United States · Solar & storage
Plug-in solar calculator
How much battery is worth adding—if any? Compare 0–5 kWh and see what storage adds to your solar savings.
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Your next decision
Compare first. Buy second.
- Check whether you can use more solar directly during the day.
- Compare the extra battery savings with its full added cost.
- Verify the equipment, connection and local rules before ordering.
Common questions
Can the answer be no battery?
Yes. The calculator compares a battery with the same solar setup without one. A profitable solar system does not automatically make a battery worth buying.
Is this a savings guarantee?
No. Weather, real load patterns, tariffs, shade and equipment vary. The weather variation only changes one assumption; it is not a statistical confidence interval.
Does this model every battery system?
This models a DC-coupled battery sharing one AC output limit. Separate AC batteries, backup power and time-of-use tariffs need different models.
What happens to my inputs?
The calculation runs in your browser. The current scenario stays in this tab. Save locally keeps it on this device beyond the tab; you can delete it later.