Tesla Motors - 100% Electric Vehicle

[DGthe3]

Originally Posted by HeHasReturned

A. It's two years away from production

B. They've managed to bring the recharge time down to 45 minutes. Won't be long until they further narrow it down in future electric cars. Not to mention that a 160 mile range is way more than people drive on average daily, so they can always recharge it overnight. Only time you'll have to worry is on a long trip somewhere. That also isn't a huge problem. If you drive 300 miles straight, chances are you're willing to take a 30 minute rest stop anyways.

Thats a recharge in the same way using a jerry can when you're out of gas is a refill. Those batteries will be at least 40 kWh capacity. So, to fully recharge them in 45 minutes would require it to be delivered at a rate of over 50 kW/h. Thats 10x what a house is normally using. I don't think the power lines to a house are capable of delivery power at that rate.

[alrox]

Originally Posted by Brokinarrow

Funny, wasn't the same thing said about the first automobiles?

You can always tell the correct people from the incorrect people during a discussion. The correct person states facts and the incorrect person tries to cover his ignorance by asking witty questions.

[Captain Awesome]

Basically when you break down the numbers electric power generation is about 75% efficent. Transmission is about 95% efficient. Battery charge is about 80% efficient. Discharge is about 90% efficient.

Internal combustion engines are about 18% efficient.

If you do the math, you see that it's almost exactly a wash. You lose 82% of your energy in a combusion engine and lose 82% of your energy in an electric car.

Drilling and refining costs energy but mining coal and transporting it also costs money, etc.

What it boils down to is that most of the losses in these processes are losses caused by some portion of the energy being converted to heat.

However, in the gasoline powered car the heat is lost locally and can be captured and put to use in the climate control system. In the electric car the heat is lost in generation, transmittion, and storage of the energy. Only a miniscule fraction is lost in the use of the car and that is difficult to capture and reuse.

In other words, the majority of drivers use heat at some point, and since it is free with the internal combustion engine vehicle, they are actually saving energy due to the more efficient recycling of waste heat in an otherwise fairly equal system with the electric car.

[DGthe3]

Originally Posted by Captain Awesome

Basically when you break down the numbers electric power generation is about 75% efficent. Transmission is about 95% efficient. Battery charge is about 80% efficient. Discharge is about 90% efficient.

Internal combustion engines are about 18% efficient.

If you do the math, you see that it's almost exactly a wash. You lose 82% of your energy in a combusion engine and lose 82% of your energy in an electric car.

Drilling and refining costs energy but mining coal and transporting it also costs money, etc.

What it boils down to is that most of the losses in these processes are losses caused by some portion of the energy being converted to heat.

However, in the gasoline powered car the heat is lost locally and can be captured and put to use in the climate control system. In the electric car the heat is lost in generation, transmittion, and storage of the energy. Only a miniscule fraction is lost in the use of the car and that is difficult to capture and reuse.

In other words, the majority of drivers use heat at some point, and since it is free with the internal combustion engine vehicle, they are actually saving energy due to the more efficient recycling of waste heat in an otherwise fairly equal system with the electric car.

Batteries heat up too. So much so that GM had to develop a thermal management system for the battery packs of the Volt. Not sure what Tesla is doing with their laptop batteries.

[BigRigMike]

Originally Posted by Captain Awesome

Basically when you break down the numbers electric power generation is about 75% efficent. Transmission is about 95% efficient. Battery charge is about 80% efficient. Discharge is about 90% efficient.

Internal combustion engines are about 18% efficient.

If you do the math, you see that it's almost exactly a wash. You lose 82% of your energy in a combusion engine and lose 82% of your energy in an electric car.

Using your numbers electric power is 51% efficient and internal combustion is 18% efficient. Sounds pretty good to me.

If you assume you start with 1kw equivalent of coal
Power generation 1 kw * .75 = .75 kw
Transmission .75 kw * .95 = .7125 kW
Battery Charge .7125 kW *.8 = .57 kW
Discharge .57 kW *.9 = .51 kW

[LostInMoscow]

Originally Posted by Nycteus

You're correct concerning the fact that magnetic motors have a huge benefit at 0 RPM and deteriorated benefit at higher RPM's. Here's a power and torque chart comparing a standard high output 6 cylinder vs. a magnetic motor:




This was taken from: http://www.teslamotors.com/performan...and_torque.php

I'm an electrical engineer also. Apparently there are too many of us?! Anyway, a series wound DC motor has infinite torque at 0 RPM, a whole lot of torque at low RPMs and then it loses torque quickly at higher RPMs. However, you don't have to use series wound motors or for that matter even DC motors either. Ford made an electric car with an inverter a few years ago that had AC motors. You can also wind a DC motor so that the torque curve is what you want it to be more or less. You can get good torque at higher RPMs if you do it right. It's sort of an art.

