Understanding the Level 1 vs Level 2 decision
Speed and solar offset are two different questions
Level 2 charging is roughly 6 to 7 times faster than Level 1 in raw power delivery, which matters if you need a full charge in a few hours. Solar offset, on the other hand, measures how much of your daily driving energy can come from solar rather than the grid, and that number depends on your array's total daily output relative to your daily energy need, not on how fast the charger delivers it. A light commuter can often hit the same offset percentage on either charger, just spread across more hours on Level 1.
When Level 1 is genuinely enough
A driver covering 30 miles a day in a typical efficient EV needs around 7 to 8 kWh of battery energy daily, which a Level 1 charger left plugged in overnight or during a full workday can usually supply without issue. Level 1's main advantage is cost, since it uses a standard 120-volt outlet already present in most garages and requires no electrical work, while Level 2 requires a dedicated 240-volt circuit and often a panel check, costed out in the total cost including financing fees calculator.
When Level 2 becomes worth the install cost
Higher daily mileage, a second EV in the household, or simply wanting a full charge within a few hours rather than overnight all push the decision toward Level 2. A driver covering 80 or more miles a day may find Level 1 charging physically can't keep pace with daily energy use, since 24 hours of Level 1 charging caps out at roughly 34 kWh even under ideal conditions, less once charging losses are factored in.
Array size can make Level 2 look like Level 1
If your solar array's derated output is smaller than a Level 2 charger's rated power, the charger simply can't pull more than the array can supply, so the extra speed capability of Level 2 hardware goes unused during solar-only charging. In that scenario, the offset percentage on both chargers converges, and the practical difference becomes charge time on cloudy days or grid-assisted sessions rather than daily solar coverage.
Taking this result further
If Level 2 shows a meaningfully higher offset, check the EV charger sizing with solar calculator to confirm your panel can support the larger breaker before budgeting for the upgrade with the home EV charger installation cost estimator. The battery charge time from solar calculator fills in the rest of that picture.