|PJBell.com | Technology | Projects | About | Services | FAQ | News | Contact|
School Buses, the go to market opportunity for Electric Vehicle technology - Peter Bell
Each year, one school bus emits the equivalent of 114 cars, according to the EPA (Environmental Protection Agency).
Biodiesel and other clean diesel technologies can reduces school bus emissions, but the ultimate zero emission vehicle is the Electric Vehicle.
Because of a school bus's unique two trip duty cycle, low mileage, tolerance for lower handling performance and long life cycle, they offer the ideal platform for conversion to all electric power and gives the Electric Vehicle (EV) technology an ideal come to market opportunity.
Electric buses possess numerous advantages over their traditional internal combustion counterparts, including reduced maintenance costs, reduced fuel costs, reduced noise levels, and zero emission levels.
The traditional challenges facing electric vehicles, such as heavy batteries, short range, in-wheel motors reducing handling performance and low top speed are not a problem for a school bus.
Unique go to Market Opportunity
The nations fleet of school bus vehicles on the urban cycle offer the ideal opportunity to bring Electric Drive technology to the commercial market. The school bus operator is very cost conscious fleet operator and cost per mile is a critical part of daily life ensuring the students get to school on time.
Weight is not such a challenge
Weight is not an issue as school buses transport kids who are lighter than adults, so if the vehicle is heavier than a regular passenger bus due to all the batteries, this does not pose as big a problem as a heavy private passenger car.
Ultra Capacitors can be used to protect the battery from high current inflow and outflows. The QED Mini from PML Flightlink uses a 350V, 11 Farad ultra capacitor to protect the battery from the biggest spikes, such as discharging the high current for acceleration and to accept the regen power back from braking.
In-Wheel Electric Motors are an option
In-wheel electric motors are very attractive technology to the Electric Vehicle manufacture as they enable the vehicle to dispense with transmission, drive shafts and disk brake equipment. This greatly reduces the vehicles complexity, cost and increases reliability dramatically.
The problem with current in-wheel motors is their weight even considering you can remove the disk brakes and calipers for 100 regen. braking. Because this weight is applied to the "Un-sprung Weight" of the suspension, every extra pound of weight has a dramatic effect on the handling performance of the vehicle.
School bus buyers on the other hand are not so sensitive to reduced handling performance. The average speed of a school bus ranges from 25 to 50mph and their drivers are not cornering the vehicle at the edge of the performance envelope. In addition, fleet school bus fleet operators are buying transportation to get kids from A to B and esoteric performance criteria like handling is not high on the list of buying criteria.
Limited range of Electric Drive Technology is not an issue
The country's longest school bus route is 125 miles, but the average route is much shorter at 68 miles. Because the length of even this average route is 34 miles out and 34 miles back, current range limits on electric vehicles are not an issue.
Lead Acid batteries give around 30 Wh/kg, Nickel Metal Hydride approximately 60 Wh/kg and Lithium-Ion can be as high as 150 Wh. The major push is with Lithium-Ion battery technology with new developments enabling energy density that is approaching 200Whr/kg and current battery's like A123 System's 32157 model offering a volumetric density of 260 Wh/L.
These kinds of advanced batteries are expensive if the very latest lithium-ion battery technology is utilized. The beauty of the of the school bus fleet market is that kind of performance cheaper iterations of battery technology can deliver an adequate range, so you don't have to break the bank to go all electric.
Charge at night and again during school hours
An all electric school bus can take advantage of low cost, night time electricity to recharge and be ready for school in the morning. Once they have delivered the students to school in the morning, they can hook up to the grid to take a top up recharge, ready to take the kids back home in the afternoon.
The daily commuter driving to work everyday is one of the few other vehicle users that offer the electric vehicle manufacturer the same duty cycle. The key difference is that these buyers of a commuter vehicles are not as sensitive to the per mile cost as a school bus operator and require the vehicle for other duty cycles like weekend or vacation travel.
The estimated grid comparison price per gallon is approximately 60 cents per gallon, which represent considerable cost savings when compared to the price of diesel fuel.
Basic Bus Fleet Information
The nation's school bus fleet comprise 440,000 vehicles, with 40,000 new vehicles joining the fleet each year. These busses travel nearly 5 billion miles per year and consume over 1 billion gallons of diesel per year. These busses transport approximately 25 million children and make approximately 10 billion student trips each year.
The average suburban school bus travels 68 miles per day, with the longest school bus route in the nation being 125 miles long. The average yearly mileage is approximately 12,000 miles per year. The average school bus speed attained on these trips is somewhere between 25 and 50 mph.
The average school "C" class of bus has a 230 hp motor generating 700 ib/ft of torque and will attain an average fuel economy of 7.5 miles per gallon. The average school bus will consume 2,250 gallons of diesel fuel per year and at $2 per gallon, will incur $5,000 per year in fuel costs.
Private passenger vehicles a tough 1st market for EV technology
Tesla, ZAP and many other EV (Electric Vehicle) companies are taking on a very tough challenge by attempting to market an all electric private car. The competition for this kind of vehicle is the massive variety of vehicles on the worldwide auto market brought to the consumer by the world's automotive industry.
The auto industry is arguably the biggest business in the world. This industry has had over 100 years to perfect their vehicle range powered by the internal combustion engine, so the competition for an all electric vehicle is very highly evolved.
The electric vehicle manufacturer wanting to compete in the private passenger vehicle market has to make a vehicle that is at least as good as the internal combustion powered competitor, which is a big hurdle in its own right. Due to electric drive technology currently being more expensive, the electric vehicle manufacturer then has to depend on the consumer's environmental concerns to choose the all electric option even though the product does cost more money.
These factors limit the electric vehicle to a very small, niche market.
Electric School Buses can make a big impact right away
The school bus market, especially vehicles destined for an urban cycle offer the ideal opportunity to bring all electric vehicle technology to a commercial market as an all electric bus has significant advantages over its diesel powered competition.
The really neat thing about the school bus market opportunity is that the oldest vehicles in a fleet and could be retro fitted electric drive first. This will ensure that the worst polluting busses are upgraded first and the nations children benefit from an immediate reduction in health risk.
© 2007 PJBell.com all rights reserved.