Matching charging capacity to everyday driver needs

All levels of charging have an important role to play. For long-dwell locations, the approach is to right-size charging levels based on average driving need.

Specifically, the average need is 25 – 35 miles per day for a typical urban and suburban resident.

For residential settings, cars are parked an average of over 12 hours. Charging needs can be satisfied with Level 1 (dedicated 120V 20-amp circuit, delivery up to 16 amps and 1.9 kW to the vehicle) or power-managed Level 2 (1.9+ kW) which provide 40 – 70+ miles of charge overnight, avoiding more expensive electrical capacity upgrades. Power-managed Level 2 systems can provide higher average charging but Level 1 provides lower cost. Research on charging needs based on actual commute patterns indicates that 94%+ of driver's actual driving needs are satisfied with 1.65 kWh charging level. 

Workplaces have somewhat shorter dwell times and managing charging at higher power levels may be appropriate.

Finally, fast charging (Level 3) provides essential support for long-distance trips, high utilization services such as ride-hailing, and some gap-filling support for those with no access to charging or whose periodic needs exceed their day-to-day charging option.