TOK, Alaska — Alaska’s rugged and frigid interior can get cold as low as minus 50 degrees Fahrenheit (minus 46 degrees Celsius), but it’s not where you’d expect an electric school bus to be.
But here is bus number 50, with a cartoon horse sticker on the side, quietly traversing the snow and ice roads of Tok for about 40 miles (40 miles) each day, taking students to Canada. We pick you up at a school not far from the border.
Works fine for daily routes. However, the No. 50 cannot go on long excursions or excursions to Anchorage or Fairbanks because cold temperatures take away from the range of electric vehicle batteries.
This is a problem facing electric vehicle owners and transport stakeholders in cold climates around the world. At 20 degrees Fahrenheit (minus 7 degrees Celsius), electric cars don’t go as far as the ideal 70 degrees. Part of that is using conventional technology to keep passengers warm and drain the battery.
As a result, long journeys can be difficult in extreme cold weather. Transportation agencies like Chicago, which has committed to converting its entire fleet of buses to electricity by 2040, will have to take extraordinary steps to keep their electric buses charging on schedule.
At a time when emissions from transportation need to be drastically cut to combat climate change, some car makers and drivers are turning to electric cars, trucks and buses because batteries have less range in cold climates. We are concerned that the acceptance of there is hope Scientists are racing to perfect new battery chemistries that don’t lose energy in colder climates than current lithium-ion systems.
Also, cars with efficient heat pumps don’t lose much range in the cold.
“Having batteries in cold weather is a problem, and our climate is one of the coldest in North America,” said Stretch Blackard, owner of Tok Transportation, which contracts with local schools. It is.”
When the temperature drops to zero, his cost of running Toku’s electric bus doubles. Electricity rates in Tok are among the highest in the country.
In the coldest climates, where temperatures range from 0°C to minus 10°C (minus 18 to 23°C), electric buses cost about $1.15 per mile, while diesel buses cost 40 cents per mile, Blackard said. is. The cost of an electric bus drops to about 90 cents a mile when temperatures are warmer, but the cost makes it impractical, he says, and he won’t buy another bus.
Many private electric vehicle owners are finding it difficult to travel long distances in the winter. Many US states experience at least a few cold spells each winter, and EVs can lose anywhere from 10% to 36% of their range.
Mark Gendregske of Algiers, Michigan, says it starts to get serious when temperatures drop to 10 to 20 degrees Fahrenheit (-7 to -12 degrees Celsius). “Usually in range and charging time he sees a drop of 20% or more,” he said while charging his Kia EV6 in a shopping center parking lot near Ypsilanti, Michigan. “I go from a range of about 250 miles to about 200 miles.”
Gendregske, an engineer at an auto parts maker, said he knew the range would be short, so he planned and said the Kia EV could get you where you needed to go, even on long commutes.
However, some owners did not expect to see such a large drop in the winter. Rushit Bhimani, who lives in the northern suburbs of Detroit, says that when the weather gets colder, his Tesla Model Y’s range drops by about 30%, from a supposed 330 miles per charge he says to 230 miles. says. He said, charging just south of Ann Arbor on a trip to Chicago.
About three-quarters of this EV range loss comes from keeping passengers warm, but speed and highway driving are also factors. Some drivers wear gloves to save energy or sit in heated seats to try to use less heat so they can travel farther.
And yes, gasoline engines can lose about 15% of their range in cold weather.
Shorter range has not slowed EV adoption in Norway, where nearly 80% of new car sales last year were electric.
A recent test by the Norwegian Automobile Federation found the models to really vary. His Maxus Euniq6, which is relatively affordable, came closest to the advertised range and was named the winner. It ended up being only about 10% below its advertised range of 354 km (220 miles). The Tesla S was about 16% below the advertised range. Bottom: His BZ4X from Toyota fell short of its advertised range by nearly 36%, reaching just 323 kilometers (200 miles).
Automobile Federation’s Nils Soedal says the issue is “no problem” as long as drivers take it into account when planning their trips. “The really big problem is having enough charging stations along the road,” he said, giving better information about whether they are working properly.
Temperatures during testing ranged from freezing to -2.2 F (0 to -19 C) over mountains and along snow-covered roads. The car was driven until it ran out of juice and stopped.
Recurrent, a US company that measures the battery life of used EVs, said it conducted a study of remotely monitoring 7,000 vehicles and reached similar results to a Norwegian test.
CEO Scott Case said many EVs use resistive heating inside. Better ones use heat pumps.
Heat pumps, which can draw heat from outside air even at low temperatures, have been used for decades, but were only recently developed for automobiles, Case said. “It’s definitely what all these cars need,” he said.
Inside the battery, lithium ions flow through a liquid electrolyte to generate electricity. But when the electrolyte cools, it moves more slowly through the electrolyte and releases less energy. The same thing happens in reverse, charging slower.
Neil Dasgupta, associate professor of mechanical engineering and materials science engineering at the University of Michigan, likens it to slathering cold butter on toast. “It just makes it more tolerant at low temperatures,” Dasgupta said.
General Motors is one company working on solutions. Lawrence Ziehr, GM’s energy recovery project manager for electric vehicles, said the test will allow engineers to modify batteries and thermal management in existing vehicles and learn about future models.
Last week, GM sent a squadron of EVs from the Detroit area to Michigan’s chilly Upper Peninsula to test how cold weather affects battery range.
A GMC Hummer pickup with about 329 miles of range on a single charge traveled 315 miles to Sault Ste, despite stopping charging twice en route. Marie with about 35 miles to go. After finding a faulty charging station at a grocery store, the engineer went to a nearby hotel to get enough juice to finish the trip.
Even in college, scientists are working on changes in chemistry that could make cold losses a thing of the past.
Dasgupta of the University of Michigan says he is developing new battery designs that will allow faster ion flow and faster charging in cold climates. There are also battery chemistries such as solid rather than liquid electrolytes.
He expects improvements to extend from labs to vehicles in the next two to five years.
“There is really a global race to improve the performance of these batteries,” he said.
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