A 120-watt monocrystalline solar system typically consists of several key components:Solar Panels: Monocrystalline solar panels are made from single-crystal silicon, which gives them a uniform appearance and high efficiency. These panels are known for their sleek black appearance and higher efficiency compared to polycrystalline panels. A 120-watt monocrystalline panel would typically generate around 120 watts of power under standard test conditions (STC).Charge Controller: A charge controller regulates the flow of electricity from the solar panels to the batteries. It prevents overcharging and ensures efficient charging of the battery bank. For a 120-watt system, a charge controller with a capacity of at least 10-20 amps would be suitable, depending on the battery bank size and configuration.Battery Bank: The battery bank stores the energy generated by the solar panels for later use, typically during periods when sunlight is not available (such as at night or during cloudy weather). The size of the battery bank depends on the energy requirements and the expected duration of backup power needed.Inverter (if applicable): If the system is intended to power AC appliances or devices, an inverter is required to convert the DC power generated by the solar panels and stored in the batteries into usable AC power. The size of the inverter would depend on the maximum power demand of the appliances.Mounting Hardware and Wiring: The solar panels need to be securely mounted on a suitable structure, such as a roof or ground mount. Additionally, appropriate wiring is needed to connect the solar panels to the charge controller, battery bank, and inverter (if applicable).Accessories: Various accessories such as junction boxes, connectors, and fuses are necessary to ensure the safe and efficient operation of the solar system.A 120-watt monocrystalline solar system can be suitable for powering small off-grid applications such as RVs, boats, cabins, or small remote electronic devices. It can also serve as a component of a larger solar power system for residential or commercial use, providing supplemental power or serving specific energy needs.