Electric cars: What do you think?

[neanderthalphysics]

TL;DR Summary

Are they really worth it?

I have been thinking about electric cars from an engineering point of view. I came to the conclusion that they are not worth it, for a number of reasons I will list below. What do you guys think?

1) Energy to charge the batteries must come from somewhere.
If the source of the energy is nuclear, fair enough, the energy source has no carbon footprint. But if the source of energy is from an gas/oil power plant, you are exchanging one fossil fuel engine for another one. The power plant is probably more efficient especially if it is a combined heat & power plant, but still.

2) Batteries age
Gas or diesel can sit happy in storage tanks for hundreds of years. Batteries age; any charge held in them is lost over time and furthermore, over time they lose their maximum charge level.

3) Safety of batteries
Batteries are basically sealed units with both the oxidizing + reducing agents mixed together in intimate contact. Which means the potential for a runaway reaction is there, waiting for a trigger. Gas or diesel tanks just contain fuel. Almost empty gas tanks contain fuel + oxidizer.

In any event, in an accident, the oxidizer for a gas/diesel powered car must come from the environment. For an electric vehicle, it is all there, pre- and well mixed. It will be very difficult to make the battery compartment of an electric vehicle immune to all sorts of damage which you might get in a conceivable lifetime - crushing damage, piercing, fires, etc.

4) Lifetime carbon footprint of producing batteries
Has anyone looked at whether the lifetime carbon footprint of mining lithium and producing the batteries is worth it?

IMHO the future fuel for cars is hydrogen.

 

[256bits]

How does hydrogen compare in your 4 points?

 

[neanderthalphysics]

1) To produce and store hydrogen also involves an energy investment.
2) Ageing of hydrogen storage - depends on how you store it. If in tanks, you will probably have a small % of leakage year on year, because hydrogen is such a small molecule. If stored as hydrides, the ageing will depend on the chemistry. Other storage methods will probably have their own losses as well.
3) Safety of hydrogen storage. Compressed H2 is explosive because of the pressurisation which would lead to rapid mixing with atmospheric oxygen upon container breach. Hydrides - depends again on chemistry.
4) Lifetime carbon footprint - if nuclear to electrolysis of water, then it is neutral.

 

[russ_watters]

Summary: Are they really worth it?

I don't think their time is here yet, but it is coming in the next few decades. The basic issues I see are similar to what you said:
1. Electric cars are too expensive when measured fairly.
2. Not enough/too slow chargers/range issues.
3. Gas is too cheap.
4. Our power grid burns too much fossil fuel (though this does not affect consumer choices much).

As evidenced by the fact that hybrid car sales dropped significantly over the past few years, I don't think consumers will switch on their own, without a significant change in the landscape.

4) Lifetime carbon footprint of producing batteries
Has anyone looked at whether the lifetime carbon footprint of mining lithium and producing the batteries is worth it?

I'm not sure, but usually the question can be answered in large part by following the money: mining is fossil fuel intensive, so a significant fraction of the cost of mined minerals spent on fuel. A typical car will burn around 5,000 gal of gas over 10 years. A Tesla battery pack is around $5,000, so if half that cost is the energy needed to produce it (it's probably less), that would be about 1,700 gal at today's fuel prices.

 

[Rive]

Link about assumed lifetime CO₂ emission for different car types by country (EU only, see fig. 2 on page 6)

I would say it does not really cut it right now.
Based on Germany, I would say on wind alone it will never be able to cut it.
But I think it worth to keep around, since there are some country already where it is not just for show.

 

[BWV]

Electric cars are a more efficient way to deliver energy to the wheels than internal combustion engines where most of the energy is lost through heat, this is the differentiator that more than makes up for issues with power generation and battery manufacturing.

