How much electricity to produce gasoline?

[JRP3]

I agree that since we are talking about a future use of NG then it's quite reasonable to assume the more efficient use of it at 60%.
As for using numbers with the general public VFX is correct, but most of the time I'm arguing with more sophisticated people and sloppy numbers will get cut to pieces, as they should.

[Norbert]

I agree that since we are talking about a future use of NG then it's quite reasonable to assume the more efficient use of it at 60%.
As for using numbers with the general public VFX is correct, but most of the time I'm arguing with more sophisticated people and sloppy numbers will get cut to pieces, as they should.

Yes, and in so far as we are talking about an actual future use, nothing would force us to use the same combination of fossil fuels as a refinery. So it appears a valid scenario to say that we would use NG across the board to replace consumption by refineries. (Though actually we will increase solar significantly which is likely to soon achieve grid parity.)

So we could say that if we produce electricity from an equivalent amount of NG, replacing the fossil fuels consumed by refineries, we could produce about (6.7 kWh - 0.31 kWh) * 0.60 + 0.31 kWh, where 0.31 kWh is the number calculated by stopcrazypp, and this would be a bit more than 4.1 kWh.

So we could produce more than 80% of the electricity needed (which would be 5 kWh).

[Still, that wouldn't be the end of the calculation, there is still nighttime electricity, transportation of oil and its protection, and much more, to be factored in.]

[Norbert]

And this also seems the case in terms of the cost of operating EVs with electricity:

The refinery energy loss of about 17% (excluding "less desirable" products) is (currently) roughly about the same as the relative cost of operating an EV vs the cost of gas, which seems to be about 20% (at about $4 per gallon).

[stopcrazypp]

But, if you go that far, why do you stop at that point (at refineries) instead of going further and including electricity that is available in the night (off peak), for example?

Off peak electricity isn't exactly free. We have the power generating capacity to power 80% of the fleet on off-peak electricity, but at that point, the overall efficiency of the plants will end up very similar to baseload and peak hours. The only "free" part of offpeak comes from the difference in efficiency of a plant running under very low loads and a plant to running at baseload or at full capacity. In other words, that advantage will average out to the figures we have now.

I don't see why you would think that using averages including old plants would be more in some "spirit". If 60% efficiency to process that NG is possible, then I don't see a reason not to actually do this. The idea isn't to keep wasting the energy except to use it for EVs. I'm talking about the possible future reality, not about a restricted thought experiment.

It's more in the spirit because that presents a snapshot in time where that scenario can happen (nationwide average refinery efficiency, nationwide average powerplant efficiency to convert feedstocks to electricity). This is purely factual, without any bias toward a certain side. I dislike talking about "possible future reality" using the best figures (60% efficient natural gas plants) for the technology you want to support and average figures (83% efficient refineries) for the technology you are against. Virtually all technology can be easily justified if you use this kind of comparison (which is frequently used in optimistic press releases of the companies trying to push a certain technology).

As far as I can tell from the ANL study right now, coal isn't used, but very much something called "still gas"...

Coal was still listed in the ANL study I linked to, perhaps not in the updated report you posted.

I'm not sure what you refer to as 1 kWh at the end, but I can now see how you would arrive at 2.4 to 3 kWh, even though I would still arrive at a larger number (probably closer to 4% than to 3%, at least if "still gas" could be processed as effectively as NG).

1kWh I got from purely using natural gas, steam, and coal. I didn't factor in LPG and the other types of gases yet. But in the end, I think you'll arrive with around the 2.4 to 3 kWh in my rough estimate if you factoring all those gases.

And once more, it should be pointed out that the long tail pipe argument is most often mentioned in the context of CO2 production, and in that context, the number of around 6.7 kWh for the amount in refineries which corresponds to CO2 production of electricity for EVs, still seems the closest estimate.

I agree with this. I always include the refining efficiency on the ICE side when comparing CO2 emissions. It is akin to including the transmission efficiency for electricity. But talking about using electricity directly from refining is a whole other matter.

[Norbert]

Off peak electricity isn't exactly free. We have the power generating capacity to power 80% of the fleet on off-peak electricity, but at that point, the overall efficiency of the plants will end up very similar to baseload and peak hours. The only "free" part of offpeak comes from the difference in efficiency of a plant running under very low loads and a plant to running at baseload or at full capacity. In other words, that advantage will average out to the figures we have now.

