Last summer, the Mayor of London proudly unveiled plans to test a fleet of double-decker electric buses to ply the tourist-friendly Route 16, and things must have gone swimmingly because just last week a fleet of five of the hulking EVs was announced for Route 98. Aside from pleasing commuters and tourists alike with a quieter ride, the zero-emission buses — from China’s BYD — will help to calm a pollution hotspot in the city.
The new buses are of course tinted in London’s traditional bright red, but we’re especially interested in what’s under the hood: BYD’s proprietary iron-phosphate EV batteries.
It’s a Heavy Duty EV World…
CleanTechnica has been keeping an eye on BYD, and the London double-decker EV project is just the latest in a long string of cleantech areas of interest for the company, including both passenger and commuter-scale EVs, EV charging stations, solar energy, and energy storage.
Not too long ago, the electric bus sector was considered a challenge, but BYD is among a number of companies that have figured it out:
The buses are equipped with BYD-designed and built Iron-Phosphate batteries, delivering 345 kWh of power that come with a Industry-benchmark 12 year battery warranty, the longest electric battery warranty available. The batteries can power the bus for over 24 hours and up to 190 miles of typical urban driving on the service routes with a single daily recharging requiring only four hours.
As for power, each of the five new buses tops 33 feet long and carries a total of 81 passengers. Add climate control and that’s a heavy load, but based on the success of last year’s demonstration, it looks like electric double-decker buses have what it takes to cope with London traffic.
In addition to battery range, power, and relatively quick turnaround on charging, one key to success is the use of regenerative braking as a range extender. That technology is a perfect match for the frequent starts and stops along urban bus routes.
To gild the EV lily, London’s Deputy Mayor of Environment and Energy, Matthew Pencharz, noted that maintenance and operating costs are lower — as is typical of EV technology.
It’s getting hard to remember a time when EV critics routinely claimed that electric drive could not compete with diesel fuel for buses and other heavy-duty vehicles, but those days are long gone.
The Iron-Phosphate EV Battery
As for the iron-phosphate EV battery, the BYD website is a bit coy on the details, but you can get an idea of the forces at work by taking a look at the US Energy Department’s interest in the technology.
The agency’s Argonne National Laboratory has been noodling around with lithium-iron phosphate (LiFePO4) energy storage, and in 2013 it issued the results of its findings, noting these benefits:
A simple, straightforward process that uses low-cost precursors and does not involve high energy consumption
Increased energy density and long cycle lifetime
No carbon coating is needed, which saves a processing step and reduces costs by 50%
Materials can be added at low cost without changing current scalable cathode manufacturing processes
The National Renewable Energy Laboratory offered this snapshot of the technology for EV batteries back in 2011:
Aside from performance, the materials issue is critical from a supply chain and airborne pollutants point of view. The Energy Department, for example, foresees “strained” supplies of other emerging EV battery materials — namely, nickel and cobalt. The agency has also pointed out that lifecycle emissions of sulfur dioxide are higher for batteries that use nickel or cobalt.
Images: top via businesswire.com, bottom via NREL.
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