Union of Concerned Scientists (Nealer, Reichmuth, and Anair, 2015) presented a comprehensive “well-to-wheels” analysis of the greenhouse-gas emissions from driving BEVs compared with those from gasoline-powered vehicles:

Energy source Fuel-economy equivalent (MPGghg)
Coal 29
Oil 29
Natural gas 58
Geothermal 310
Solar 350
Nuclear 2,300
Wind 2,500
Hydro 5,100

so an EV charging from 100% coal generated power has the same CO2 footprint as a 29MPG gasoline-powered car.

Rounding this https://www.eia.gov/tools/faqs/faq.php?id=427&t=3
gives an approximate average US electricity generation mix of 30% coal (plus oil), 35% natgas, 20% nuke, 6.5% wind, 7% hydro, 1.5% solar, so (after fixing an error) an EV on average is equivalent to a gasoline car that gets roughly 60 MPG. http://www.umich.edu/~umtriswt/PDF/SWT-2017-18.pdf
No one that I am aware of takes Hydrogen seriously as a solution for transportation anymore

 

[BWV]

All of the major automakers have now abandoned their H fuel cell programs and embraced EVs, the reason is simple - Hydrogen is a dumb idea:

The entire process of electrolysis, transportation, pumping and fuel-cell conversion would leave only about 20 to 25 percent of the original zerocarbon electricity to drive the motor. In a plug-in hybrid, the process of electricity transmission, charging an onboard battery and discharging that battery would leave 75 to 80 percent of the original electricity to drive the motor. Thus, a plug-in should be able to travel three to four times farther on a kilowatt-hour of renewable electricity than a hydrogen fuelcell vehicle could.

a pure EV is similar to a plug-in hybrid, it just lacks the internal gas generator

http://www.calcars.org/sci-am-romm-frank-apr06.pdf

 

[russ_watters]

A couple of bits of caution there:
1. The second study doesn't include the battery manufacture, which is what the OP asked about.

2. Focusing on the energy mix may be misleading in that it doesn't necessarily accurately reflect the marginal impact on the grid of adding a bunch of cars. E.G, nuclear and hydro are fixed (at best) in the West. If you add a bunch of EV's, the power required to be added to the grid to supply them will come primarily from natural gas, and to a lesser extent wind and solar. I think in the US over the past few years it has been 2/3 or 3/4 natural gas. Though the upside for the US is a lot of that new capacity was replacing coal. Over the next few years though, a lot will replace nuclear, which takes us in the wrong direction.

 

[BWV]

A couple of bits of caution there:
1. The second study doesn't include the battery manufacture, which is what the OP asked about.

2. Focusing on the energy mix may be misleading in that it doesn't necessarily accurately reflect the marginal impact on the grid of adding a bunch of cars. E.G, nuclear and hydro are fixed (at best) in the West. If you add a bunch of EV's, the power required to be added to the grid to supply them will come primarily from natural gas, and to a lesser extent wind and solar. I think in the US over the past few years it has been 2/3 or 3/4 natural gas. Though the upside for the US is a lot of that new capacity was replacing coal. Over the next few years though, a lot will replace nuclear, which takes us in the wrong direction.

Sure, the Union of Concerned Scientist numbers do include battery manufacture but the SciAM does not, but hard to believe it makes a dent in the 50 percentage point efficency differential

But as no new coal plants will be built and renewables are 40-50% of new capacity, it won't change the conclusion that EVs are more efficient and CO2-friendly than gasoline

 

[russ_watters]

Sure, the Union of Concerned Scientist numbers do include battery manufacture but the SciAM does not...

Actually I was referring to the study linked by Rive. You didn't link the UCS study so I didn't read it.

...but hard to believe it makes a dent in the 50 percentage point efficency differential

In the study linked by Rive it accounts for about 10-30% of the lifetime emissions depending on the power mix.

...renewables are 40-50% of new capacity, it won't change the conclusion that EVs are more efficient and CO2-friendly than gasoline

Yes, I just want to make sure we answer the question asked and present an accurate picture.

