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Initial results from first phase of road trials for 40-ft BYD electric bus in Canada

25 January 2014

Consumption-to_Relative_Speed
2013 STO-AVT electric bus test results chart: BYD Electric Bus energy consumption (Wh/km) over speed (km/h). Click to enlarge.

The first phase of a ten-month trial for a 40-foot BYD battery-electric bus (which commenced the Summer of 2013) was completed in Gatineau, Québec and Ottawa, Ontario in December. (Although the bus drive is zero-emissions, in frigid weather bus-heating was supplemented with a small diesel heater integrated into the bus).

The evaluation, performed by the Société de transport de l’Outaouais (STO) in conjunction with AVT (the Société de gestion et d’acquisition de véhicules de transport), found that the average speed of drivers on Gatineau and Ottawa routes was 23 km/h (14 mph), and the resulting distance the BYD bus could travel at this average speed was 250 km (155 miles)—the equivalent of 1.3 kWh/km without air-conditioning and 1.5 kWh/km with air-conditioning, and full passenger loads).

The partial findings were presented at the 2013 EV/VE Conference and Tradeshow in Gatineau-Ottawa by Salah Barj, Director of Planning and Development at STO.

The report findings support BYD claims that the bus is efficient in the use of energy. BYD typically advertises a 250 km (or 155+ mile) operational range for its 40 foot bus. However, BYD claims that when driven by an operator who understands the vehicle and how to optimize regenerative braking, the bus range could well exceed 250 km.

The range is a direct attribute of the sizing of the BYD’s Iron-Phosphate battery. BYD provides the largest battery of any electric bus supplier today with a 324 kWh total energy storage capacity. Further, BYD claims (as shown in the chart above) that when bus average speeds increased up to the maximum speed of 70 km/h (43 mph), that the overall bus efficiencies increased to 0.75 kWh/km traveled (equivalent to 1.2 kWh/mile) and the difference between “with” and “without air conditioning” is lessened.

The battery-electric bus was supplied by BYD Company under a service agreement and continues its evaluations in partnership with the Société de transport de Montreal (STM) until Spring of 2014.

The BYD electric bus was nothing like anything we had seen or tested before, it was able to run our required 8-hour shift in service with only a night-time single charge at our bus garage. BYD’s bus itself has on-board chargers so that only 60 kW of grid AC power was delivered at night to the bus through a power interface. This made for very convenient charging of the electric bus so that no peak-rate power was consumed.

—Salah Barj

AVT was formed by Québec’s nine transit corporations for the evaluating of advanced, zero-emissions public transit technologies. The AVT team acquires buses and manages contracts for companies within the Urban Transit Association of Quebec (ATUQ) which includes: Société de transport de Montreal (STM); Transportation System Capital - Québec (RTC); BC Transit; Translink; Network transport de Longueuil (RTL); Société de transport de Laval (STL); Transit Corporation Levis; Société de transport de l’Outaouais (STO); Transportation Company Saguenay (STS); Société de transport de Sherbrooke; andSociété de transport de Trois-Rivières (STTR).

January 25, 2014 in Canada, Electric (Battery), Fleets, Heavy-duty | Permalink | Comments (23) | TrackBack (0)

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Pretty much a home run, it looks like.

Considering the frequent cold waves (to -34C since early November) the area is having this winter, the initial results are excellent and better than expected.

This may indeed be a real winner and a good 3 years ahead of equivalent Volvo Canada units.

AVT (Grouped Bus purchasing for 10 cities) will need between 200 and 400 electric city e-buses a year for the next 10 years or so to phase out existing diesel units.

All those e-buses will operate with clean Hydro/Wind energy.

I love EVs, but this bus is a disaster. Tt's best efficiency happens at 70 km/h, and it's horribly inefficient under 50 km/h! And we are talking about big motor + big controller (>90% efficient combo).

This thing is crying for a decent gearbox. Automatic transmission in a public bus, holy Jesus!
A team of 10 nissan leafs have better efficiency than this thing and will carry more people, it's ridiculous. Big transport is supossed to be MORE efficient.

