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Shenzhen Electrifies Entire Public Transit Bus Fleet

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21–30 of 77 posts

Re: Shenzhen Electrifies Entire Public Transit Bus Fleet

#21
post #14

The low-speed maglevs being built in China seem a little more interesting. https://www.yicaiglobal.com/news/construction-low-speed-magl... Getting people from point A to B faster on mass transit will get them out of cars and cabs.

The Changsha airport-train station maglev link is quite convenient, and ya, definitely saves a cab trip.

Re: Shenzhen Electrifies Entire Public Transit Bus Fleet

#23
post #12

Earlier quoted context omitted.

Coal provided electricity to power electric powers ends up _still_ being cleaner than ICEs, which are just about the worst in efficiency or cleanliness as you can get.

Coal releases lead, radon, and other toxic pollutants into the environment. And you haven't supported the assertion that coal-powered EVs emit less CO2, and it contradicts what I've generally heard elsewhere.

You have no idea if coal, gas, or nuclear is used. You just made a guess that they use more coal?

According to Wikipedia there are two gas fired plants in Shenzhen: https://en.wikipedia.org/wiki/List_of_major_power_stations_i...

Re: Shenzhen Electrifies Entire Public Transit Bus Fleet

#24
post #12

Earlier quoted context omitted.

Coal releases lead, radon, and other toxic pollutants into the environment. And you haven't supported the assertion that coal-powered EVs emit less CO2, and it contradicts what I've generally heard elsewhere.

Do the math instead of listening to people who resist change. You are right about the extra stuff that comes with coal power, but you will find with a good modern coal plant, transmission losses, and battery/electric motor loss still puts less CO2 in the air that gasoline cars per mile travelled.

https://www.citylab.com/environment/2015/06/where-electric-v...

Re: Shenzhen Electrifies Entire Public Transit Bus Fleet

#25

Living in Shenzhen, it feels like probably 80% of the taxis are electric already. Due to government subsidy the blue electric BYD cabs are more spacious, cheaper (no 2元 fuel surcharge), newer and cleaner than the older red cabs, which are generally clunky dirty squashed VWs. However, the drivers pay more to buy them even with subsidy, and you need a conventional ICE vehicle to get out to the factories in Dongguan, or…

Shenzen / Hong Kong will be the next Silicon Valley.

Re: Shenzhen Electrifies Entire Public Transit Bus Fleet

#26
post #15

This is really impressive, I've been very skeptical of heavy payload capability and range for electric vehicles until now. Will be interesting to see how well they perform, how the charging infrastructure works and battery life

> very skeptical of heavy payload capability and range for electric vehicles heavy usually means "not that fast" - so less of the speed-squared drug (at 25miles/hour i remember some guys did double the range, like 400miles+, on a Tesla S) and also the weight of the battery becomes less of a factor on the background of the whole vehicle and cargo weight.

Two things to note about heavy vehicles.

Often the power plant size is less than you would expect. Partly because drag is proportional to frontal area and goes up with the square of the vehicle size. While load is proportional to volume, goes up with the cube. That points to passenger cars being the worst case scenario, not trucks and buses.

Second, batteries are a tech that just scales lineally. Double the capacity of a battery pack? Double the weight, volume, and cost. Consider with a bus the metric isn't battery size per bus, it's battery size per passenger.

Add for electrified heavy equipment like tractors, etc. The extra weight of the battery is a bonus not a negative. You need weight to get traction not HP.

Re: Shenzhen Electrifies Entire Public Transit Bus Fleet

#27

That will be Tesla's next big announcement

Once they have the truck platform, won't it be easy to swap out the trailer for a passenger cabin?

I doubt it - buses typically have the driver in the same compartment as the passengers, and are much lower to the ground than the trailer.

Re: Shenzhen Electrifies Entire Public Transit Bus Fleet

#28
post #17

Talk about all the buses you want. What I really really want to hear about is the chargers that make it possible. Give me maximum MW rates and rates for how much each station can crank out in total.

The article says, "The city has built 8,000 charge points at 510 bus charging stations in order to be able to charge roughly half the fleet at any given time"

Re: Shenzhen Electrifies Entire Public Transit Bus Fleet

#29
post #26
post #15

Earlier quoted context omitted.

> very skeptical of heavy payload capability and range for electric vehicles heavy usually means "not that fast" - so less of the speed-squared drug (at 25miles/hour i remember some guys did double the range, like 400miles+, on a Tesla S) and also the weight of the battery becomes less of a factor on the background of the whole vehicle and cargo weight.

Two things to note about heavy vehicles. Often the power plant size is less than you would expect. Partly because drag is proportional to frontal area and goes up with the square of the vehicle size. While load is proportional to volume, goes up with the cube. That points to passenger cars being the worst case scenario, not trucks and buses. Second, batteries are a tech that just scales lineally. Double the capacity…

Buses don't need huge batteries for their size. A typical city bus goes only about 100 miles a day, they do a ton of regenerative breaking, and they can charge at stops and also they tend to sit in the terminal several times a day while the driver takes a break after each circuit.

Electric trash collection trucks are even better. That's because they do so much regenerative breaking.

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