Free Energy Calculators
Every assumption is shown. No fake savings promises. Model your situation with real numbers before you talk to installers.
Transparent calculations
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All calculators show their methodology and let you adjust assumptions.
Solar Calculator
Estimate daily and annual solar generation for your location and system size, with transparent assumptions.
System Size Calculator
Find the right solar array size from your annual usage, roof space and goals.
Battery Sizing Calculator
Size a home battery for evening load shifting or whole-home backup.
EV Charging Calculator
See how long it takes to charge your vehicle and what it costs per charge or per month.
Solar Payback Calculator
Model your solar payback period with different system costs, usage and export assumptions.
Electricity Cost Calculator
Understand your usage and calculate what you actually pay per kWh across different tariff structures.
About these calculators: All results are estimates based on publicly available data and stated assumptions. We do not make savings guarantees. Actual performance depends on weather, equipment quality, installation, shading and other site-specific factors. See our disclaimer for full terms.