Solar PV System Sizing Calculation Excel Template

Solar PV system sizing is a critical early-stage engineering task that ensures the designed system reliably meets energy demand while optimizing cost, space, and performance. The Excel template operationalizes this process by guiding users through sequential inputs—such as daily energy consumption (kWh/day), peak sun hours (PSH) at the location, module specifications (e.g., wattage, efficiency), system voltage, and derating factors (e.g., temperature, soiling, wiring losses). It applies energy balance logic: the PV array must generate sufficient DC energy to cover AC loads after accounting for inverter efficiency, battery round-trip efficiency (in off-grid cases), and all cumulative losses (typically 10–25%). Advanced templates may include sensitivity analysis, monthly yield estimation using NREL’s NSRDB or PVWatts-derived PSH, battery depth-of-discharge (DoD) constraints, and payback period estimation. These tools bridge theoretical solar energy principles with real-world implementation constraints, making them indispensable for consultants, EPC firms, educators, and DIY solar adopters seeking rapid yet technically sound preliminary designs.