How much electricity to produce gasoline?

[graham]

I have seen many arguments that electric cars will overload the grid. Typically the argument is that we already have rolling brownouts and blackouts and having cars plugged in will only make it worse.

Additionally today while electric cars are so relatively expensive, I bet a large percentage of owners are considering generating their own power by solar. Of course as the price of electric cars falls, and the price of solar does not, that equation does change.

 

[JRP3]

People keep talking about these rolling brownouts as a regular occurrence.
I can't remember one happening in my area in years. Not to mention if you ever do lose power you've got a large backup power supply sitting in your driveway.

 

[Palpatine]

Get some solar panels if you are worried about rolling brownouts.
Then get a battery backup storage cells with about 10 kwh of energy storage to get you through the evening when your solar panels are not producing.

A 10 kwh battery (lifepo4 with 3,000 cycles) system will cost you about $3,000 to $4,000.
You could likely get by on a 5 kwh battery system.

 

[johnr]

Of course as the price of electric cars falls, and the price of solar does not, that equation does change.

I'd have to respectfully disagree with you there. The price of solar has also been steadily falling over the years. It did go up for a while due to the silicon shortage, but other than that it's been steadily falling. Recently I'm seeing the price dropping even more rapidly than usual, and I expect the trend to continue for the forseeable future.
http://www.solarbuzz.com/Moduleprices.htm

 

[Serge]

The price of solar has also been steadily falling over the years.

And they keep falling

 

[doug]

Tangents on the cost of solar panels and CFLs aside (stay on topic people ), do we have a definitive answer and reference on this yet?

That is, how much electricity is used to refine 1 gallon of gasoline?

It's a complicated question because of course refineries produce more products out of crude oil than just gasoline for automotive purposes. It's unclear how to properly account for the energy required for gasoline alone. Also some refineries use waste heat from the process to drive steam turbine cogeneration which offsets some of the power usage.

This resource has some info on electricity usage, but not in a readily useful form:
Electricity Shortage in California: Issues for Petroleum and Natural Gas Supply

 

[doug]

It takes 7.5 kWh of electricity to refine 1 US gal of gas. 7.... on Twitpic

 

[Brent]

It takes 7.5 kWh of electricity to refine 1 US gal of gas. 7.... on Twitpic

Good find!

 

[Norbert]

It takes 7.5 kWh of electricity to refine 1 US gal of gas. 7.... on Twitpic

However, that seems to be just for "refining", and doesn't include producing the oil.

According to the post at FuturePundit: Pickens Versus FedEx On Natural Gas Versus Electric Cars by "Randy Jackson said at April 3, 2009 8:39 PM", which references a list of sources, the energy required for producing gas is larger than that for refining, so even though he estimates refining at only 4 kWh, her arrives at a total of 12kWh.

It seems surprisingly difficult to find an authoritative source for these numbers...

 

[Brent]

It seems surprisingly difficult to find an authoritative source for these numbers...

I asked this question on Joe Romm's Climate Progress blog. The only reply I got indicated that refineries are net producers of electricity, as they use waste gas to generate it. On the other hand, I also read somewhere that oil refineries are among California's largest consumers of electricity, just behind the water companies that pump water over the hill into L.A. So, net net...no clue.

 

[Serge]

However, that seems to be just for "refining", and doesn't include producing the oil.
It seems surprisingly difficult to find an authoritative source for these numbers...

My guess would be that electricity makes up a relatively small portion of upstream (exploration and production) energy costs.

On the other hand, implications of 7.5 kWh/gallon refinery consumption are quite significant. As noted, an EV can travel 30 miles on this amount of electricity. A small efficient gasser travels the same distance on 1 gallon of gasoline. Mile-for-mile "the Grid" has to produce equivalent amount of electricity in either scenario. With gasoline add economic and environmental costs associated with production, distribution and burning of hydrocarbons in an ICE.

I asked this question on Joe Romm's Climate Progress blog. The only reply I got indicated that refineries are net producers of electricity, as they use waste gas to generate it. On the other hand, I also read somewhere that oil refineries are among California's largest consumers of electricity, just behind the water companies that pump water over the hill into L.A. So, net net...no clue.

