Photovoltaic array PV module

A PV module is the basic power-generating unit made of solar cells, while a PV array is a complete assembly of multiple modules or strings designed to produce electricity at the scale needed for a system.

PV Module

A photovoltaic (PV) module is the fundamental building block of a solar power system. It consists of multiple solar cells encapsulated between protective layers such as glass, EVA, and a backsheet, which convert sunlight directly into direct current (DC) electricity . Typical residential modules contain 60–72 cells and produce 350–480 watts under standard test conditions (1000 W/m² irradiance, 25°C cell temperature), . Modules are designed to be weatherproof and durable, with lifespans of 20–30 years and warranties often guaranteeing a high percentage of rated power output over 20 years . Modern modules use technologies like monocrystalline, TOPCon, HJT/SHJ, and back-contact designs to improve efficiency and long-term performance .

PV String

A PV string is formed by connecting several PV modules in series, which increases the total DC voltage to match the input requirements of an inverter. Modules in a string are usually matched for electrical characteristics to maximize system performance . Multiple strings can then be connected in parallel to increase the total current, allowing the system to scale efficiently.

PV Array

A photovoltaic array is the complete DC power-generating unit, consisting of multiple modules or strings mounted on a support structure and electrically connected to meet specific energy needs . Arrays are designed considering layout, orientation, and inverter compatibility to ensure high efficiency and reliability. The array's voltage and current characteristics are determined by the configuration of modules and strings, which must align with the inverter specifications . Arrays can range from small residential rooftop systems to utility-scale solar farms.

Performance and Ratings

PV modules and arrays are rated by their maximum DC power output (watts) under Standard Test Conditions (STC), which include 25°C cell temperature, 1000 W/m² irradiance, and Air Mass 1.5 spectral distribution . Actual field performance is typically 85–90% of STC ratings due to environmental factors. The I-V characteristics of modules define short-circuit current and open-circuit voltage, which are critical for system design and fault protection .

Summary

• PV Cell: Converts sunlight to electricity.
• PV Module: Encapsulated cells forming a weatherproof unit.
• PV String: Series-connected modules to increase voltage.
• PV Array: Complete assembly of modules/strings generating the required DC power. This hierarchical structure allows PV systems to be scalable, adaptable, and efficient for various applications, from residential rooftops to large-scale solar farms .