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The Forum > Article Comments > Electric cars ARE the future > Comments

Electric cars ARE the future : Comments

By Klaas Woldring, published 4/7/2008

The search for alternative ways to fuel vehicles is in full swing now but it appears Australia is slow to get in on the act.

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I might be missing something, but electric car uses electricity, which is made from coal/nuclear, both of who the environmentalist does not like, so neither solves our problems
Posted by dovif1, Friday, 4 July 2008 8:39:05 AM
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I doubt that cars, of any kind, have any long term future. Some trucks maybe. The rest - goodbye.
Posted by michael_in_adelaide, Friday, 4 July 2008 9:48:19 AM
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dovif1: "electric car uses electricity, which is made from coal/nuclear".

What you are missing dovif1 is green power is ideal for cars. The downsides of green power are its expensive and unreliable. Green electricity is expensive compared to fossil fuels electricity, but compared to petrol its dirt cheap: its costs the equivalent of around 70c per litre for mass produced power (eg wind farms). The fact the green power can't be guaranteed at any particular time of day is irrelevant for cars. You are only using it to charge a battery, and that can happen whenever.

More remarkably its even cost effective when you do it yourself. A solar power system that generates the power to drive a car 50Km per day from your roof (ie 10KWh per day, or 3.7MWh per year) will cost you around $23,000. At 10% interest that is $2,300 / year. I took those figures from here:

http://www.actewagl.com.au/faqs/DomesticSolarGeneration.aspx

Driving 50Km per day equates to 18250Km per year. To drive that far using petrol, assuming $1.50 per litre and 10Km per litre, would cost you $2,800 per year. So this makes the most expensive way you can generate renewable electricity (home generated solar power) less expensive than petrol, at todays prices.

There are other considerations of course - the batteries are dammed expensive, electric motors are cheap (compared to petrol motors) and so on. These considerations make the real comparison more complex. In reality, without the recent commercialisation of LiFePO4 batteries electric cars wouldn't be workable. But since LiFePO4 is entering the mainstream now we can expect to see plugin hybrids available in 2010, and pure electric cars in 2012. If the price of petrol keeps going up they will be a bargain.

The article isn't really an advocacy piece for electric cars. Its more of an informative piece - telling you what the future will be like. You won't have much choice in the matter, assuming the price of fossil fuels keep rising. That applies to all fossil fuels bar coal, as they are interchangeable and their price reflects it.
Posted by rstuart, Friday, 4 July 2008 10:49:45 AM
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It all sounds very positive Klaas. But how do electric cars compare with gas-powered cars?

We have enormous natural gas reserves in Australia. Would it be quicker, cheaper and more sensible to convert our transport systems to gas power?

I think that the need to get ourselves off of our oil dependency is very urgent indeed. There is scant little room left for fuel prices to rise without really starting to affect our everyday economics, employment, inflation and the very coherence of our society.

Greenhouse gas emissions is quite frankly a distant background issue. Preventing a massive recession and societal upheaval is what really matters right now. The relative costs of alternative energy sources for transport and the speed with which we can make the conversion are the essential elements of this.
Posted by Ludwig, Friday, 4 July 2008 10:50:35 AM
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Yup they are, the potential is enormous!

http://www.teslamotors.com/index.php

shows what can be done, right now. Fact is that virtually every
MV manufacturer is rushing towards manufacturing their version,
as all can see the tremendous potential.

A huge investment is already going on to improve batteries, which
is the key. Battery scientists at MIT seem to have some real
breakthroughs on their research desks, so stay tuned.

The thing is, our present power stations already waste power in
the middle of the night, so that power can be used to charge batteries,
whilst people sleep. Then wind, solar etc, are all
suitable. In other countries, nuclear and hydropower can all
play a role too.

The thing is, electric plug-ins are not "the" answer, but "one"
answer to the problem. Certainly a major one.
Posted by Yabby, Friday, 4 July 2008 11:16:04 AM
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I would say that they are the long term future, but as pointed out above the generation of electricity produces far more CO2 than petrol.

The short term should focus on more efficient cars. This could be done with a tax on petrol. If the cost of fuel went to $5 a litre, there would be a whole lot more interest.
Posted by Democritus, Sunday, 6 July 2008 12:41:39 PM
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From my calculations it would be perfectly feasible to charge batteries for an electric car at home, especially if you had two batteries, use one & charge the other.
Off-peak power still needs to be generated and in any case quite a modest photovoltaic cell setup on your roof would be adequate.
Converting cars to LNG only extends the fossil fuel/oil problem. In any case, we should be conserving gas to make things with, not burn it up.
We already have good Australian workable designs, have a look at Trev on http://www.unisa.edu.au/solarcar/trev/
Posted by Imperial, Sunday, 6 July 2008 2:11:13 PM
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Democritus: "generation of electricity produces far more CO2 than petrol"

Assuming you mean that when used to push a car, electricity produces far more CO2 than petrol: rubbish. In the worst case scenario for electricity (coal generated, petrol car), they are about the same.

