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The published example examines a 290 m² home with modelled annual electricity demand of 9,583 kWh and solar generation of 8,669 kWh. The resulting 914 kWh gap is presented as a design question to address, rather than proof of net zero performance.
These are case-study assumptions from a presentation, not measured operational results or a guarantee for another property. Use the lesson to connect a claim with its boundary, method and supporting evidence.