CurveACFuse is a handy toolkit for solar and AC/DC and checks. It shows how many energy units you lose during planned or unplanned downtime using event time and system size. It checks I-V curves and tells you if strings look right after STC fixes, catching shade, mismatch, or wiring issues early. It models voltage drop across many cable segments and estimates power loss, so you can choose better routes or wire sizes. It helps you pick cable gauges by load and site limits for safe, low-cost builds. It sizes strings against cold VOC and hot VMP to fit the inverter window, and flags both over-voltage and under-voltage risks. It suggests fuses and breakers from real run current and code factors that line up with upstream gear. It also plans combiner loading and trends insulation resistance over time to spot moisture or aging before it hurts output.