Separate power from stored energy
Power, measured in kilowatts, describes a rate of energy use or supply. Stored energy, measured in kilowatt-hours, describes an amount available over time. Both matter when discussing a battery system.
Two products with similar stored energy may support different loads. Ask the proposal to identify the exact models, usable storage, power capability, and any relevant starting-load limits instead of comparing the number of boxes on the wall.
Build a load list before requesting a count
A whole-home electric bill is useful background but does not identify the exact backup demand. Appliance records, usage patterns, and a professional assessment can refine the estimate.
- Must-have appliances and circuits during an outage.
- Large loads such as AC, pumps, electric heating, or vehicle charging.
- Loads you could defer or use at different times.
- The period you want the backup scenario to cover.
- Whether solar or another supported charging source is part of the design.
Use simple arithmetic only as an illustration
For illustration, a constant 1 kW load used for 8 hours consumes 8 kWh. That calculation describes energy use; it does not specify a battery product or guarantee eight hours of backup from a unit advertised at 8 kWh.
Real proposals need to account for usable energy, system losses, starting conditions, changing demand, and the selected equipment’s limits. If solar replenishment is assumed, ask what happens under a less favorable weather scenario.
Ask what changes between the proposed options
Sun Ray provides a project-specific battery proposal. Begin with your address, existing equipment, and priorities; we can identify what further information is needed before a quantity or installed price is confirmed.
| Option difference | Question to ask |
|---|---|
| More stored energy | Which operating scenario lasts longer under the stated assumptions? |
| Different power capability | Which additional or simultaneous loads can be supported? |
| Different backup scope | Which circuits are included or excluded? |
| Future expansion | What equipment and additional work would expansion require? |