System sizer

Let the load define the system.

Build a load inventory, preserve must-run energy, and pressure-test battery storage, solar recovery, continuous inverter output, startup surge, and controller current before comparing components.

Appliance load list

Turn the equipment you already know into planning inputs.

Classify must-run and shed-able energy, then mark the devices that overlap and record the highest documented startup demand. The example rows are editable starting inputs: replace their values with appliance labels and the operating pattern you expect to use.

ApplianceRunning WStartup WHours / dayQtyCriticalIn peak
Critical energy—
Optional energy—
Running peak—
Startup demand—

Planning tool

Build a planning baseline

Separate must-run energy from shed-able loads, then pressure-test battery reserve, solar recovery, continuous power, and startup demand.

View assumptions and sources →

The values below are editable planning baselines. Change the few inputs you know; open Advanced assumptions only when they change your decision.

Advanced assumptionsChange storage reserve and DC architecture after the load boundary is defined.
Battery planning range——
Solar recovery range——
Continuous inverter check——
Startup surge check——
Controller current range—battery-side current check; verify PV open-circuit voltage separately
Battery-side protection check——
Dominant assumptions

What moves this result most

    —

    Next decision

    Compare this baseline against roof space, seasonal production, and your actual equipment documentation.

    Planning brief

    Turn the estimate into checks you can verify.

    Use this pre-purchase brief to compare component documentation against the plan you just built.

    Next decision

    Verify assumptions and sourcesTranslate watts into panelsPlan charging and recovery

    Plan tools

    Keep this useful version close, shareable, and easy to revisit.

    Reset inputs

    Optional support

    Keep practical planning tools available.

    If this result made the next decision clearer, an optional contribution helps cover hosting, source reviews, and continued improvements.

    Choose a small tip on Ko-fi

    Battery storage

    ——

    Inverter

    ——

    Solar array

    ——

    Charge controller

    ——

    What becomes constraining first?

    —

    —

    —

    Must match

      Optional paths

        Resolve before shortlist

          Before selecting components: verify manufacturer documentation for surge power, BMS discharge and charge limits, PV input voltage, temperature limits, cable sizing, fuses/breakers, mounting, and local requirements.

          What it models

          Critical and optional energy, reserve days, nominal voltage, sunlight, running load, startup demand, and visible baseline/pressure assumptions.

          Installation checks

          Use the baseline to check site shading, mounting, wiring, protection, equipment compatibility, permits, and local installation requirements.