In solar design, controlling line losses is essential because excessive resistive loss reduces system efficiency, lowers inverter input voltage, affects power delivery, and can lead to overheating or code violations. Then line loss is something you absolutely need to consider. In this guide, I'll walk you through how to use an online calculator that will give an estimate of line losses, and compare. By. Are you planning a DIY solar setup where your solar panels are quite a distance away from the rest of your. Line losses refer to the electrical energy lost as heat when current flows through conductors such as wires, busbars, and cables in a solar PV system. This loss is influenced by the length and thickness of the wire,as well as the amount of current flowing. PV system losses have a substantial impact on the overall efficiency and output power of solar panel arrays.