Logic dictates that refinery is "net producer" only in case a well, the source of crude and "waste gas," is located relatively close by. Perhaps LA-based refineries process crude shipped from elsewhere and local supply of "waste gas" is non-existent or insufficient (rigs off the coast?). If that is true (and Nissan's calculations check out), SoCal's grid is prepared for the massive replacement of gassers with xEVs :biggrin:

 

[vfx]

The largest user of Electricity in Los Angeles is Los Angeles.

The 2nd largest user of Electricity in Los Angeles is the Massive Oil Refinery in the South Bay

 

[vfx]

By the way, This is really huge. A major Automaker brings to the front an argument that EV advocates have only been able to dance around. Even better they have given it a number. 7.5 is good for 30 miles of Tesla driving before the gas is even made.

We now have a credible source for the long tailpipe argument .


This still needs some work:

Ignorant Consumer:
"Electric cars just moves the pollution to somewhere else".
EV expert:
"The production of gasoline does the same thing'

OR

"I can drive 30 miles on the electricity it takes to MAKE a gallon of gas".

OR

"So you are saying gasoline makes pollution right?
And you are saying that generating some electricity makes pollution?
Did you also know that it takes massive amounts of electricity to make gasoline?

OR

"Then gasoline is a double polluter. It takes electricity to make gas."

 

[Tdave]

It takes 7.5 kWh of electricity to refine 1 US gal of gas. 7.... on Twitpic

Wow, looks like that took that statement almost verbatim from this exact thread. The coincidence is too great for them not to have gotten the idea from us.

 

[doug]

We now have a credible source for the long tailpipe argument .

I'd prefer something a little more concrete than a photo of a poster. Maybe the Leaf folks can point us to a source.

 

[vfx]

I'd prefer something a little more concrete than a photo of a poster....

Or ink on paper or download from a blog. It's from Nissan. They used to be Datsun for crying out loud.

Sources are listed in this thread.

Gasoline is Double Dirty.

 

[Alfred]

Refineries and electricity use

Electricity used in refining cannot be readily estimated because:

Refinery designs are optimised for a certain crude diet and product mix. "Refinery fuel and loss" will vary and could be typically around 5% of the tonnage of crude used. How much electricity a refinery decides to import as portion of fuel and loss depends on local tariffs granted to large industries and the reliability of this supply. If tariffs are low, they will take more. If they are high they may import none. It is largely a matter of local economics and safety whether e.g. pumps are driven by steam or electricity.
Refining is a fractured distillation with various additional units. In the US, where demand for gasoline is relatively large in relation to other products, e.g. catalytic crackers have to be added to produce more of the lighter fractions. As refinery fuel serve always the cheapest fractions, if possible those that cannot be sold anyway. The largest portion would be heavy residues. Of those 5% only a portion would be used for electricity generation, unless the refinery can export such electricity profitably.

If I assume that primarily demand for gasoline will be reduced with the introduction of electric vehicles, I would allocate only the additional energy used to operate crackers and perhaps some other gasoline specific units as a possible benefit.
To estimate the effect of omitting such units the (linear program) model of a specific refinery would have to be used. In any case the "saving" would not emerge as electricity, but rather as a reduction in refinery fuel and loss.

 

[Tdave]

I think Nissan, as well as all of us, should be careful not to say, "It takes 7.5kWh of electricity to refine a gallon of gasoline", and instead say, "It takes 7.5kWh of energy to refine a gallon of gasoline". Then go on to say that our cars can go 25-30 miles on that same amount of energy.

Alfred's info makes it clear as to why.

Our point remains valid, as refineries still get their energy from fossil fuels primarily, and electricity from the grid secondarily.

 

[Norbert]

How much electricity a refinery decides to import as portion of fuel and loss depends on local tariffs granted to large industries and the reliability of this supply. If tariffs are low, they will take more. If they are high they may import none. It is largely a matter of local economics and safety whether e.g. pumps are driven by steam or electricity.

I think the interesting number would be: What is the amount of electricity a refinery would use if the tariffs were very low. It still seems that this number should be obtainable.

It also seems that this number might be a prerequisite, and should be much easier to obtain than the ones needed for the more complex calculations which your message suggests, such as what happens if the consumption of gasoline is reduced while the refinery still processes the same amount of crude oil for other reasons.

 

[vfx]

One word:

averages