Meet the Next-Generation Bus
The next-generation public transit bus is already rolling on the streets of several North American cities. Long Beach California has recently joined a growing list of cities outfitting electric buses with "induction charging" — a wireless technology that charges their batteries on the go. The wireless system works when one charging pad is attached to the bottom of an electric bus and another is planted in the road at a key point along the transit route. After the bus stops over the pad in the road, the induction charge sends power to the battery via a wireless transfer that can travel across several inches of airspace. A few minutes later — depending on the size of the battery — the bus is ready to resume its route.
WAVE, in partnership with Utah State University, developed the first solid state 25kW wireless power transfer charging system in North America for bus transit. The wireless charging unit is the first high-power, high-efficiency wireless power transfer system capable of transferring enough energy to quickly charge an electric vehicle. The system offers multiple advantages to traditional electric bus charging. Chief among them is that a wireless bus doesn't have to be taken off the road to get a full charge from a depot. It can last the full transit cycle of 16 hours by stopping over the charging pad a couple times during the day, whereas a traditional electric bus must be replaced halfway through its cycle by another bus with a full battery.
That advance gives transit agencies great flexibility. Some will be able to reduce the size of the bus fleet. Others can extend the duty time of a bus by charging it throughout the day. Still others may build buses with smaller batteries, which is great for both performance and maintenance. All these options should save a transit agency money while increasing efficiency.
We're referring, largely, to inductive charging - the ability to manipulate an electromagnetic field in order to transfer energy a very short distance between two objects (a transmitter and receiver).
We have found that others are not that far behind. Here are some of the prostpective public transit bus platforms in the development.
Formula 1 Buses
If we seay "Formula 1", we are prety sure bus is not something coming to a mind. Still, Williams has adapted the flywheel it used in its 2009 Formula One car – and fitted it to buses. It can save 20 to 30 per cent on fuel, and this fuel saving corresponds directly to an equivalent emissions reduction – important, as air quality in cities is a big issue.
The Williams flywheel harnesses kinetic energy when the bus brakes, and then feeds back to power the engine when it's running again. Another British company, Parry People Movers, uses the same gizmo to power its light tram-trains. But the flywheel's use on buses could lead to cleaner air and lower fuel bills. Unfortunately the flywheel doesn't permit buses to accelerate from 0mph to 100km/h in 2.1 seconds. At least not yet.
Precocious inventors at start-up company Vantage Power think they can make buses cleaner and cheaper. They have a design which retains the bus's diesel engine, but scales it back from a hefty seven litres to a mere 2.2 – the same as an estate car. The engine powers an electric generator which in turn charges a battery pack. The battery pack then powers an electric motor which runs the bus.
Combining series of hybrids the on-board energy storage system serves the purpose of buffering the peak power demands from acceleration and regenerative braking, whilst the on-board generator provides a smoothed average power output to recharge the energy storage system. This provides a very different function to a pure electric vehicle where enough energy must be stored in the battery until the vehicle can reach its next infrastructure recharging point - be it wireless induction charging or plug-in.
Based on the latest and safest lithium-ion chemistry cells from accredited and established high volume suppliers, Vantage has created one of the most innovative traction batteries in the industry. At the heart of the vehicle and the vehicle drivetrain, the traction battery has been purposefully designed for heavy duty series hybrid and pure electric drives.
One of the unique features of this battery system is that it can be interchangeably optimised for either the hybrid or the pure electric drivetrain variants. This is due to the modular packaging concept and adaptable control system, which also allows it to be easily modified for OEM custom requirements.
Natural-gas-powered buses are touted as being eco-friendly. Yet as we've come to realise recently, thanks to "fracking", no form of natural gas is totally green. For a greener bus you need to go all electric, if you charge it up from renewable sources. Some municipalities that have previously bought natural-gas buses in bulk, but is now switching to electric models - ebus.
Chinese manufacturer BYD (it stands for the catchy Build Your Dreams) are world leaders in the field. Battery power for the BYD ebus has been designed specifically to meet customer requirements for safety, energy density and low cost, making the BYD Fe Battery the battery of choice. The Fe Battery is the Lithium-iron Phosphate Battery that BYD has developed to power its cars, buses and forklift trucks. Utilising years of experience in battery technology, the BYD Fe battery is safe, stable, environmentally friendly and ensures a longer lifetime.
Thanks to fast charging technology, BYD ebus can be fully recharged in around 5 hours and able to run for 250km on a single charge in urban conditions. The BYD ebus has no tailpipe and therefore produces zero emission and helps improve air quality. The energy consumption of BYD ebus is around 130kwh/100km in urban conditions, saving up to 70% of fuel costs. The longer the drive, the better the savings.
The BYD design is priceless. The non-step entrance coupled with a wheelchair ramp gives easier access for wheelchairs and strollers to the barrier-free main aisle. Electronically controlled air suspension is designed to adjust the body up and down. The bus is able to lower to approximately 80mm on the kerb side, giving easier access for passengers. All non-step compartment assures safer and smoother movement in the bus. A high ceiling and wide open space inside the bus make for a comfortable journey for standing passengers. The interior of wide non-step compartment with raised rear section is optional dependent on the different battery packs position. A wide aisle with step to the raised rear passenger area has handrails installed to ensure safe movement for passengers.
The BYD ebus instrument panel is state-of-the-art. It has a large TFT screen with superior brightness and contrast. The panel provides the driver with real time driving information, such as motor rotation speed, running speed, mileage, and dump energy levels. Logically organised gauges and controls provide the ultimate in driving convenience. The clear view provided by the rear door monitor eliminates the driver’s blind spot and ensures safe operation of the door.
Well, the future is already here!