Regarding recharging, I envision a future where you have a little trailer attached to the back of your vehicle that holds the batteries. You stop at a little roadside (we'll call it a filling station) when you have a low charge, and you just swap out your trailer for a freshly charged one. That's just about the most practical way to do it. Will it happen in our lifetime? Probably not, but I think it's the only way to practically use a fully electric car as a replacement for the cars of today. I like fuel cells myself. Hydrogen is a great fuel if it doesn't explode on you.

[alrox]

Originally Posted by LostInMoscow

Regarding recharging, I envision a future where you have a little trailer attached to the back of your vehicle that holds the batteries. You stop at a little roadside (we'll call it a filling station) when you have a low charge, and you just swap out your trailer for a freshly charged one.

Practically impossible. You would get stuck with someone elses 'bad' battery pack and just trade it in at the next station, always leaving someone holding the bad one.

Spending 5 minutes and putting a very abundant fuel, gasoline, into your car very easily sounds like a much more viable solution for the billions of common people on earth.

[Brokinarrow]

Originally Posted by alrox

You can always tell the correct people from the incorrect people during a discussion. The correct person states facts and the incorrect person tries to cover his ignorance by asking witty questions.

And the incorrect people refuse to answer questions they know would make them look bad? Ok, here are some FACTS for you:
When the automobile first came out, it was a toy for the rich and famous.
There was no gasoline infrastructure until oil was discovered in the US, thus hindering widespread adoption of the automobile (on top of the high asking price among other things).
It took some major technological advances, along with some ingenuity on the part of one Henry T. Ford, to make the automobile cheap enough for the general public to afford, along with making it reliable enough so it wouldn't break down every other week. The first auto owners usually had their own mechanics living on site, as the early contraptions were always breaking down. Once everyone started buying cars, gas stations popped up everywhere.

Now we move from fact, to speculation (as that's all one can do in regards to the future):

These same exact things can be said of the electric vehicle. Until a cheap source of clean energy is found and made easily available to the public, it will be difficult at best to develop an infrastructure. Once that is in place, along with the necessary technological advances to further improve charging times and battery capacity, electric vehicles will begin to take over and you'll see charging stations along side of gas stations.

Originally Posted by alrox

Practically impossible. You would get stuck with someone elses 'bad' battery pack and just trade it in at the next station, always leaving someone holding the bad one.

Spending 5 minutes and putting a very abundant fuel, gasoline, into your car very easily sounds like a much more viable solution for the billions of common people on earth.

You seriously underestimate human ingenuity. It's only a matter of time till someone designs a better battery.

[alrox]

Originally Posted by Brokinarrow

And the incorrect people refuse to answer questions they know would make them look bad? Ok, here are some FACTS for you:
When the automobile first came out, it was a toy for the rich and famous.
There was no gasoline infrastructure until oil was discovered in the US, thus hindering widespread adoption of the automobile (on top of the high asking price among other things).
It took some major technological advances, along with some ingenuity on the part of one Henry T. Ford, to make the automobile cheap enough for the general public to afford, along with making it reliable enough so it wouldn't break down every other week. The first auto owners usually had their own mechanics living on site, as the early contraptions were always breaking down. Once everyone started buying cars, gas stations popped up everywhere.

120 years ago there was no worldwide infrastructure to support individual movement in their personal transportation vehicles. The investment into gasoline was made because it was deemed the best fuel and it cost a lot to do.

Hundreds of trillions of dollars have been spent on our current gasoline infrastructure. Untold trillions more would be spent to implement an electric grid to support the same amount of energy that gasoline does. If you hadn't noticed lately, the world is broke and has no money. The cost/performance ratio of implementing this is unfeasible.

Originally Posted by Brokinarrow

You seriously underestimate human ingenuity. It's only a matter of time till someone designs a better battery.

I have no doubt a better battery will be made, but batteries will always be unfeasible for mass individual transportation consumption.

[Brokinarrow]

Originally Posted by alrox

Practically impossible. You would get stuck with someone elses 'bad' battery pack and just trade it in at the next station, always leaving someone holding the bad one.

Spending 5 minutes and putting a very abundant fuel, gasoline, into your car very easily sounds like a much more viable solution for the billions of common people on earth.

Originally Posted by alrox

120 years ago there was no worldwide infrastructure to support individual movement in their personal transportation vehicles. The investment into gasoline was made because it was deemed the best fuel and it cost a lot to do.

Hundreds of trillions of dollars have been spent on our current gasoline infrastructure. Untold trillions more would be spent to implement an electric grid to support the same amount of energy that gasoline does. If you hadn't noticed lately, the world is broke and has no money. The cost/performance ratio of implementing this is unfeasible.



I have no doubt a better battery will be made, but batteries will always be unfeasible for mass individual transportation consumption.

Oh really, I didn't realize the world had a finite amount of money? Please do explain this new world currency that must magically disappear after it's spent, since the world is running out of it.