@peskanov:
Horribly inefficient!
You jest.

This carries 31 passengers:
http://en.wikipedia.org/wiki/BYD_electric_bus

It does that using 1.5kwh/km at its worst with full air conditioning running, or 2.42kwh/mile

That comes to 78Wh/mile per passenger!

So it is around as efficient as a Leaf with 4 people in.

A 10mpg diesel bus at 33kwh/gallon for a 31 passenger bus uses around 1kwh/passenger/mile, or around 12 times as much energy.

Oops!
I lost the decimal place!
The diesel bus is uses around 3.3kwh/mile, of course, so the electric bus is around 1.5 times as efficient.

I was too generous in my mileage guess for diesel buses:

'The majority of transit buses today run on diesel fuel, and for good reason: diesel engines are a proven commodity that has been around since the 1800s, and diesel fuel is readily available. Diesel buses cost around $300,000, depending on what options are included, and average 2 - 3 miles per gallon.'

http://publictransport.about.com/od/Transit_Vehicles/a/How-Transit-Agencies-Decide-On-What-Buses-To-Purchase-Part-2-Propulsion-System.htm

So at 3mpg and 31 passengers they might use around 350Wh/mile, or be around four and half times less fuel efficient than the BYD bus.

The area has huge low cost clean Hydro/Wind e-energy surpluses till 2027 and much more can be installed on an as required basis.

Charging 4000+ large city e-buses overnight, when e-energy demand is down by up to 66% will not be a burden for the grid but a welcomed load leveling exercise.

The same could be said about the future 3+ million electrified vehicles in the area.

I would like to see if BYD has made updates to the chassis after reports of weaknesses in California.

To update my own post, BYD had stated that testing confirmed the safety of the buses.

http://www.businesswire.com/news/home/20131213005908/en/LA-Area-Transit-Officials-Tout-Electric-Bus-Company#.UuScUPuwoad

It ain't elegant, but BYD's use of of relatively heavy but very tough batteries is in my view more practical than, for instance, Nissan's attempts to use the Leaf with its small batteries which don't like being fast charged for taxi work.

Longer term for areas where it gets cold in winter I would like to see fuel cells used, at minimum for ancillary heating, where units are already being developed for truck use, as that would give a truly zero pollution at point of use solution.

Depending on costs, a fuel cell range extender would also greatly increase efficiency in cold weather.

Having said that, inelegant or not, the present BYD sound like an effective answer at the moment to me.

Davemart,
you made the calculations and got even even a worse result than me!
Comparing it to a diesel is a bit disingenuous, we all now ICEs are not effcicient. But most electricity come from coal and gas plants, and these not much more efficicient than a decent diesel bus (>30% eff.).
EVs can do better, and nearly all of them DO better. A city bus moves under 70 km/h most of the time, I see no reason for using a terribly inefficient automatic transmission optimized for maximum speed in an slow heavy duty vehicle. Also, the speed range is narrow, a simple gearbox will do. And it does not need to be manual, it can be a piloted one.
About big batteries: imho, when designing an EV money is better spent in lighter chassis/body materials instead of bigger batteries. Batteries age fast, body and chassis not (and are easier to recycle). And you get the benefit of less energy needed for operation.

A correction:
BYD official site mentions automatic transmission, but pictures and reports show direct transmission, in-wheel motors.
So, I have no idea why it has such a poor effciency at low speeds. Maybe they use a poor controller?

It could be that the 4 MPH versus 40 MPH efficiency includes lots of stops at 4 MPH. If you have to accelerate a large bus with lots of people many times, it takes lots of energy.

If you look at the efficiency curves for motors, they are efficient while running, but while producing large torque from stand still they take a LOT of power and are no where as efficient.

Wasted heat from e-motors and controlers could be used to keep (part of) the cabin and battery enclosures warm on cold days with an improved heat management system.

