To build a complete off-grid solar system, you need a bifacial solar panel, a charge controller to regulate power flow, and a battery to store energy. Additionally, you'll need adapter kit cables to connect the solar panels and charge controller, as well as tray cables to link the charge controller to a deep-cycle battery.

An on-grid solar system is connected to the utility grid, allowing you to draw power from the grid and send excess energy back. In contrast, an off-grid solar system is completely independent, storing generated power in batteries for later use. Off-grid systems ensure uninterrupted power and are not affected by grid outages.

A bifacial solar panel may generate less power due to indirect sunlight, excessive heat, cloudy weather, or dirt buildup on the glass surface. These factors reduce energy absorption and overall efficiency.

Solar panels can be wired in series or parallel, depending on your system voltage and current requirements. Series wiring raises system voltage, ideal for high-voltage setups, while parallel wiring boosts current for battery-based systems. In contrast, a parallel connection increases the system’s current while maintaining the same voltage, making it better suited for battery-based systems that require higher amperage. To achieve the best power output and system efficiency, a combination of series and parallel connections may be used based on your solar energy storage and inverter requirements.

The best way to gauge how many solar panels you need, is to understand and define the power load needed from this system. Power is measured in Watts, and capacity is commonly measured in Watt-hours (multiplying power output in watts by the required number of hours of operation multiplied by a safety factor of 1.5-2). Therefore, it is wise to size your battery bank first based on the minimum required capacity, and accordingly decide how many panels or how much power input is needed.

When you open the product page, you will see a title like "xxx Watt 24 Volt Monocrystalline Solar Panel". The "24V" here does not refer to the voltage of this solar panel (VOC or VMP), but to the fact that one xxxW solar panel is suitable for 24V system (i.e. a 24V battery)，no need for additional series and parallel connections.Therefore, these are two completely different values with different meanings.