SolarPanelCalc: Solar Output

SolarPanelCalc estimates what a solar panel system will produce and save, and how big a system you need to cover your electricity use.

• Estimate Output: enter system size in kW, peak sun hours and efficiency to see daily, monthly and yearly kWh.
• Add your electricity rate and installed cost to see monthly and yearly savings and the payback period.
• Size System: start from your monthly kWh use and bill offset to get the required kW, number of panels and roof area.
• Set your own panel wattage and panel area in square meters.
• Use any currency symbol for rates and savings.
• Save scenarios with notes, reload them later, and share a short result summary.
• Itemized losses: break efficiency into ten standard loss categories (soiling, shading, wiring, availability and more) with typical default values, plus temperature and inverter, and see what remains after each step.
• 25-year cash flow: with an installed cost, project output decline, rising electricity rates, upkeep and a discount rate to see net present value, payback and 25-year net cash, with a year-by-year chart and table you can share.
• String Match: enter panel and inverter datasheet values and your coldest and hottest temperatures to get the modules-per-string range, strings per MPPT input, DC/AC ratio and four pass/fail voltage and current checks.