 

[russ_watters]

Energy source Fuel-economy equivalent (MPGghg)
Coal 29
Oil 29
Natural gas 58
Geothermal 310
Solar 350
Nuclear 2,300
Wind 2,500
Hydro 5,100

so an EV charging from 100% coal generated power has the same CO2 footprint as a 29MPG gasoline-powered car.

Rounding this https://www.eia.gov/tools/faqs/faq.php?id=427&t=3
gives an approximate average US electricity generation mix of 30% coal (plus oil), 35% natgas, 20% nuke, 6.5% wind, 7% hydro, 1.5% solar, so an EV on average is equivalent to a gasoline car that gets roughly 1000 MPG

This math is wrong. It implies that a zero carbon source mixed in any proportion with any carbon producing source yields infinite fuel economy - it's because mpg is an upside-down unit you have to add like a fraction. You have to flip over the mpg to get a pound per mile(or whatever the actual unit is), then add them together, then flip it back over again. The answer is roughly 60 mpgghg, which puts it in line with the other sources.

 

[BWV]

This math is wrong. It implies that a zero carbon source mixed in any proportion with any carbon producing source yields infinite fuel economy - it's because mpg is an upside-down unit you have to add like a fraction. You have to flip over the mpg to get a pound per mile(or whatever the actual unit is), then add them together, then flip it back over again. The answer is roughly 60 mpgghg, which puts it in line with the other sources.

OK, good catch.

 

[Rive]

In the study linked by Rive it accounts for about 10-30% of the lifetime emissions depending on the power mix.

The energy mix part makes the whole picture quite a voodoo, actually. The very same car (or battery) manufactured/used on the Germany side of a border or on the France side, and the difference would make it green or not: like I would buy that...
It is good just enough to back up a 'not yet, but maybe it'll make it with time' opinion.
At least, by my humble opinion

 

[neanderthalphysics]

Gas or diesel cars do not spontaneously catch fire like this.


Batteries already have the oxidizing and reducing agents pre-mixed and in intimate contact (by design). If cellphone batteries and cars can spontaneously catch fire without any apparent direct insult, imagine EV in accidents where the battery packs sustain direct damage. Even worse is if passengers get knocked unconscious due to the accident and then the car catches fire.

 

[anorlunda]

Fires are an important point. If the next generation of batteries actually does deliver 2x or 4x the energy density of lithium batteries, the energy releases after malfunction or accident may be even more drastic.

Of course, gasoline and diesel fuels can explode when gasified, but we have more than 100 years experience handling them, and handling fuel fires.

 

[OmCheeto]

Gas or diesel cars do not spontaneously catch fire like this.


...

Um... Yes they do. All the cars in this video are gasoline powered. They recalled affected vehicles with defective PCV systems. I am not aware of any all electric vehicles with "crankcases".

 

[BWV]

EVs currently are luxury goods, allowing consumers to signal both virtue and socio-economic status.

Not sure why plug-in hybrids are not more popular - I have been driving a Honda Clarity for about a year now and can't imagine either going back to gasoline-only or giving up the flexibility of being able to fill my 7 gallon tank if needed. I can do my daily commute on 100% battery, with 17kwh (about $1.35 of electricity charging at home) giving a 45 mile range (about equal to a gallon of gas). The electric drive train is a superior technology, with less moving parts and a smoother, quieter ride.

 

[neanderthalphysics]

Um... Yes they do. All the cars in this video are gasoline powered. They recalled affected vehicles with defective PCV systems. I am not aware of any all electric vehicles with "crankcases".

Gasoline powered only or hybrids that caught fire?

Some of the cars in the news clip are specifically described as cars not affected by the recall.

In any case if we talk chemistry here, if a gasoline/diesel only car spontaneously catches fire, there is a defective part and probably an unfortunate set of circumstances such as a near-empty tank. Gasoline or diesel by themselves don't burn without oxygen. A lithium battery will "burn" (or undergo thermal runaway) by itself without oxygen.