I have heard many times that there is electricity available since they don't want to turn off some of the power plants. That doesn't mean that they give it to you for free. While I haven't seen numbers for that yet, I'd expect that it is factored into the lower cost of off-peak electricity.

It's more in the spirit because that presents a snapshot in time where that scenario can happen (nationwide average refinery efficiency, nationwide average powerplant efficiency to convert feedstocks to electricity). This is purely factual, without any bias toward a certain side. I dislike talking about "possible future reality" using the best figures (60% efficient natural gas plants) for the technology you want to support and average figures (83% efficient refineries) for the technology you are against. Virtually all technology can be easily justified if you use this kind of comparison (which is frequently used in optimistic press releases of the companies trying to push a certain technology).

I disagree with this. You are implying that it might be possible to improve the efficiency of refineries to the same level as it will indeed be possible to improve the effieciency of NG plants. But there is no basis in fact to believe that, whereas there is a basis to believe it for NG plants.

Coal was still listed in the ANL study I linked to, perhaps not in the updated report you posted.

It is listed in Table 4 of your link, but with 0%. Unless I'm missing something else.

1kWh I got from purely using natural gas, steam, and coal. I didn't factor in LPG and the other types of gases yet. But in the end, I think you'll arrive with around the 2.4 to 3 kWh in my rough estimate if you factoring all those gases.

So you think if we were to produce electricity after closing a refinery, we would use the "still gas", "steam", etc., which it has consumed ? I'm sure we would not.

I agree with this. I always include the refining efficiency on the ICE side when comparing CO2 emissions. It is akin to including the transmission efficiency for electricity. But talking about using electricity directly from refining is a whole other matter.

It wouldn't be "directly from refining" if it actually happened (as opposed to thought experiments).

[JRP3]

I have heard many times that there is electricity available since they don't want to turn off some of the power plants. That doesn't mean that they give it to you for free. While I haven't seen numbers for that yet, I'd expect that it is factored into the lower cost of off-peak electricity.

I'm still not clear on the reality of this. Some have said there is only excess capacity at night, not excess electricity, which would mean running power to ground or giant resistors. This may happen on occasion for short periods of frequency regulation or load changes. There is also the likely hood of steam bypass, which keeps the boilers running, and obviously still burning fuel, but dumps steam so as not to produce electricity. Again, I think these are short term events. On the other hand I have heard that power plants contract with some industry to take excess electricity at night, and may even pay them to do so. How widespread is this practice, I don't know.

[stopcrazypp]

I have heard many times that there is electricity available since they don't want to turn off some of the power plants. That doesn't mean that they give it to you for free. While I haven't seen numbers for that yet, I'd expect that it is factored into the lower cost of off-peak electricity.

There's no real excess electricity produced at any point in time (otherwise they need resistor banks like JRP3 says). What they do is run the generators at a lower less efficient level. For instantaneous drops in demand, they do something similar to what JRP3 says, which is allow steam pressure to rise so output is decreased (steam bypass is only a last resort for very extreme drops). Most of the lower cost of off-peak electricity comes from not having to run less efficient peaking plants (basically turbine plants that can be turned on and off very quickly and can be throttled easily compared to baseload plants). But as I said, the kind of savings you get from off-peak will average out as more EVs come on the grid (and the baseload plants no longer have to throttle down).

I disagree with this. You are implying that it might be possible to improve the efficiency of refineries to the same level as it will indeed be possible to improve the effieciency of NG plants. But there is no basis in fact to believe that, whereas there is a basis to believe it for NG plants.

Actual, for one, it IS possible! The best for NG plants is 20% better than the 40% average I used. On the refinery side, it only needs to improve 3.4% (20% of the 17% losses) to have the same impact. I don't see how that is impossible.

And given 83% average refinery efficiency, unless all plants in the US run at 83%, there has to be a refinery in the US that runs higher than 83%. Therefore, it is inherently unfair to compare the best 60% efficient NG plant to average 83% efficient refineries in the US.

And the problem with using "best" in comparisons is that "best" usually changes quickly, and it's hard to verify the figure you have is really the best for the industry. Averages don't change very quickly and with a large enough data set, even if you miss one or two data points, you usually aren't off by a significant amount.

It is listed in Table 4 of your link, but with 0%. Unless I'm missing something else.

