Solar + EV integration
Not every circuit gets covered equally during an outage. Add your battery size, circuits, and priority order to see exactly what's covered, for how long, and where EV charging fits in.
How it works
Step 1
Think honestly about what you genuinely need first during an outage, not what you'd like to have if capacity were unlimited.
Step 2
A clamp meter or your circuit breaker panel labels can help confirm real wattage rather than guessing.
Step 3
If reliable transportation is critical during outages for your household, consider moving EV charging up the priority list even if it costs coverage elsewhere.
A fixed battery capacity has to be allocated across every circuit that might draw from it during an outage, and the order in which circuits are prioritized determines which ones actually get covered when capacity runs short. This calculator applies a strict waterfall allocation, fully covering the highest priority circuit first, then moving to the next, until capacity is exhausted.
A refrigerator or internet router draws very little continuous power, so covering them for a full 24 hours consumes only a small fraction of typical battery capacity. High-draw circuits like a well pump or an EV charger consume capacity far faster, which is why even a well-sized battery can run out of capacity for these circuits well before reaching a full day of backup coverage.
Most households naturally rank refrigeration, communication, and water access above EV charging when thinking through outage essentials, since these directly affect immediate safety and comfort. Given how much capacity EV charging consumes relative to these lower-draw circuits, a factor the depth of discharge vs cycle life calculator also touches on, it often ends up with little or no remaining battery capacity under a typical priority ordering, unless a household specifically decides otherwise.
Priority order should reflect your household's actual needs and circumstances, not a generic default. A household with a medical need for reliable transportation, or one where the EV serves as the only vehicle, might reasonably choose to rank charging higher, accepting reduced coverage elsewhere as a worthwhile tradeoff.
If EV charging coverage looks insufficient for your needs, check the solar battery triple sizing calculator to see what additional battery capacity would cost, or consider whether the EV itself could serve as backup power through V2H equipment instead. Don't stop here, the critical loads only sizing calculator covers the rest.
Questions
Often not, if it's ranked last among typical household priorities. In a common example with a 13.5 kWh battery covering refrigerator, internet, a well pump, and lighting first, EV charging received zero hours of coverage over a 24-hour target, since higher-priority circuits used the full battery capacity.
Refrigeration and internet or communication circuits are commonly ranked highest, since they use very little power but provide continuous, essential value. A well pump or medical equipment often ranks next, followed by limited lighting, with higher-draw conveniences like EV charging usually ranked lowest given how much capacity they consume.
Battery capacity is measured in kWh, which is power in kW multiplied by hours running, so a 1,000 watt well pump running continuously consumes 24 kWh over a full day, far more than a 13.5 kWh battery alone can supply. High-draw circuits eat through available capacity much faster than low-draw circuits like a refrigerator or router.
Yes, priority order is a personal decision based on what matters most during an outage for your specific household. Someone who needs guaranteed transportation access during extended outages, like for medical appointments, might reasonably rank EV charging higher than this tool's default order.
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