Solar Calc: Panels & Battery

Work out how many solar panels and how much battery you need, with every assumption in plain sight. Two modes in one app: • Home on the grid: from your monthly kWh to panels, yearly production, savings and payback. • Off-grid (RV, cabin, boat): list your appliances and get daily energy, panels, battery in Wh and Ah, charge controller amps and inverter size. What makes it different: • System losses broken down into the same categories NREL's PVWatts uses (soiling, shading, mismatch, wiring and more). Edit any of them. • Battery chemistry, depth of discharge and days of autonomy are explicit. • No made-up sunshine map: you enter your peak sun hours, and the app tells you where to look them up. • Share a plain-text summary with your installer. • No account needed. Your systems are saved on your device. Works offline. These are planning estimates, not an electrical design. Peak sun hours, tariffs and costs are yours to set. Always have a qualified installer check the final system and local code. PVWatts is a product of the U.S. National Renewable Energy Laboratory (NREL). Solar Calc is not affiliated with or endorsed by NREL.