 

[BWV]

Gasoline powered only or hybrids that caught fire?

Some of the cars in the news clip are specifically described as cars not affected by the recall.

In any case if we talk chemistry here, if a gasoline/diesel only car spontaneously catches fire, there is a defective part and probably an unfortunate set of circumstances such as a near-empty tank. Gasoline or diesel by themselves don't burn without oxygen. A lithium battery will "burn" (or undergo thermal runaway) by itself without oxygen.

Looks to be gas-only cars in this story

s.go.com/US/bmw-recalls-million-vehicles-fire-risk/story?id=50922136

 

[OmCheeto]

Gasoline powered only or hybrids that caught fire?

Some of the cars in the news clip are specifically described as cars not affected by the recall.

The video is 2½ years old. My brief googling found that they've expanded the recall even this year.

 

[JBA]

The above ignores two items relative to metropolitan (which is about 80% of our USA population) BEV usage.
First; there is the reduction of concentrated ICE pollution from commuters within those areas. The conversion from ICE to electric is a 100% reduction for every ICE vehicle replaced by a BEV. At the same time, the total energy consumption is also reduced by the higher efficiency BEV's, no more thousands of vehicles consuming energy while idling at intersections or parked on over crowded freeways.
Second, alternative energy sources are growing without the equal necessity for corresponding increased crude based pollution. For every additional amount of fuel required there is an additional amount of pollution and energy consumption associated with drilling and completing the required producing wells, crude transportation, refining of crude into usable fuels and and distribution of those fuels; none of which are required for alternative energy sources (I have intentionally not included the effects of distribution facility expansion because that is required in either case).

As to available BEV charging facilities, there are, at latest count, over 20,000 charging stations supplying 68,800 charging points across the US.

Additionally, I think the grid load issue maybe a bit overstated, (at least for the present) because the majority of BEV users have home chargers that are used during the low overnight peak power consumption period and with the current expansion of BEV mileages do not require any added daytime or evening additional charging.

Most importantly, converting to BEV's is also about dealing with the ever increasing amount of transportation and energy that is going to be required as our global population continues to expand exponentially. More energy demand is going to inevitably be required and the last thing this world needs is for crude to be the required or selected source.

As for any bias on my part, I spent my 40 year engineering career in the petroleum energy industry including involvement in its every stage, from E&C of international production and tanker loading facilities to crude well drilling and production to refining, so I am well aware of the issues associated with crude based energy.

 

[russ_watters]

The energy mix part makes the whole picture quite a voodoo, actually. The very same car (or battery) manufactured/used on the Germany side of a border or on the France side, and the difference would make it green or not: like I would buy that...
It is good just enough to back up a 'not yet, but maybe it'll make it with time' opinion.
At least, by my humble opinion

EVs currently are luxury goods, allowing consumers to signal both virtue and socio-economic status.

I was literally writing this before seeing those:

I read an op-ed recently, where the opinion was presented that focusing so heavily on individual carbon reduction is a bad thing (even calling it essentially a form of denialism, which is a bit much...). We carbon-shame the royals and rich people and virtue-signal with the buying of EVs, but these things are largely inconsequential or cart-before-the-horse.

So far essentially none of the carbon reduction effort has been shouldered by industry/government (with the minor exception of California), which is where almost all of it is needed. Even things like subsidizing EVs and residential rooftop solar are missing the mark. Without a clean grid, electric cars don't help much, so while it feels nice to encourage them, applying direct money to direct carbon reduction gives a much bigger bang for the buck, and avoids the problems on the backside that are currently ignored because they are inconsequential.

So I share your opinion and while I think it is nice to buy an electric car, I probably give the impression of downplaying it because compared to industrial carbon reduction because I do indeed think it is far less important and counterproductive if it serves as a delay/distraction. Yes, it's voodoo, and the question of whether I'd save 10% or 60% in carbon footprint by buying an electric car is just too complicated and indicative that it's not a great solution. By contrast if we replace a 1 GW, 90% capacity factor coal plant with a 1GW, 90% capacity factor nuclear plant, it is crystal clear how much we save.

