<Sixth Annual ASPO Conference – Cork, Ireland The Oil Drum DrumBeat: September 16, 2007>

147 comments on A Tale of Two Speeches--OPEC's Demand Side Fear Is Very Real

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Pitt the Elder on September 15, 2007 - 4:48pm Permalink | Subthread | Parent | Comments top

Even with losses for electricity transmission, rectification etc, this seems like a good deal compared with an average 20% efficient internal combustion engine. Possibly 10-20% better than a prius (36% efficient?), even after losses.

According to this, an all-electric car is about twice as efficient as a Prius, assuming a 60% efficient modern cogenerating electric plant, which would make it somewhere around 100mpg based on well-to-wheel energy consumption. One would expect a plug-in hybrid to be fairly similar, at least when running solely on electric.

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JWhitland on September 15, 2007 - 8:00pm Permalink | Subthread | Parent | Comments top

Thanks. Note that the "double" is for natural gas fired plants. Still, even coal-generated electricity would be more efficient then gas, if not as convenient.

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Rethin on September 15, 2007 - 8:55pm Permalink | Subthread | Parent | Comments top

I worked this out a while ago, and keep reposting it as it keeps coming up. Turns out its really not the silver bullet some claim.

Lets use Tesla's numbers here
http://www.teslamotors.com/learn_more/energy_efficiency.php?js_enabled=1

If we use NG as an electricity source we get a well to station (I assume your outlet) efficiency of 52.5% The Tesla has a vehicle efficiency of 2.18Km/MJ so we get an well to wheel efficiency of 1.14km/MJ.

Crude oil has a well to station efficiency of 81.7%, A prius has a vehicle efficiency of .68 giving us a well to wheell efficiency of .556km/MJ.

But the Tesla number comes from using NG as an electricity source. NG makes up only a tiny fraction of our electricity sources (from the chart posted below) and is used mainly for peak generation. If we use the average effeciency for a thermal electric plant, 31% we get a much different number for the Tesla.

The average thermal electric plant has a well to station efficiency of 31% The Tesla has a vehicle efficiency of 2.18Km/MJ so we get an well to wheel efficiency of .67km/MJ.

.67 for the Tesla is only slightly higher than the Prius at .556.

So if I did that correctly (and please correct me if I didn't) it comes down to how you generate the electricity.
So I'll put the question to you, how do you propose to charge all these EVs (and I guess PHEVs as well)?

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robert2734 on September 15, 2007 - 10:05pm Permalink | Subthread | Parent | Comments top

California gets half our electricity from natural gas. Assuming NG electricity is not so valid for the USA as a whole but maybe Tesla plans to market in silicon valley. For now.

Anyways the efficiency of gasoline powered cars don't matter if there is no gasoline.

I plan to charge all these EVs during the day with solar panels. How do you plan to fuel all those hybrids?

RobertInSantaBarbara

I haven`t escaped from reality. I have a daypass.

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Rethin on September 16, 2007 - 4:25am Permalink | Subthread | Parent | Comments top

Anyways the efficiency of gasoline powered cars don't matter if there is no gasoline.

True.

I plan to charge all these EVs during the day with solar panels. How do you plan to fuel all those hybrids?

Most vehicle use is during the day. Its tough to charge your EV during the day.

Most schemes I read plan to charge these EVs during the night on wasted capacity (coal plants don't shut down quickly so often are left wasting power overnight). And that was what I originally wrote the above for.

Solar has severe drawbacks for charging at night.
If I got to make the decision I'd go for nuke and wind.

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robert2734 on September 18, 2007 - 7:30am Permalink | Subthread | Parent | Comments top

Most vehicles are driven to work during the day and left in the company parking lot for eight hours. Google already has solar powered recharging stations for employees with PHEVs.

RobertInSantaBarbara

I haven`t escaped from reality. I have a daypass.

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Nick on September 18, 2007 - 11:05am Permalink | Subthread | Parent | Comments top

robert2734's comment is good. The thing is, the average vehicle is parked 23 hours of the day, and 90% of the time it's offstreet.

