Battery electric bus
A battery electric bus is an electric bus that is driven by an electric motor and obtains energy from on-board batteries. Many trolleybuses use batteries as an auxiliary or emergency power source.
History
The London Electrobus Company started running the first ever service of battery-electric buses between London's Victoria Station and Liverpool Street on 15 July 1907.The first battery buses were mostly small, mini- or midi- buses.
The improvement of battery technology from around 2010 led to the emergence of the battery bus, including heavier units such as standard buses and articulated buses.
China was the first country to introduce modern battery electric buses in large scale. In 2009 Shanghai catenary bus lines began switching to battery buses.
In September 2010, Chinese automobile company BYD began manufacturing the BYD K9, one of the most popular electric bus.
The first city to heavily invest in electric buses was Shenzhen, China. The city began rolling out electric buses made by BYD in 2011, with the objective of having a fully electric fleet. By 2017, Shenzhen's entire fleet of over 16,300 buses was replaced with electric buses, the largest fleet of electric buses of any city in the world.
According to Bloomberg, "China had about 99 percent of the 385,000 electric buses on the roads worldwide in 2017, accounting for 17 percent of the country’s entire fleet." Chinese cities are adding 1900 electric buses per week.
Other events
- In 2011, bus manufacturer Contrac Cobus Industries from Wiesbaden announced the Cobus 2500e.
- In autumn 2012, Czech manufacturer Inmod supplied a vehicle has 22 seats, 35 standing places and a range of a day, up to can be extended. The bus is recharged with a quick charger twice a day for one hour. Its maximum speed is.
- Beginning in 2012, the Wiener Linien on bus routes 2A and 3A use electric buses. They are charged to the end user via a pantograph, which is applied to short catenary pieces. These are fed by the tram catenary. The cars have a range of around.
- In May 2013, a battery bus began running between the airport and Palexpo in Geneva, Switzerland. This bus can be partially charged within 15 seconds. At the end of the line the charging process takes three to four minutes. The project cost five million francs.
- The Regional Transport Ruhr-Lippe GmbH began operating an electric minibus as a Quartierbus in May 2013. Vehicle range is approximately. Recharging takes about three hours when fully discharged. Recharging consumes over 1.5 hours during the lunch break.
- In 2013 battery buses entered service in the Netherlands.
- In Germany in 2013 battery buses were undergoing tests in Bremen and in Bonn.
- The largest battery bus fleet is in Dalian, China. It includes 600 BYD buses. The purchase of a further 600 vehicles was planned for 2015.
- In 2015 BYD planned to launch the first battery-double-decker bus.
- In Braunschweig battery buses entered regular service at the end of 2013. The "Emil" project uses inductive charging. Both vehicles and charging stations were developed with Bombardier.
- In Gumi, South Korea in 2013 a road section was modified to allow inductive charging while driving. The technology was to be tested with two electric buses.
- In California, battery school buses since the end of October 2013 because of significantly lower operating costs, are used.
- In Hamburg Rampini battery buses entered service in 2014 on line 48.
- Dresdner Verkehrsbetriebe together with the Fraunhofer Institute for Transportation and Infrastructure Systems began testing battery buses on November 3, 2014. On June 17, 2015 passenger service began on the first route in Saxony. A four-minute stop at the last stop provides sufficient charge, with a high-power charger to preheat the passenger compartment.
- The Munich public transport company began testing battery buses in 2008. Experiments with Ebusco vehicles of were expected to reach a range of using lithium iron phosphate batteries.
- In Pinneberg testing began in 2014.
- In September 2015 four battery buses entered service in Berlin. The Solaris Urbino 12 charge by induction at the last stop.
- In July 2015 the Schleswig-Holstein Rendsburg purchased a Sileo battery bus with a range of for 450,000 euros. The bus does not charge during operation and can be operated for half a day. The bus is charged from a rooftop photovoltaic system.
- In Bonn test entered regular service in 2013. The range is at least.
- Botosani, Romania planned for public transport to operate fully electrically. at a conversion cost of 20 million euros.
- In October 2015 the double-decker buses were converted to BYD electrics with a range of. London's center-city access toll is waived for battery buses.
- In 2015, BYD aimed to sell 6,000 of its buses worldwide. BYD is the world leader in the sale of electric vehicles.
- The California Department of Transportation contracted with Antelope Valley Transit Authority to switch its buses to 85 BYD battery buses with a range of at least. Models include a low-floor transit bus, a low-floor articulated and a commuter bus. Savings were expected to be $46,000 per bus per year.
Charging
Scheduling
Charging electric bus batteries is not as simple as refueling a diesel engine. Special attention, monitoring, and scheduling are required to make optimal use of the charging process, while also ensuring proper battery maintenance and safekeeping. Some operators manage these challenges by purchasing extra buses. This way the charging can take place only at night. It is a safe solution, but also very costly and not scalable.Another solution is ensuring that the vehicle daily schedule takes into account also the need to charge, keeping the overall schedule as close to optimal as possible.
Today, there are various software companies that help bus operators manage their electric bus charging schedule. These solutions ensure that buses continue to operate safely, without any unplanned stops and inconvenience to passengers.
Supercapacitors can be charged rapidly, reducing the time needed to prepare to resume operation.
Communication standards
For communication between charger and electric bus the same ISO 15118 protocol is used as for passenger car charging. The only differences are in the charging power, voltage and coupler.Pantographs and underbody collectors
and underbody collectors can be integrated in bus stops to quicken electric bus recharge, making it possible to use a smaller battery on the bus, which reduces the initial investment and subsequent costs.Advantages
Battery electric buses offer zero-emission, quiet operation and better acceleration compared to traditional buses. They also eliminate infrastructure needed for a constant grid connection and allow routes to be modified without infrastructure changes compared to a Trolleybus. They typically recover braking energy to increase efficiency by a regenerative brake. With energy consumption of about, the cost of ownership is lower than diesel buses.Disadvantages
As of 2016 battery buses have less range, higher weight, higher procurement costs. The reduced infrastructure for overhead lines is partially offset by the costs of the infrastructure to recharge the batteries. Battery buses are used almost exclusively in urban areas rather than for long-haul transport. Urban transit features relatively short intervals between charging opportunities. Sufficient recharging can take place within 4 to 5 minutes usually by induction or catenary.Although the initial purchase cost of the vehicle is higher than conventional and hybrid buses, Proterra, Inc. asserts the total cost of ownership over a twelve-year lifecycle is lower thanks to reduced maintenance and energy/fuel costs.