There are about 550,000 school buses in United States and Canada. Each day some 26 million children ride on school buses.
For long school buses have been the ideal candidate to go electric instead of being diesel. Eliminating the exposure of the exhaust from diesel engines would be a significant health benefit. In addition, from the electric grid perspective the battery storage in the school buses could be a valuable resource for balancing the system, thanks to school buses having defined schedules, idle during the middle of the day and parked during the summer.
For all car buyers, regardless conventional car or electric car (EV), convenience is a prerequisite. For EVs the charging of the battery is an important part of the convenience.
Even though for most the daily use of an EV there is enough electric energy stored in the battery, range has always been an issue. One solution is a series hybrid vehicle (plug-in electric vehicle, PEV) with a small reciprocating engine as an onboard battery charger. For pure EVs (battery only) the solution for range has been to equip the car with a large battery. Tesla has been a leader in this respect. Model S base model has a 60-kWh battery providing 200 miles’ range. There is also a 90 kWh option providing 300 miles. Nevertheless, for long distance driving that range may not be enough. More energy than what can be stored in the battery is needed. Tesla early recognized the importance of developing a proprietary network of fast chargers, called super chargers. Access to their super charger network, which until last year was free, has been a selling point. The power of the super charger has been increased to 145 kW. It can charge a 90-kWh battery to 50 % of its capacity in 20 minutes.
Four German automakers, BMW, Mercedes, VW and Audi, in 2016 announced the roll-out of “ultra fast” chargers for EVs in Europe. These chargers will deliver 300 kW of power. At a first glance that high amount of power may give the impression it will provide a very fast charge. However, it is not a given, since lithium ion batteries have limitations how fast they can be charged. In fact, fast charging is more about lithium ion chemistries than the power of the charger.