And with your second highlighted statement, you again are putting limits on what technological advancements can be made.
For someone stating that 'correct people state facts', I sure don't see a lot of them in your arguments.

[SuperFly03]

I thought I would throw my 2 cents in here.

At the end of the day a 160 mile range is perfectly acceptable for a significant majority of Americans on a day to day basis (think 80%+). Now, the obvious draw back is long road trips would be a hassle but if this were a second car or instead you rented a car for trips then you would be good to go. On a 300 mile range battery pack (granted that's probably another 15k, or so idk) then you should be able to work with it as a primary vehicle save trips from FL to TX. It has it's drawbacks compared to gas cars but at the same time it is very inexpensive to charge and at the same time eliminates emissions and actually makes the world a bit quieter (not something some of us Camaro owners may like *cough* loudmouth exhaust *cough*). It may take 4-5 years to break even at current gas prices (assuming a Model S vs a 40k sedan alternative) but then again there is more to owning an EV car than saving money. It could also take 8-10 years if you compare against a 30k sedan... that is a decision and calculation that has to be made on an individual basis.

Who cares if the power source isn't 100% clean? The idea here isn't to have this awesome alternative which everyone is happy with on day 0 or is a magic bullet to cure every world problem. Instead it is a step in the right direction such that we can ween ourselves off of petroleum which everyone, without exception, should agree has a finite supply and an increasing marginal cost. So what if this isn't a perfect EV vehicle. It is one of the first ones that doesn't completely suck *cough* Nissan Leaf *cough*. Are there better alternatives in terms of value, range, etc? Yes, 100% but someone has to be the early adopter.

I'm actually considering it as a second vehicle (addition to my 5th Gen in my garage) because on an average day I drive in the neighborhood of 60-80 miles total and I need a 4 door sedan. The allure of a $4 fill up, even if it takes charging overnight, is appealing. Additionally, you can fix the cost of your electricity via fixed rate contracts with the power company which adds a certain stability to a family's expense level. With oil you are subject to the whims of investors and OPEC. A study done in 08/09 (forget which) found that more than 50% of all positions held in oil were speculative and held by people who never intended on taking delivery of the oil they purchased. As we have seen there can be significant volatility in the price of gasoline which isn't going to go away. At least with fixed rate electric contracts you don't get sticker shock. You know going in what it will cost you for a year or two or whatever term you choose. Then you visit your contract again when its time to renew but again you know the cost going in.

Do I think it is ready to replace gas engines? Nope, not yet. However, Tesla (and to an extent Nissan and Chevy) have made EV vehicles and brought them to market that can be purchased (Model S in 2012). That is reality and the first step. You have to get something to market that can actually be purchased if things are ever going to move forward.

You can argue the pros and cons and the value aspects all day and you'd be right to do so but regardless. This is progress.

[Captain Awesome]

Originally Posted by BigRigMike

Using your numbers electric power is 51% efficient and internal combustion is 18% efficient. Sounds pretty good to me.

If you assume you start with 1kw equivalent of coal
Power generation 1 kw * .75 = .75 kw
Transmission .75 kw * .95 = .7125 kW
Battery Charge .7125 kW *.8 = .57 kW
Discharge .57 kW *.9 = .51 kW

Actually I made a typo in the original post.

It's a long story but I had typed in a much more detailed breakdown of the numbers right down to drag losses and accessory losses I got from the EPA site. I went to submit it and the site kicked me back to the "login" screen and when I logged in the post was lost and hitting "back" didn't get me back to the post I had typed in over an hour.

The actual numbers I had gotten for power generation was roughly 25% EFFICIENT. The site I had googled said 75% loss and I mistakenly flipped it to 75% efficient. The real number is that electrical power generation is 75% Loss... or 25% efficient.

The most efficient source of power generation is hydroelectric which only has about 10% losses (90% efficient), but since only about 10% of electricity in the USA comes from hydro plants, the impact is not that great. Most people get their power from horribly inefficient sources like coal burning and whatnot.

My original calculations put electricity at 18.5% efficient for cars and the number I got from the EPA for Gas was 18.2% efficent. A wash.

Pure Electric cars just don't cut it.

[Captain Awesome]

Originally Posted by DGthe3

Batteries heat up too. So much so that GM had to develop a thermal management system for the battery packs of the Volt. Not sure what Tesla is doing with their laptop batteries.

According to my research, batteries heat up on CHARGE more than on discharge (20% loss on charge and 10% loss on discharge).

Since the Volt uses a gas engine to charge the battery, the thermal management system is there mostly for charging the battery. On a "pure electric" like the volt, there's half as much energy lost to heat because it only discharges the battery while running.

The heat generated while charging the Tesla is considered waste because it happens while the car is sitting in your driveway not doing anything useful.

[Nycteus]

Originally Posted by SuperFly03

This is progress.

Exactly Correct.