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Both calculators run independently β€” change the inputs on either side to compare results.

Solar Energy

Solar Battery Size Calculator

Calculate required battery capacity (kWh) to back up a home for a chosen number of days at a given daily energy usage and battery depth-of-discharge limit. Use it when sizing storage for solar self-consumption, grid-outage backup, or off-grid systems.

Fill in the required fields to see your result.
Solar Energy

Solar Payback Period Calculator

Calculate how many years a solar PV system takes to pay back its net upfront cost through annual electricity bill savings. Use it as the primary financial test when evaluating whether to install solar.

Fill in the required fields to see your result.

Key differences

Solar Battery Size CalculatorSolar Payback Period Calculator
CategorySolar EnergySolar Energy
Inputs required33
ResultRequired Battery Capacity (kWh)Payback Period (years)
What it doesCalculate required battery capacity (kWh) to back up a home for a chosen number of days at a given daily energy usage and battery depth-of-discharge limit. Use it when sizing storage for solar self-consumption, grid-outage backup, or off-grid systems.Calculate how many years a solar PV system takes to pay back its net upfront cost through annual electricity bill savings. Use it as the primary financial test when evaluating whether to install solar.