Assuming it takes 25 KW to push a car at 100 Km/h [1], and assuming generating 1 KW/h of electricity produces 1Kg of CO2 [2], then driving the electric car 100 Km produces 25 Kg of CO2.

Assuming 10 Km/litre, and burning 1 litre of petrol produces 2.3 Kg of CO2 [3], the CO2 produced driving a petrol car is 23 Kg.

A coal fired generator runs at around 60% efficiency, the internal combustion engine at around 15%. However coal gets all of its energy from C + O2 --> CO2 (ie CO2 production), whereas hydrocarbons also gets some from 2 H2 + O2 --> 2 H2O (ie water production).

[1] The normal figure given is 20 KW. I used the more conservative figure of 25 KW as when in a hybrid Lexus driving along at 100 Km/h with air-conditioning on, it showed that figure on its dashboard.

[2] Figures on the web for CO2 per KWh of electricity produced from coal vary from around .4 Kg to 1Kg. I choose the more conservative figure. I suspect the difference is between generated and delivered.
http://www.sedo.energy.wa.gov.au/pages/heat_run.asp

[3] http://www.environment.tas.gov.au/anw_aq_rlap_motor_vehicle_emissions.html
Posted by rstuart, Sunday, 6 July 2008 2:42:56 PM
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Rstuart,

Before you rubbish what I am saying please at least make the effort to read the links you have provided.

Using the information I got from your websites I calculate that a small car using petrol at 7 litres per 100 km (my small car does better than this) would generate 16kg of CO2

A car using 20kW at 100kmph would use 20kwhr. Now the average kWhr generates 0.99 kg of CO2 according to the website, so with a reasonable charging/discharge efficiency of about 80%, an electric car would generate 25kg of CO2.

Your errors were assuming 100% charging efficiency, coal generation is about 35% efficient for black coal and about 25% for brown coal.

As the majority of electricity is generated from brown coal, nest from black coal, and a small swing load from gas co gen plants (60% efficiency) the 1kg of CO2 per kWhr is accurate.

Thus electricity generation has to improve by at least 35% for electricity powered cars to be even considered. This does not take into account the energy and cost of making and disposing of the batteries and the inconvenience of the short range.

Next time please check your calculation before you put your foot in it again.
Posted by Democritus, Sunday, 6 July 2008 9:02:45 PM
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Demo, the URl below contains some figures for the Tesla. Perhaps
the company has it wrong. Perhaps you could point out where.

http://www.teslamotors.com/efficiency/well_to_wheel.php

.
Posted by Yabby, Sunday, 6 July 2008 10:43:23 PM
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One more interesting suggestion that I have seen is electrified roadways.
A number of methods was proposed but the basic idea was that you drive
your electric car to the nearest main road and connect to the roadway
and use the roadway power from there on.

As a matter of interest there is an electric car parking and charging
point in the shopping centre at Dural in NSW.

Democritus, I think you are wrong, the efficiency in power stations and
the transmission system is such that there is less CO2 generated per km
than if you burn petrol in the very inefficient internal combustion
engine.

The suggestion of using solar cells to charge electric cars does
not have a technical flaw but a logical flaw.
The commuter drives home in late afternoon and the sun has gone down
and in the morning he is off before the sun is up for long enough.
You could charge batteries during the day and charge from them at
night but the losses involved would make it a no goer.
Posted by Bazz, Monday, 7 July 2008 11:23:05 AM
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Democritus: "at least make the effort to read the links you have provided"

I did. And I just did again. What did I miss?

Democritus: "a small car is ... 25 Kg CO2 vs 16 Kg CO2"

The words in your original post I took issue with were "far more". My 25 Kg CO2 (electric) vs 23 Kg (electric) was intended to show they were at best an exaggeration. And your right I didn't take into account charging efficiency, but then I was being conservative in other areas. Then you come up with some figure of 25 Kg CO2 vs 16 Kg. If this was meant to be somehow representative of the state of play now - well its another exaggeration.

To avoid playing games with figures lets just look at the figures at they stand. Australian car fuel efficiency hasn't changed much in the past 10 years. It hovers around 8.7 km/litre [1]. So using 80% charging efficiency we get using my conservative figures 31 Kg CO2 (electric) for the 100 Km trip vs 26.5 Kg CO2 (petrol) for the same trip - for an average Australia car. That is a 14% difference - probably within the noise margin of these calculations.

Yes, in the future things may change. Car sizes will go down, but electricity generation will almost certainly become greener. For example a modern coal fired power station operates at 42% efficiency [2][3] - quite an improvement from the 35% you quote. 14% of our electricity comes from gas which produces 1/2 the CO2 of black coal. Renewables, from which we get around 8% of our electricity now, produce none. [4]

In view of all that, I still think your claim that electric cars produce "far more" CO2 now, or will do so in the future is, well, rubbish.