 

[russ_watters]

The above ignores two items relative to metropolitan (which is about 80% of our USA population) BEV usage.
First; there is the reduction of concentrated ICE pollution from commuters within those areas. The conversion from ICE to electric is a 100% reduction for every ICE vehicle replaced by a BEV.

I cringed a little at reading that, and I hope you didn't mean it to sound like you want to export pollution from cities to rural areas...which is of course how it already works.

I'm not sure I see a clear goal here except to make life better for people in cities by reducing in-city pollution. Isn't the larger goal to combat climate change?

At the same time, the total energy consumption is also reduced by the higher efficiency BEV's, no more thousands of vehicles consuming energy while idling at intersections or parked on over crowded freeways.

Yes, that's a viable goal, but almost all of it can be achieved with a hybrid car. EVs may be a nice to have there, but their benefit vs a hybrid is pretty insignificant.

Additionally, I think the grid load issue maybe a bit overstated, (at least for the present) because the majority of BEV users have home chargers that are used during the low overnight peak power consumption period and with the current expansion of BEV mileages do not require any added daytime or evening additional charging.

Well, sure, the downsides of an insignificant thing tend to be insignificant. But isn't the goal here to make the impact of EVs significant? If that's the case, then you have to take the significant downside along with the significant upside -- you can't have one without the other. Converting a significant fraction of cars to EVs without increasing pollution will require a significant increase in the number of power plants capable of providing clean energy, with flexibility to provide a significant amount of it day or night, in good weather or bad.

Many municipalities in California are aiming to go a step further by banning natural gas for new construction, with the eventual goal of phasing it out (it will take maybe 30 years). If that happens, then the grid will peak at night, during the winter, maximizing the collective downsides of EVs and intermittent renewable energy. That's a big, big problem that they are planning to cause, with no plan to solve it. Then we'll be arguing if 3.0 COP heat pumps powered by natural 45% efficient natural gas power plants are better or worse than 95% efficient natural gas furnaces and nothing will have actually changed emissions-wise.

That's why it is so important to address the grid first.

 

[neanderthalphysics]

Here's why I have problems believing any car that spontaneously starts burning when off are not 100% gas or diesel powered (not hybrids):

1) Gas or diesel tanks by themselves don't burn. If you puncture them, they are semi-empty and bring an ignition source to them, gas will burn easily but diesel with great difficulty.
2) If either start burning with insufficient air, you get a (yellow - if you can see it) sooty flame. Such flames are usually not seen in spontaneous burning of vehicle videos, until after other components like interiors have started burning.
3) If your car is only gas or diesel powered, and shut off, and something with aerated fuel catches fire - how does more fuel get conveyed to the burning site? Capillary action? Is a pump still running? Why is the pump still running when the car is off?
4) If you get thermal runaway in a lithium battery, you get white smoke first and then (maybe) flames.
5) Many of the "burning" events you see in the linked video, and others on Youtube begin with white smoke being produced, and then a fire.
6) The flame test for lithium is red. In some videos of e-bikes/cars spontaneously burning you even see that the flames have a reddish hue.
7) What is the ignition source? If the car has just been turned off then maybe a hot engine (if it is a gas/diesel only-powered car spontaneously catching fire). But some of the cars had been off for some time. In which case the ignition source can only be electrical.

IMV I cannot reconcile the above line of thinking with cars spontaneously catching fire while off for some time. For a gas/diesel only-powered car to spontaneously catch fire, there are a number of factors which must be met:
1) Oxygenation of the fuel
2a) Initial transport of fuel to the burning site
2b) Continuous transport of the fuel to the burning site, while it is burning
3) Ignition of the fuel/air mixture

OTOH for an e-vehicle or hybrids' battery pack to catch fire, you only need a short circuit, e.g. physical damage to the battery causing an internal short circuit, an external one that bypasses any overcurrent protection system, etc.

