THE SHORT ANSWER
Kilowatts describe power at a moment; kilowatt-hours describe energy stored or delivered over time. A complete battery review needs both plus a load plan.
Translate the units
A battery energy rating in kWh is not the same as its continuous or peak power in kW. DOE describes storage as a way to use electricity at another time. [1] The proposal should show usable-energy assumptions and applicable power limits for the exact configuration.
Match power to simultaneous loads
List equipment that may operate together and note motors or compressors with starting demand. The designer should explain whether the battery, inverter, transfer equipment and circuit arrangement can support that combination. Do not add appliance nameplates without professional interpretation and call it a design.
Model energy over an outage
Create a simple hour-by-hour scenario: refrigeration cycles, lights, communications, well or medical needs, and limited cooling. Ask how reserve settings and conversion losses are treated. Runtime is a scenario result, not a fixed promise printed on the battery cabinet.
Include solar recharge conditions
Ask how the system behaves after stored energy falls, whether solar can restart and recharge during an outage, and what conditions limit it. Cloud cover, array capability, load and equipment state all matter. A sunny-day example should not be presented as every-storm performance.
Save the tested operating plan
At commissioning, document protected circuits, settings, owner controls and any load-management behavior. Practice the recommended owner steps without forcing a real grid failure. Keep manufacturer instructions and service contacts accessible if internet service is unavailable.
Before your next conversation
- Record continuous and peak kW.
- Record usable-energy assumptions.
- Model simultaneous loads by hour.
- Keep the commissioned circuit plan.
Primary sources
- U.S. Department of Energy: Homeowner’s Guide to Going Solar
Primary source reviewed September 10, 2026. Utility rules, equipment availability, project design and contract terms remain specific to the property and proposal.
Planning examples and questions are Origin’s editorial guidance, not a property-specific diagnosis, engineering design, tax determination or promise of savings. Manufacturer and utility references do not imply an affiliation with Origin.
Make the decision specific to your home.
Use the backup planner before requesting a battery quote.
Discuss battery options →Scope, pricing and availability are confirmed for your property. A request is not a confirmed appointment.