[1] http://www.ptua.org.au/myths/efficient.shtml
[2] http://en.wikipedia.org/wiki/Rankine_cycle
[3] OK, so the 60% figure I gave was just plain wrong - got myself confused with the theoretical Carnot efficiency.
[4] http://velocity.ansto.gov.au/velocity/ans0011/article_03.asp
Posted by rstuart, Monday, 7 July 2008 11:35:06 AM
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Bazz: "You could charge batteries during the day and charge from them at night but the losses involved would make it a no goer."

Perhaps so - I don't know what the efficiency of the typical lead battery used in a house setup is. Certainly other battery chemistry's aren't so bad. This mob [1] claims their LiFePO4 batteries are 95% efficient, but people who have measured other brands of LiFePO4 seem to end up around the 90% figure.

However, there are other solutions - like getting paid to put your electricity into the grid, and then paying to charge from the grid where you park your car for the day. Or making the batteries part of the house system and rotating them through the car.

The point I was trying to make is that once you store the energy the unreliability of renewable energy becomes amenable to a lot of solutions and so is a lot less of an issue. The problem always was finding cost effective way to store the energy in the first place.

[1] http://www.edealsbargains.com.au/page1.php
Posted by rstuart, Monday, 7 July 2008 3:12:14 PM
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rstuart,
A long, long time ago I attempted to measure charge/discharge
efficiency of lead acid batteries. I found it very difficult to do.
The specific gravity did not seem to track the electrical indications
too well. It was difficult to charge from a certain point and then
discharge to the same point. From memory I think I got figures between
50% and 80% before I gave up.
However the solar feedin and then charge at night would be pretty good.

Changing the batteries would be very cumbersome (and heavy).
Most electric cars I have seen distribute the batteries for and aft to
even out the load on the suspension and this would make battery
changing even more complicated.

No, solar cells feeding the grid during the day and charging from
the mains at night is the way to go.
Posted by Bazz, Tuesday, 8 July 2008 8:07:15 AM
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Rstuart,

Your figure of 42% efficiency is possible using the latest hitech high temperature metals, using ideal coal (low ash top grade, not high ash or brown coal) which have only been possible to build in the last 10 years at great expense.

The reality is that the average efficiency world wide is 31% as quoted by:

http://www.euractiv.com/en/energy/analysis-efficiency-coal-fired-power-stations-evolution-prospects/article-154672

"Nowadays, with a world average efficiency of around 31%, coal-fired power stations is said to compare favorably with the upper range of any other power generation technology."

And considering that 31% is considered good, 42% is a bit fanciful.

Personally I drive a small car that get 6.5l/100km and our big car is a Renault 4x4 that gets 8.5 litres /km. The fact that Australians love their big cars with V8 engines would suggest that these cars use a little more that 20kW (cited by your hybrid car) and that using this figure is distorting the facts.

Secondly charging efficiencies on batteries including the charger losses (15%) are about 65% at best.

The figure I get is that the average car needs about 30kWhr per 100km (including battery losses delivering the power)

My reckoning is that a reasonably efficient family car (8.7l/100km) would generate 26.5kg CO2 and the Equivalent electric car would generate closer to 43kg of CO2.

While power generation is getting greener, it has to go a long way before the electric cars can claim to be greener.

Also the proposal to charge a spare battery during the day and changing batteries would be an extraordinary feat considering the size of batteries required for an electric only car.
Posted by Shadow Minister, Tuesday, 8 July 2008 8:23:50 AM
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Shadow Minister: "considering that 31% is considered good"

You sure chose the wrong link to illustrate your point - I wish I used it originally. Firstly 31% is the average for coal-fired power stations now. How can the average be considered good? The link said 31% was good compared other technologies, such as an internal combustion engine. Secondly the 42% figure I quoted was meant to show that we can expect improvements as time goes on. Compared to the conclusions in your link I was being conservative:

"Energie-Fakten considers it feasible to have 55% efficiency available for the necessary replacement and addition of coal-fired power capacity."

Shadow Minister: "30kWhr per 100km"

You and I will have to differ here. I will go with what the power meter on the Lexus says. The hybrid Lexus isn't a small or light car - its specs say the engines can deliver a combined total 360 KW. It has air-conditioning and every other gadget know to man, and they were all switched on. As I said, it the power meter showed it was drawing 25 KW and that is the figure I used in my calculations. This is more than the 20 KW figure often quoted as size of electrical motor required to push a vehicle at 100 Km/h, but the 25 KW is from a real, live family sedan going down a real live Queensland road at 100 Km/h, which is why I used it.

As for "battery losses" - as I said earlier, LiFePO4 has a cycle efficiency of 90%, or perhaps better. My calculations used 80%.

Democritus was simply wrong when he said electric cars produce "far more" CO2. "More" would of been defensible, on the understanding that it will become "less" or possibly even "far less" as electricity generation becomes greener. Call me pedantic, but I see take exception when I see crap like that come from someone that looks to have a strong technical background. I expect better from my peers - and thus the strong words.
Posted by rstuart, Tuesday, 8 July 2008 11:49:05 AM
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