 

[Rive]

Not sure why plug-in hybrids are not more popular

I too tend to wonder on that, and the best answer I could come up was, that it is seen as a compromise, so it is just not accepted as declaration of greenness: while on the other side it is seen as a traitor.

Would be nice to nice to see a bunch of PHEVs, powered from a 80% CO2 neutral grid and backed up with 50% renewable fuel (recovered from bio- and plastic waste or byproducts).
Such sweet dreams...

I read an op-ed recently, where the opinion was presented that focusing so heavily on individual carbon reduction is a bad thing (even calling it essentially a form of denialism, which is a bit much...).

I do not think that individual carbon reduction/awareness is a bad thing in itself, but it indeed has a part what makes the notion vulnerable to hijacking (just as it works for any ideal at the point when it becomes a public movement with a people to direct it). I still struggle to understand the whole 'save the planet' thing - not ruining it seems to be far more effective, no? Like that waste-gathering from the oceans with all that effort and so.

EVs may be a nice to have there, but their benefit vs a hybrid is pretty insignificant.

Link, fig. 6. around 3/4 of the page

If that happens, then the grid will peak at night, during the winter, maximizing the collective downsides of EVs and intermittent renewable energy.

Correct. And with that, all the benefit what could come with PV, will be thrown away too.

Then we'll be arguing if 3.0 COP heat pumps powered by natural 45% efficient natural gas power plants are better or worse than 95% efficient natural gas furnaces and nothing will have actually changed emissions-wise.

Still prefer to power the heat pump with a simple, 35% efficient gas engine and add all the waste heat to the COP

 

[BWV]

although looking at the IEA report, PHEVs appear to be outselling HEVs in Europe

 

[DEvens]

Full disclosure, I'm an employee of the nuclear industry.

I'm happy with every plug-in electric vehicle and every improvement of battery technology.

If electric vehicles starting charging at night using the off-peak load on the grid it would mean that the net load on the grid got flatter. Since most nuclear power plants prefer to run pretty much at 100% all of the time, this is very good for my industry.

Also, the better the batteries get, the more they can be used for load leveling. That seems to be just out of the range of commercial viability at the moment, but not by much. A factor of 2 in battery capacity would almost certainly move them over to commercial success. There are already battery farms that are used for short term peak handling. Time enough to ramp up a coal plant is basically what they supply. If battery farms could be made to handle even a few percent of the total load they could make the mid-day bulge smaller and the middle-of-the-night trough less deep. And that would be good for nuclear as well.

 

[Rive]

...they could make the mid-day bulge smaller and the middle-of-the-night trough less deep.

There is a way to make it even better. If you consider an adequate amount of PV capacity to supply the whole mid-day 'bulge' (with some reserves too: at least, on a sunny day), then what remains is a small part at morning, and a bigger part at the end of the day to be taken care by batteries (and conventional generation, of course - you can't get rid of those at this point anyway). That would at least double the daily use of the batteries.

 

[ZebulonPrime]

The Israely based company, Electreon, is building a smart road system that will interface with a receiver module. The receiver module will connect to the bottom of an electric car and will deliver power to the car as it passes over the section of road that has the smart grid built into it. This will system will allow for electric cars to have much larger ranges.

 

[Asymptotic]

Summary:: Are they really worth it?

Gas or diesel can sit happy in storage tanks for hundreds of years.

Maybe so, but probably not.

1. Long term diesel storage is less problematic than gasoline (especially gasoline-alcohol blends) because it consists of less volatile hydrocarbons. Even so, and even when treated with biocides and stored in full containers (to limit oxidation, and condensation), storage life is on the order of 5 years.
https://www.bp.com/content/dam/bp-country/en_au/media/fuel-news/long-term-storage-diesel.pdf

2. Gasoline is more volatile, and the lower molecular weight fractions will evaporate away. Gasoline is often blended with ethanol, and because alcohols are hygroscopic, moisture contamination becomes an even bigger issue. As with diesel, biocides are also indicated for long term gasoline storage.

