solar panels, intended for delivery to a power grid, must be conditioned, or processed for use, by a grid-connected inverter. Fundamentally, an inverter changes the DC input voltage from the PV to AC voltage for the grid. This inverter sits between the solar array and the grid, draws energy from each, and may be a large stand-alone unit or may be a collection of small inverters, each physically attached to individual solar panels. See AC Module. The inverter must monitor grid voltage, waveform, and frequency. One reason for monitoring is if the grid is dead
Localization of a module ideals) then the localization is denoted "M" instead of ("R"\"p")"M". The support of the module "M" is the set of prime ideals "p" such that "M" ≠ 0. Viewing "M" as a function from the spectrum of "R" to "R"-modules, mapping this corresponds to the support of a function. Localization of a module at primes also reflects the "local properties" of the module. In particular, there are many cases where the more general situation can be reduced to a statement about localized modules. The reduction is because an "R"-module "M" is trivial if and only if all its localizations at