Author Topic: Tesla Model S P85 vs Chevy Volt on the dragstrip, electric touring  (Read 696 times)

protomech

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http://green.autoblog.com/2013/02/05/tesla-model-s-vs-chevy-volt-drag-race-ends-exactly-how-you-think/

Tesla Model S Performance vs Chevrolet Volt Drag Racing 1/4 Mile

I try not to read ABG comments often .. it's better for my stress levels heh. But this one caught me:
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Post by turbomonkey2k:

OK, so let's see them do a cannonball- NYC to LA. Call me crazy but something tells me the Volt beats it by DAYS. I wouldn't waste my money on either car but come one.

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Post by protomek:

2800 miles. Original Cannonball Run was LA to NYC but either way is fine.

Say the Volt hits 70 mph average moving speed. 25 mpg (spending significant time above 80 mph), premium fuel. 112 gallons premium @ $3.80/gal = $425, 1.00 metric tons of CO2 released. Total trip duration 40 hours.

The Tesla is quite a bit faster - say it hits an 80 mph average moving speed, range 200 miles. Every 100 miles (1.25 hours) it would need to stop for a 50% charge (0.5 hours), resulting in a moving average of 57 mph. 1400 kWh energy consumed @ free = $0, 0.987 metric tons of CO2 released @ national grid average (not counting solar from SC stations). Total trip duration 49 hours, 14 of which the Tesla owner is able to sleep or otherwise stretch / rest.

What's that you say? There are no Supercharger stations coast-to-coast? Fair enough, but they're coming.

The Tesla driver declares bullshit, drives to the airport (1 hour), buys a one-way ticket ($212 @ hipmunk for 2/9), touches down in LA 8 hours later. 2800 miles @ 0.18 kg CO2/mile = 0.504 metric tons CO2. Total trip duration 10 hours.

Energy consumption for both the Volt and Model S are somewhat speculative. Model S is clicking off energy at the rate of 425 Wh/mile .. around or a bit more than what the Empulse RR uses on the race track : )

***

A few days I posted on elmoto about a bike battery configuration that would give acceptable pure-EV touring capabilities:
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Posted by protomech:
Reposting (and slightly reformulating) some thoughts from the 'Build or Buy' thread.

I'd like to target total ICE replacement. Charge time tolerance will vary from person to person.. Terry @ offthegrid is probably one extreme, where the "no electric unless I can charge in 5 minutes!" crowd are another extreme. I think 15 minutes of charging per 60 minutes of riding (freeway) is a good target.

For reference:

* Tesla Model S, 15-18 minutes charging per 1 hour freeway travel (Tesla Supercharger 100 kW)
* Nissan Leaf, 30-40 minutes charging per 1 hour freeway travel (CHAdeMO 48 kW)
* 2013 Zero S ZF11.4, 63 minutes charging per 1 hour freeway travel (CHAdeMO 10 kW)
* 2013 Brammo Empulse R, 4.4 hours charging per 1 hour freeway travel (J1772 3.5 kW)
* 2012 Zero S ZF9, 13 hours charging per 1 hour freeway travel (110v 1kW)

15 minutes of charging for 60 minutes of freeway means that we must charge at 4x the power rate we discharge at (speaking generally).

Most CHAdeMO stations offer up to 48 kW of charging power, at a maximum of 100A. So if we fully utilize CHAdeMO then we can discharge no more than 12 kW. As we drive our energy consumption lower, we either reduce our charging time further, allow us to use a smaller battery pack (and charge at the same miles charged/hour rate), or allow us to use the existing battery pack and charge at a faster rate.

* 2013 Brammo Empulse R 11.6 kW @ 70 mph
* 2013 Zero S 6.4 kW @ 55 mph, 9.8 kW @ 70 mph
* 2013 Zero XU 5.8 kW @ 55 mph, 9.8 kW @ 70 mph
* Lightning faired superbike 8.4 kW @ 70 mph (120 mile range from 12 kWh)
* Monotracer enclosed-faired MTE-150 8 kW @ 75 mph

I think the Lightning target is pretty good. Perhaps it could be improved upon a bit with a feet-first riding position and a lower saddle. Enclosed front wheel, replace the mirrors with rear-pointing cameras .. handful of options.

4x 8.4 kW means we need to charge at around 34 kW, or probably 340V 100A (see also concerns in this thread about HV packs). If safe high-rate charge acceptance is a primary concern (W/kg) then energy-density (Wh/kg) may be less of a concern. I think 90-120 minutes of max-range freeway riding would be adequate - so around 13-17 kWh would be fine. Say 15 kWh as an intermediate size: 150 miles @ 55 mph, 125 miles @ 70 mph. Charge rate around 2.5C. Probably significant active cooling required for the battery.

Note that slower riding will use somewhat less energy, though an aerodynamic heavy bike will benefit less from this than an unaerodynamic light bike. Suppose 55 mph uses 100 Wh/mile or 5.5 kW .. then our charging scenario is approximately 10 minutes of charging per 60 minutes of riding.

I envision three charging scenarios:

1. Touring - quick stop to stretch, shake out legs, piss, post to internet forums. 20 minute stop, charge 20-80%, gives an additional 110 miles @ 55 mph or 95 miles @ 70 mph.

2. Dinner or movie - 30A J1772 station could charge the bike 10-90% in 2 hours.

3. Overnight - full charge would require 12+ hours on 110V.

Obviously this is contingent upon a quick-charge DC charging network (CHAdeMO or SAE J1772 DC), which exists today only as a small set of CHAdeMO equipped routes.

But suppose the charging infrastructure exists. How would we use it?

Hitting the same Model S travel speed for a coast-to-coast would probably use around 180 Wh/mile. You'd need to stop every 30 minutes (40 miles) for 12 minutes to charge on CHAdeMO, on average.. total moving average also 57 mph.

With much shorter total range (~80 miles @ near-race pace w/ 15 kWh pack) than the Model S, the bike would have to charge more frequently for shorter periods of time. Unfortunately those are less compatible with getting meaningful sleep. Touring at super-legal speeds speeds would also require many more CHAdeMO stations (every 40-60 miles along the route) than Tesla superchargers (100-150 miles) ..

Total energy used and CO2 output would be around 40-50% that of the Tesla Model S.
« Last Edit: February 06, 2013, 02:37:31 PM by protomech »
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