A useful quote should explain what you are buying, what it is expected to produce, and which works are included in the price. Total capacity and the final amount alone are not enough for comparison.
- Exact models and quantities of panels, inverter and battery, where applicable.
- PV system capacity, usable battery capacity and key operating capabilities.
- Mounting structures, wiring, electrical protections, installation work and any modifications to the electrical panel.
- An estimate of production and financial benefits, with assumptions about consumption, energy prices and losses.
- Warranties, performance monitoring and agreed support.
- Total cost including VAT, exclusions, timeline and payment stages.
Ask for clarification on who is responsible for applications and documentation, and which third-party charges are included. If you want power during an outage, the required configuration must be explicitly stated. The presence of a battery alone does not prove that backup power is provided.
Read also: how to compare two solar PV quotes.