Sunday, 3 July 2011

Proterra Startup Will Make Electric Buses that Charge in 10 Minutes

Photo: Proterra

"Could reduce transit agencies' fuel bills by 80%"

by Michael Graham Richard, Ottawa, Canada

Buses are a great way to commute, unless maybe if you live in a rural area where population density is very low, but they can be made better by switching their drivetrains from diesel to electric. Indeed, electrification is almost ideal for buses because they have predictable routes making it easier to plan the recharging of the batteries, and they spend most of their time accelerating and decelerating in relatively low-speed traffic (the best conditions for high-torque electric motors and regenerative brakes). The main problems holding this switch to electricity back are price and how long it takes to recharge the batteries... But the startup Proterra is working on solving both of those issues.

They've just raised 30 million dollars, including 6 million from GM, to produce electric buses that use relatively small battery packs - to keep costs down - that can be juiced-up at fast-charging stations in only 10 minutes (enough to give bus drivers time to go to the bathroom and stretch their legs).
Fuel-saving technology is important to transit agencies, especially now that diesel prices are high and volatile--a gallon of diesel costs a dollar more that it did a year ago. Proterra CEO Jeff Granato says each bus will save the transit agency $600,000 in fuel costs over the 12-year life of the vehicle, plus another $70,000 to $95,000 in maintenance costs. Electricity to charge the buses costs about 18 cents per mile, compared with about $1 a mile for diesel fuel. Granato says these savings make the total cost of an electric bus comparable to that of a diesel bus over the life of the vehicle, even though the electric bus costs more up front. (The company won't say how much the buses cost, but they do, apparently, need nearly $700,000 in fuel and maintenance savings to break even with diesel buses.) ( source)

Proterra uses lithium titanate batteries that, it claims, allows them to be recharged in less than 10 minutes every few hours all day and still last eight years or more. They've also developed a special charging station that is 100% automated. The bus just goes under and a special arm overhead connects to the bus, charging the batteries are passengers get off and on the bus. Very clever.

If it works as advertised, I hope that cities around the world will pay attention and that bus fleets will be converted, over time, to this kind of technology!

Via Technology Review

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