This is the case where 0% doesn't equal 0 (a fact many food advertisers take advantage of). Table 2 shows 34 thousand short tons of coal being used.

So you think if we were to produce electricity after closing a refinery, we would use the "still gas", "steam", etc., which it has consumed ? I'm sure we would not.

If you assume we won't use those resources at all, then all that will do is reduce the amount of electricity you can theoretically get to even lower than the 2.4-3kWh figure I got from using 40% efficiency. I think using 40% is already pretty generous, because I'm already making the implicit assumption there that all of the resources used by the refineries are equivalent to natural gas, and also because natural gas plants are the most efficient fossil fuel plants (even looking at averages).

It wouldn't be "directly from refining" if it actually happened (as opposed to thought experiments).

This is just my short way of summarizing the current topic (perhaps phrased badly). At first, the argument was looking only at electricity used in the refinery process. We found purchased electricity to be relatively insignificant and couldn't find figures for internally generated electricity. So the topic shifted to how much electricity can be made from the resources that refineries use to make gasoline (plus the purchased electricity of course).

[VolkerP]

JR,

it depends on the type and characteristics of power plant. Nuclear (fission) plants can decrease output from 100% to 60ish but not much lower. They need several days to recover from shutdown before it is safe to start them up again. Coal fired plants can ramp up/down within hours. Thermal expansion of steam boilers must not be rushed. Natural gas fired plants can fire up very quickly and can operate in a wide range, as well as hydro.

Contracts are traded to provide electricity by the hour of day, and in night time these contracts can have negative prices. Happens several times a year here, e.g. on sunny/windy weekends, when renewable energy output reaches near total demand. My favorite site on that subject: PV electricity produced in Germany.SMA Solar Technology AG

[Norbert]

There's no real excess electricity produced at any point in time (otherwise they need resistor banks like JRP3 says).

Does it have to be "real excess"? A better use of existing plants is still a significant advantage, just more difficult factor into the discussion and calculation. In any case, it is only one of several additional resource savings such as also transport.

Therefore, it is inherently unfair to compare the best 60% efficient NG plant to average 83% efficient refineries in the US.

The point you are missing is that if we close a refinery and build a NG plant instead, then it would be natural (not unfair) to *actually* use the best technology available. Whereas we have no information (at least not so far, on the table) that refineries are *actually* improving their efficiency. I suppose they already would have, if they could have, but even then it would probably only happen when building new refineries which AFAIK is not happening since gas consumption is decreasing. So even if there were improvements in refining technology they would not likely get used any time soon.

This is the case where 0% doesn't equal 0 (a fact many food advertisers take advantage of). Table 2 shows 34 thousand short tons of coal being used.

I'm not sure what you are saying. That it is 0.4% and not 0% ?

If you assume we won't use those resources at all, then all that will do is reduce the amount of electricity you can theoretically get to even lower than the 2.4-3kWh figure I got from using 40% efficiency. I think using 40% is already pretty generous, because I'm already making the implicit assumption there that all of the resources used by the refineries are equivalent to natural gas, and also because natural gas plants are the most efficient fossil fuel plants (even looking at averages).

See below.

This is just my short way of summarizing the current topic (perhaps phrased badly). At first, the argument was looking only at electricity used in the refinery process. We found purchased electricity to be relatively insignificant and couldn't find figures for internally generated electricity. So the topic shifted to how much electricity can be made from the resources that refineries use to make gasoline (plus the purchased electricity of course).

No, as I have already said repeatedly, I'm meanwhile talking about what we would actually do, if we actually did close a refinery or two (as anything else would be a restricted thought experiment of only academic value). We would surely not use the exact same resources, since we would (or actually will) be free to use any resource we choose. That might be solar, at least in the future when it reaches grid parity, or currently NG with that 60% technology assuming that it is *in fact* already available.

As far as your original point in its original context is concerned, I have already said in 2009 (in this thread) that the term "energy" should be used instead of "electricity".

So based on the information now on the table, the point remains valid that we could produce about 4.1 kWh, which is about 80% of the needed electricity, from an equivalent amount of fossil fuels as is spent (wasted) in refining gasoline.

(EDIT: with that, I'd like to come to a temporary end of this discussion)

[dpeilow]

Page 78, section 11.2: http://www.ifeu.de/verkehrundumwelt/...n_China_GB.pdf

And the reference (in German) http://www.ifeu.de/verkehrundumwelt/...7%20100326.pdf