When connecting 10 panels in series, the total voltage becomes: Higher-efficiency 24V panels? That's 240V! Here's where it gets juicy. Your 12V panel isn't really 12V - that's just its "nominal" rating. Actual open-circuit voltage (V OC) might be 18-22V per panel. In this post, we'll learn how to size and connect solar panels step-by-step, arranging them in the right series–parallel combination and ensuring they operate safely and efficiently within the inverter's MPPT window — the heart of every well-designed solar system. How does a Grid-tied solar power. Definition: This calculator determines the total voltage, current, and power output of solar panels connected in series and parallel configurations. Purpose: It helps solar installers and DIY enthusiasts properly design their solar array to match their system requirements. For example, let's say you have 3 identical solar panels. But many times, we need power in a range from kW to MW. A String of PV Modules When N-number of PV modules are connected in series.