Solar Panel Calculator & Home Energy Tools

Build an appliance list to estimate daily electricity use and connected load.

Estimate your solar array, continuous inverter output and battery storage together.

Plan panels, battery autonomy, reserve recharge and inverter power for an off-grid home.

Estimate the daily solar energy available for air conditioning.

Estimate pumping energy, flow and solar array capacity from water demand and head.

Calculate the solar energy and panels needed for your daily driving.

Estimate panels, battery storage and roof area from your camper's daily electricity use. The area allowance does not prove the panels fit; check the layout and allow extra energy to recharge after cloudy days.

This sizes a solar thermal water heater, not electric solar panels. Water demand and temperature rise give a first estimate; tank and pipe losses, winter backup and local installation requirements need separate checks.

Turn daily energy demand into an array rating and a whole number of panels.

Enter panel watts and quantity to estimate daily and monthly electricity output.

Estimate panel surface area and a preliminary roof-space allowance.

Get a latitude-based fixed-tilt starting point for a solar array.

Estimate electricity production from your local sun-hour assumption.

Calculate array voltage, current and power for identical modules.

Peak sun hours describe solar energy, not the length of the day. NASA POWER monthly averages are for a horizontal surface, not your tilted roof; they are historical estimates, not a weather forecast.

Compare rated panel power with its full front area at the standard irradiance of 1000 W/m². This is nameplate efficiency, not a prediction of real outdoor output.

Enter cell temperature, not air temperature, and the panel's power temperature coefficient. The estimate holds sunlight constant and only models the temperature effect.

Start with first-year generation and an assumed yearly decline. The constant decline is a scenario, not a forecast or a manufacturer's warranty.

Size nominal storage for your backup load, duration and usable battery depth.

Estimate how long your existing bank can run a steady average load.

Compare nominal battery sizes under editable chemistry assumptions.

Estimate charging duration between two battery charge levels.

Size a portable power station from the running load, backup hours and usable battery capacity. Check both continuous output and the starting surge in the manufacturer's specifications.

Convert battery capacity using its nominal voltage. Nominal energy is not the energy available at the socket; usable depth and conversion losses still apply.

Separate continuous power, apparent power and short starting surges.

Screen one MPPT input against temperature-adjusted string voltage and current limits.

Compare your upfront cost with projected savings over a chosen period.

Compare total spending over 5, 10 or more years, including your remaining grid bill.

Model self-consumption, grid imports and export credits using your own rates.

Add your local equipment quotes and installation expenses in one currency.

Estimate fixed monthly payments and total financing cost.

Compare added battery cost with savings from shifting surplus solar into later use.

Use generation, consumption and directly used solar electricity from the same period. This energy balance does not predict hourly overlap or model battery charging.

Compare the same daily energy and use one currency throughout. Prices stay fixed; financing, replacements and equal backup reliability are not modelled.

Estimate conductor area for a chosen DC voltage-drop target.

Check cold string voltage and estimate input and battery-side current requirements.

Estimate spacing on level ground from panel length, tilt and the sun's elevation at your chosen design time. This two-dimensional shadow check does not cover every sun direction or roof obstacle.