Know what the estimate means.

Power and energy are different

Watts and kilowatts describe power at a moment in time. Watt-hours and kilowatt-hours describe energy used over time. Inverter sizing needs simultaneous power and starting surges; solar array sizing begins with daily energy.

Solar production

The array tools use a simple energy balance: rated array kW × equivalent peak sun hours × retained energy fraction. This is not an hourly weather simulation. Enter a design-season solar resource and losses that reflect your site. Battery charging, shading and temperature can materially change the result.

Battery storage

Nominal storage is larger than delivered AC energy because only part of a battery may be usable and conversion is not perfectly efficient. The battery calculators do not model lead-acid discharge-rate effects, aging or temperature.

Financial scenarios

Financial outputs are undiscounted, editable scenarios in whichever currency you consistently use. They do not pull current utility tariffs, incentives or export rules. Savings and future tariff changes are assumptions. A negative net profit is shown rather than hidden.

Installation checks

Cable sizing covers DC voltage drop, not ampacity or code compliance. Controller sizing checks selected electrical limits, not all datasheet conditions. Tilt is a latitude-based heuristic. Roof space is an area allowance, not a structural or shading assessment.

Before installation

Have the actual layout, electrical protection, earthing, string configuration, equipment limits and roof structure checked by a qualified local professional. Each tool includes its specific formula and limitations.