Of course (e-models sold in Canada) the cabin doors, windows, walls, ceilings, floors etc could be better insulated (like a hot water tank and green building) to reduced the heat required.

Battery operate vehicles need improved manufacturing techniques to reduce energy consumption in very cold places. The technologies and materials required already exist and are not so costly. It is more a resistance to change.

There should be plenty of controller/motor heat to keep a well insulated bus interior warm in stop and go conditions. They can use a heat pump on the controller to keep it cool and provide almost instant heat for the bus interior.

I don't know how much extra weight making the bus well insulated would take, but their design choice is to add a diesel heater, which they would presumably not do if there were a quick and easy fix using battery heat.

The Scandinavians also tend to use supplementary kerosene or diesel heating in electric vehicles, and they know a thing or two about vehicle usage in the cold.

It is not battery heat, you are heating the batteries in winter to get more range. It is heat from the controllers and motors and that can be quantified.

A very cheap existing polluting gas heater is the easy (effortless) way of doing it. That's probably why so many manufacturers use that approach.

Cleaner more efficient ways exist but require more design efforts. It does not have to weight more than gas heaters and gas tanks.

Well insulated aluminium bus bodies do not have to weight more than current steel bodies.

That is it, cost drives the decision, not what is "best". The thermal insulation would also be sound insulation. It would be nice to have buses that are quiet inside.

Over 60 years ago we were locally making and using aluminium city buses in our city. Those buses did not rust, weighted 4-tonnes less and could last 16+ years.

In the late 1950s, GM came around with its deep pockets and convinced our elected people that buying their heavier (+4-tonnes) all steel city buses was a better deal. It was not sp.

Our sole aluminium city bus manufacturer had to go bankrupt and close shop. The same happened to our 100+ electric trolley buses a few years latter.

In the 1960s and 1970s many GM steel city buses were replaced by 850 stainless steel subway cars.

In the 1980s and 1990s and up to today the remaining GM buses were replaced with Volvo low floor city buses and many articulated MAN city buses. Starting in 2014/2015 all diesel city buses will be replaced with BYD, Volvo or other aluminum electric city buses. The transition will take 10 to 12 years. Meanwhile, the first and second generation subway cars are being replaced with third generation units. The transition has started and will also take about 8 to 10 years.

Well this bus has a bit under 4 times the battery capacity of a Model S but I'm sure it weighs more than 4 times the amount and isn't nearly as aerodynamic. I doubt a model S could do 250km in the type of stop and go driving that a bus has to do. I built and drive my own electric vehicle (a converted Japanese mini truck) and those consumption figures seem completely reasonable for a vehicle of that size. I can easily see 250wh/km in aggressive stop and go driving. Regenerative braking helps but you only recover a small portion of the energy you used to accelerate in real life and that's all a bus does all day long.

Now the heater, say they're using 80% of their 324kwh pack, 259kwh, over 8 hours that's an average draw of 32.4kw from the battery. If their motor and controller are 90% efficient then you have 3240w of waste heat available continuously over that time period. Even if you could effectively capture 80% of that (likely impossible unless you insulated the motor so it didn't radiate that heat to atmosphere under the bus) that's only ~2600W of heat. I have a 1600w heater in a very small insulated cab and it's not even close to being enough when it's -20 C outside and I tend to keep the doors closed when I'm stopped. The 31 people will put out more than 2600 watts and that's not enough to keep the bus warm otherwise a heater wouldn't be needed at all. The 2600w might keep the front window clear. With something that has that many windows and that much surface area with a continuous windchill from moving through the air you need a lot of heat to keep it comfortable inside when it's -20 C or colder. The diesel heater will burn much cleaner than the diesel engine due to more complete combustion.

I'm impressed, I think it's great progress and in Quebec where 96% of the electricity is hydro this is a huge reduction in GHGs and other emissions compared to a diesel bus. Not to mention vastly reduced noise, vibration and maintenance.

JT...I agree with you that an FC range extender and a smaller battery pack could do a better job on very cold days.

The FC may no longer be necessary when 5-5-5- batteries are available?

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