Understanding your weekday vs weekend charging pattern
Why solar overlap often differs by day type
A household with a typical work commute often isn't home during peak solar production hours on weekdays, meaning charging happens overnight after returning from work and misses most of that day's solar entirely. On weekends, the same household might be home during the day, allowing the charger to run directly during peak sun hours and capture a much higher share of self-consumed solar.
What this means for annual cost estimates
A single flat solar offset percentage applied to all charging can understate weekday costs and overstate weekend costs, or vice versa, depending on which pattern the flat figure was based on. Splitting the calculation by day type, as this tool does, gives a more accurate picture of where your actual charging costs concentrate, similar to how the annual true up payment estimator breaks down billing periods, throughout the week.
Strategies for closing the weekday solar gap
Some EV owners with sufficient range buffer intentionally delay a portion of weekday charging until a day off or weekend, a pattern reflected in EIA electricity data on weekday-versus-weekend demand, batching accumulated charging need into a session that better overlaps with solar production. A home battery offers a more automatic solution, storing midday solar production while the household is away and discharging it during evening weekday charging, effectively shifting solar's timing advantage without requiring manual schedule changes.
Why this matters more for some households than others
A household with a flexible schedule, remote work, or minimal weekday driving may see much less of a weekday-weekend gap than a household with a strict commute and long workday. Understanding your own specific pattern, rather than assuming a generic split, gives a more useful and personally relevant cost picture.
What this result means for your next step
If the weekday-weekend gap looks significant, check the solar battery triple sizing calculator to see what battery capacity would help shift midday solar to evening charging, or the charging schedule optimizer tool for more scheduling strategies. Night charging needs stored power. The battery charge time from solar calculator in our Battery & Storage section can help you size a battery for the miles you drive each day.