What voltage is required for a PV system? This standard applies to roof-mounted,ground-mounted,pole-mounted,or integrated-mounted modules used in a PV system with a voltage of 1000 voltsor less. The National Electrical Code applies from an installation standpoint. The exact voltage depends on panel type, cell count, temperature, and sunlight intensity. It could be anywhere between 21. The voltage that is. . Plane of Array Irradiance, the sum of direct, diffuse, and ground-reflected irradiance incident upon an inclined surface parallel to the plane of the modules in the photovoltaic array, also known as POA Irradiance and expressed in units of W/m2. Performance Ratio based on measured production. . IEC has developed a series of standards specifically for solar PV systems, addressing various aspects such as design, installation, operation, and maintenance. These standards include compliance with industry regulations such as UL. .