How much electricity does an oil refinery use?

I hope your point isn't that since we can't nail down the real number... that we should just make it up with financials? Or did you have another point that I missed? I have numbers on the page I linked to earlier that are WAY more "actual" and "reliable" than taking a WAG with the financials.

 

Yes thank you this is exactly my point.

 

DarrellDD- Sorry if my lasy post was a little unfair. I am trying to develop energy/environment positions and you are keeping me on my toes. As I see your (or generic pro-EV) challenge, you are trying to infer lots of excess energy needed for conventional fuels. Then the burden is on the other side to list exactly all the energy inputs to confirm or refute this assertion. But its a complex PhD thesis calc, so I was going for more logical agrument with some math. And I stooped to a few other tactics.

 

Here is another complication for you. If you are charging your EV at night, using electricity which would otherwise have no use, what is the impact of that on your energy/environmental position?



Sorry.

 

And another. What if you plug your EV in when you get home from work, and the grid uses part of the remaining charge to offset some peak power requirements. (and later charges it back up of course)?

What if you are getting paid going rates for that power? (i.e. getting paid at peak rates, and buying at slack rates)?

 

There is no "wasted" electricity at night (well, unless you count the recent issue in the NorthWest where there is so much hydro thanks to the huge amounts of rain/snow they get this winter that they've had to shut down wind to avoid over powering the grid).

Now - charging during off-peak hours could improve efficiency of the grid by allowing generation sources to run more of a constant load.

Right now I don't think there's any way to do that legally. But you can get halfway there with home solar where the utility will let you offset your bill using TOU rates.

Around here, the peak TOU rate in the summer (May-Oct) is about double the off-peak rate - ~15c / kWh vs ~30c / kWh. So assuming you could fully utilize this with about 20 kWh of storage, you could make about $3/day assuming negligible charge/discharge losses.

I think it'd be more valuable to use that battery for grid regulation rather than peak load offsets. That lets generators run closer to constant load and avoids full charge/discharge cycles of the battery which is much harder on the battery than a lot of small charge/discharges.

 

I am not an electrical engineer, but on the surface, charging up at nite sounds has possible merit. My understanding however is electricity cannot be stored (I know this is an approximation because, for example, Smith Mountain Lake reservoir here in Virginia can reverse pump water upstream at nite). If electric power cannot be stored, then charging EV at nite simply means we have to run the power plants harder at nite to meet the demand. There is no capability to make wasted power at nite, because there is no place to put it. So charging at nite may accomplish peak shaving (keeping constant current flow). This is a CO2 neutral accomplishment, but allows us to get better use from existing steel on the ground (less power plants needed). If it further accomplishes less inefficient coal burning, then I am definitely on-board. I further strongly feel that solving the energy problem requires a variety of approaches, so I would be inclusive of EV+PHEV+wind+solar+renewable+all fossil fuels in my proposed solution. I am pro-practical solution and I will not be against any efficient, cost-effective approach or solution. I also do not oppose some subsidy for new ideas. I like R&D. Directionally CO2 causes global warming but not sure if that "trumps" the need to conserve/supply energy to mankind for future.

 

It depends on your definition of "wasted" really. We have plants that can't be idled. And we have plants that are WAY more efficient if they are NOT idled, and are instead producing some power. In general, using power at off-peak times makes the grid quite a bit more efficient. And while it may mean more kWh's used, it also means that each kWh consumed is cleaner per unit of energy, and cheaper to produce. Adding EVs to the mix is not as simple as "we need more dirty power."

 

I'll stop you right there, and ask you what batteries can do - the "tank" of an EV if you will. Batteries store electricity.

While home AC units are all running during peak times (this of course is what causes the peak!), EVs can charge at night when power is the cleanest and most efficient to product. The energy can then be stored until daytime when the car is then driving around NOT using the dirty peak energy being produced by the power plants.

 

Darell, why do you say that energy is cleaner from the grid at night ? The studies I have read say that in general night time is coal, while peak is NG.

 

Depending on your definitions, batteries don't really store electricity. They store chemical energy; just like pump stations moving water to higher elevation store potential energy. Capacitors do store electrical energy (charge).

All these load balancing methods have their efficiency losses, but are better than an idle plant which still consumes fuel, or a renewable plant shut down.

 

There is plenty of capacity to make power at night. That is the problem with being unable to store electricity. Charging at night means that plants which can not be shutdown at night (Nuclear being the big one) are performing a useful role. Eventually, we might need enough to keep plants that would otherwise be shut down up, but until then it is strictly a win.

 

According to Argonne National Laboratory's GREET model (currently the industry standard - EPA uses it in its CO2 calculations on the fueleconomy.gov site), the national average of energy used in the production of the "fuel" per gallon of gasoline equivalent (gge) is 23,256 BTU for gasoline and 166,871 BTU for electricity. ANL defines a gge as 113,602 BTU. The overall well-to-wheels (WTW) energy consumption per gge is 136,858 BTU for gasoline and 280,473 BTU for electricity.

Since the Leaf (for example) gets about twice the "fuel mileage" as the Prius (99 mpg for the Leaf and 50 mpg for the Prius per fuelconomy.gov), the overall energy used is roughly equivalent per unit distance traveled.

