A 3 kWp array and 10 kWh battery describe equipment, not guaranteed autonomy. A professional buyer needs to know which loads remain supplied, for how long and under which conditions. Remote accommodation needs that definition before pricing.
Start with a load profile
Our proposal separates essential services, comfort and deferrable loads. Refrigeration, communications, heating and hot water have different schedules and peaks. Record power, daily energy and seasonality, then agree who accepts emergency-mode limits.
PVGIS, developed by the European Commission’s Joint Research Centre, can simulate off-grid systems with battery storage and daily consumption variation. It supports solar-resource and supply studies; it does not certify a manufacturer. An annual surplus can coexist with periods of empty storage.
A transparent autonomy example
A nominal 10 kWh battery with an assumed usable fraction of 80% provides 8 kWh before losses. A hypothetical constant 400 W load gives 20 hours by division. These are teaching assumptions, excluding degradation, temperature, losses and new solar input; they do not describe a validated product.
Define limits and acceptance
- Usable capacity, available power and reserves.
- Weather scenario and hourly load profile.
- Behaviour after loss of communications or automatic control.
- Protection, installation, maintenance access and equipment documents.
- Handover test and backup conditions.
LFP chemistry should not be marketed as incapable of catching fire. A professional offer substantiates safety and operation with system documents, and ties autonomy claims to explicit conditions.
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Sources and scope
Sources reviewed 11 October 2026. Handover and control lists are CasasCápsula editorial recommendations; they do not replace project calculations, tests or documents.