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ENERGY TOOL · NO ACCOUNT REQUIRED

Solar and battery budget.

Estimate daily harvest from panel watts, peak sun hours and an explicit performance factor.

Panel energy goes through a compatible charge controller into battery storage and loads. Illustrative harvest is 200 watts times 4 equivalent peak-sun hours times a 0.75 performance factor, or 600 watt-hours per day.
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From sunlight to useful energyPanel energy goes through a compatible charge controller into battery storage and loads. Illustrative harvest is 200 watts times 4 equivalent peak-sun hours times a 0.75 performance factor, or 600 watt-hours per day.Reference: Victron — Wiring Unlimited

INTERACTIVE CALCULATOR

Adjust the inputs. Estimates update instantly; nothing is uploaded.

YOUR ESTIMATE

Enter measurements to see the calculation.
How it works

Estimated daily solar harvest = panel watts × peak-sun-hours × system efficiency. Reserve capacity shown uses usable 80% battery energy as a planning assumption.

Important limitation

This is not an MPPT controller selection calculator. Check panel Voc at cold temperature, Isc, controller/battery voltage and all manufacturer limits.

IF YOU WANT THE WHOLE STORY

The math is the beginning.

The secret variable is not panel wattage. It is daily watt-hours after shade, controller losses and a boat that refuses to face the sun.

Read the companion guide

PUT THE RESULT TO WORK

SmartSolar 100/30: size the array around the controller limits

The SmartSolar 100/30 is a specific controller to consider once daily consumption and mounting area are known. It is not a universal companion to any collection of panels. Shade, panel wiring and cold-weather open-circuit voltage can rule out a proposed array even when its nameplate watts look reasonable.

Read the buying guide →