It's just a question of putting a connection at that parking space. It's done in Canada & Minnesota at parking meters & garages for engine pre-heating.

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Pitt the Elder on September 15, 2007 - 11:15pm Permalink | Subthread | Parent | Comments top

Mostly true, but mostly beside the point.

When discussing massive numbers of electric cars, the typical concern is the additional generating capacity that would have to be added to power them. When adding new generating capacity, what matters is the efficiency of new generating plants, not the average efficiency of the decades-old ones that make up the grid now. Accordingly, the relevant efficiencies to consider really are the higher ones.

Moreover, electric vehicles are qualitatively better than gas-powered vehicles in the sense that they're much less constrained by fuel type. Peak oil is often described as not an energy crisis but a liquid fuels crisis; without that reliance on liquid fuels, electric vehicles are fundamentally different in peak oil terms.

So I'll put the question to you, how do you propose to charge all these EVs (and I guess PHEVs as well)?

With whatever's convenient, since they're not at all picky about fuel type.

One of the benefits of wide-spread plug-in vehicles would be a wide-spread network of batteries hooked up to the grid. Those would be exceptionally useful for smoothing out wind and solar PV generation more cheaply and efficiently than by adding pumped storage.

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Rethin on September 16, 2007 - 4:26am Permalink | Subthread | Parent | Comments top

No disagreement here. Like I said, it all comes down to how you charge these EVs.

We are going to have to parallel deployment of large ev fleets with huge investments in elec generation and grid capacity.

My fear is this is going to come too little and too late.

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Nick on September 16, 2007 - 5:39pm Permalink | Subthread | Parent | Comments top

"We are going to have to parallel deployment of large ev fleets with huge investments in elec generation and grid capacity. My fear is this is going to come too little and too late."

We won't need new generation and grid capacity for night time charging for at least 10 years, and wind can easily grow to the size needed in that time.

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praetzel on September 16, 2007 - 6:57am Permalink | Subthread | Parent | Comments top

VW already has a 1L/100km car - it only carries 2 people in tandom. A Prius will never be a fuel efficient car as it's big and heavy and designed to go fast. It's got a monster engine that is running at such a tiny fraction of full throttle and has to operate over such a wide range of RPMs that it'll never be efficient.
The only real option is a 4hp IC/heat/turbine engine which generates the average power necessary for a car. That also generates a continous source of heat which is necessary for those of us outside la-la land where we have fall - winter and spring and -30C weather.
Parallel hybrids are useless with only marginal gains over a small IC car (and the gains are really only in the city driving - driving which is most easily avoided).
In short a parallel hybrid is a solution to a non-existant problem; it's just for people who wish to appear green and refuse to accept that radical reduction in energy use and change in lifestyle is necessary.

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damac on September 16, 2007 - 9:31pm Permalink | Subthread | Parent | Comments top

VW already has a 1L/100km car - it only carries 2 people in tandom. A Prius will never be a fuel efficient car as it's big and heavy and designed to go fast. It's got a monster engine that is running at such a tiny fraction of full throttle and has to operate over such a wide range of RPMs that it'll never be efficient.

Oh, man, this made me actually laugh out loud. I take it you don't own a Prius, nor have ever driven one.
Big? Well, it's classified as a mid-sized car. So, not big, and not small. Compared to other mid-sized cars, at ~2700 lbs. it weighs anywhere from 500 to 1,000 lbs. less than other cars in its class. Granted, 2700 lbs. does not make it a potato chip, but then I'm less likely to get squashed by a Ford F-350. That 'monster' engine you refer to is a 1.5L four cylinder. That eliminates the 'fast' part right away. With the electric assist, it can get out of it's own way, but I'm not about to race for pinks anytime soon.

It's unfair to compare a 2 person VW test vehicle to a mid-sized production car that can carry four plus their luggage. I'm averaging about 50mpg in my Prius. Efficiency is not a destination, but a sliding scale. The Prius isn't perfect, but it's more than twice as efficient as my last car.

. . and please elaborate how a 4hp engine of any type will move anything heavier than a small motorbike.

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147 comments on A Tale of Two Speeches--OPEC's Demand Side Fear Is Very Real

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