The "mini-tool" for calculating these values is available at Argonne GREET Sample Results .

 

Let me try to put a number on "roughly equivalent" using your numbers:

(280473/136858)*(50/99) = 3.5% more CO2 emissions per mile in a LEAF compared to a Prius. Correct ?

We should also realize that the EV will do relatively worse in the winter compared to a Prius, because cabin heating does not have ICE waste heat to take advantage of.

 

Actually, that same GREET "min-tool" has CO2e emissions per gge also - 10,994 gCO2e/gge for gasoline and 23,780 gCO2e/gge for electricity.

23,780/10,994 X 50/99 = 1.092 = 9.2% more CO2e per unit distance traveled for the Leaf, according to GREET.

 

The batteries in the EVs can store the power at night. Night generation is less efficient because plants are kept on simply because start up is more costly. So increasing night demand does an efficiency gain, and on coal powered plants reduces maintenance. In the longer term, it means a more efficient use of assets, so that there is more money to build more efficient plants. Since utilities are regulated, the efficiency gains are tied to public policy.

In the short term it may be co2 neutral. In the longer term with good regulation it reduces polution and helps transition away from the most scarce and expensive resource oil, to more plentiful cheaper resources natural gas and wind. Longer term co2 reduction of the transportation fleet can not be accomplished by simply making gasoline more efficient, which is why the UK is putting forth this public policy.

In the US city wide pollution and scarce politically and economically sensitive oil use are the main drivers to electrify. IMHO those arguing only about short term CO2 and dirty coal either don't understand, are scared of electrics, or have a more evil purpose in this dishonest shift of discussion. I would even define the prius as part of this electrification, and in the future adding a bigger battery and a plug is an obvious way for it to evolve.

Let me stop you there. Please don't over play the hand. Night charging is the cheapest electricity to produce. In some places it actually costs money to not produce the electricity. But others do use older inefficient natural gas in the peak which is "cleaner" than additional coal at night. EV usage does allow for us to pay for a cleaner grid instead of shipping more and more money off each year to a foreign land. EVs and PHEVs make the problem much more solvable but good public policy is needed on the various grids and EPA.

 

We have come far afield from how much power in a refinery, to btus. I suppose this is because you believe all btus are created equal and maybe you want to tax them. If you look earlier in the thread you will see calculations on input to refinery to wheels from.

0.8 kwh oil/mile prius
0.68 kwh natural gas/mile leaf
0 fossil fuel kwh wind/mile leaf

Let me further add that a leaf is much more efficient than the fleet, but there is no savings on a prius because it uses the same amount of gas as a prius, which is my yardstick for a prius. Wait that is the common anti ev argument, they must be compared to a prius which is a crazy notion.

Now when we start doing complex calculations we can lose track of what is really going on. Let's look at the comon criticism of the argone study. First it assumes that EVs will be fueled by the nation wide average, which is clearly false. EVs tend to be bought in more efficient areas of the grid. The next is that we are going to build 70 year old coal plants to fuel these new evs. The new plants are much more than 90% natural gas and wind. Finally is the assumption that oil is equivalent to natural gas and wind, which is the biggest problem. It is not. There is a great deal more natural gas and wind than oil. Lets say infinitely more wind and because natural gas can be made in renewable fashion, although more expensively lots more natural gas. Since there are GTL plants making gasoline out of natural gas, I would only handicap oil by 3 to 2 versus natural gas, but do your own handicapping and grid mix to be built for the new fleet of cars.

If the leaf is fueled by natural gas it only gets a little better mileage per unit energy per above. If it is powered by wind it won't use any at all.

Now if the leaf were displacing only prii, and the only important thing was CO2, and all the leaves used the average grid which is not getting cleaner, I would agree with you. But none of these assumptions are remotely correct.

 

@ austingreen - just providing another resource to this discussion. I'm not trying to vouch for its validity, although many studies which I've seen use GREET as a basis for emissions, etc. CARB used GREET to calculate its Low-Carbon Fuel Standard regulations.

By the way, there are many different fuel pathways that can be used in GREET, the average U.S. mix seemed most applicable to me.

 

I don't mean for my post to be harsh on you. It came out a little wrong. I am a little harsh on using the GREET model for the reasons I mentioned above.

From a policy point of view we must be forward not backward looking. If you want to make the fleet less polluting and use less oil you can only go so far keeping everything running on gasoline. The grid is getting greener and more efficient. The median vehicle is over 9 years old, and the average is less than 18mpg. If we continue in this way, the problem is not solvable. PHEVs and EVs are a possible solution. The grid is already adding the power mix to make these both more efficient and less polluting than comparable cars. The trick is to get the price down, the sales up, and the grid to accelerate its greening. The prius is pretty much tapped out as per market share. Soon we will have a generation of Rav4 ev, C-Max-energi, Tesla S, etc that may greatly increase market share. Its really the next generation of these cars and trucks that can seriously impact energy use. Look out to 2020 for the sales, and 2030 for the power source and a much more fair look at PHEV and BEV technology, energy, and polution can be made.

 

Power plants could advance and use technology from Hybrid Synergy Drive, don't you think?

The same was said about the non-hybrid until HSD came along. A simple start-stop technology could do wonders.