3. Neither gasoline nor diesel fuel have been stored for hundreds of years, and stability over this time span is unknown. Underground storage tank leakage due to corrosion (mostly caused by water contamination) has been a big problem, so attention has to be paid to what the fuel will be stored in.

Doubt if it is practical, but very long term storage may be possible with a combination of lower temperature (see: Arrhenius equation) and tank venting through a regenerating desiccant bed (which ought to be good enough for a dewpoint of -40°C), or using a sealed tank with an inert atmosphere like argon in the headspace.

 

[anorlunda]

If battery farms could be made to handle even a few percent of the total load they could make the mid-day bulge smaller and the middle-of-the-night trough less deep. And that would be good for nuclear as well.

Have you seen what has been having in Southern California recently because of solar. The number of events with negative prices in the afternoons is increasing.

 

[Vanadium 50]

The number of events with negative prices in the afternoons is increasing.

You make that sound like a bad thing. Why? Lots of things have positive value at a certain place and time and a negative value at others. (Water, for example)

I think the fundamental issue is that solar's market value doesn't match its societal value: solar has positive value in late afternoon (when demand is high), negative value in early morning (when demand is low) and no value at night. However, society views it as a constant good.

I also think the whole idea of electric cars being "better" or "worse" includes relative value judgments. How does one rate the relative value of lower city emissions vs. global CO2 emissions vs. long-term disposal costs vs. virtue signaling, etc. I like my PHEV but would be the first to say it's not for everybody.

 

[mfb]

That's why it is so important to address the grid first.

If we try to comprehensively address one topic before starting with the next then we won't get much done in the 21st century. Ramping up production of electric cars, building the infrastructure for them and so on takes time. If they lead to lower greenhouse gas emissions today (and they tend to do) then increasing their fraction is good now.
Power plants can do much better exhaust filtering than cars and they have a higher efficiency, so even if you get the additional electricity from oil you end up with less pollution, and with pollution in areas with lower population density.

Have you seen what has been having in Southern California recently because of solar. The number of events with negative prices in the afternoons is increasing.

This is a projection from 2013? What is the y axis? Certainly not total demand. Demand minus renewables?

 

[anorlunda]

This is a projection from 2013? What is the y axis? Certainly not total demand. Demand minus renewables?

It is historical data. The Y axis is power delivered by the grid. It dips in the afternoon because of solar power produced and consumed inside the home that is not metered and that does not flow through the grid. So yes it is demand; demand for purchased electricity, distinct from consumed electricity. Total demand can no longer be metered.

You make that sound like a bad thing. Why? Lots of things have positive value at a certain place and time and a negative value at others. (Water, for example)

Negative prices destabilize the markets. I discussed this here
https://www.physicsforums.com/insights/renewable-energy-meets-power-grid-operations/

It is vital to electric reliability that we have a surplus of participants and suppliers. If they lose money, they withdraw and reliability of the grid is challenged. Electric utilities are obligated to supply electricity but no private investor is mandated to invest in electric power. Even public utilities depend on private investors to buy their bonds.

 

[mfb]

It is historical data.

Well, certainly not for 2020. Only 2012 and 2013 have "(actual)" in the description, that made me think the others might be projections from back then. And indeed: Various websites first had the graph in 2014.

 

[anorlunda]

Well, certainly not for 2020. Only 2012 and 2013 have "(actual)" in the description, that made me think the others might be projections from back then. And indeed: Various websites first had the graph in 2014.

Here's another source, published in 2016 that uses only history, not projections.

https://www.scottmadden.com/wp-content/uploads/2016/10/Revisiting-the-Duck-Curve_Article.pdf

In this report, ScottMadden analyzes average hourly production data from CAISO from January 2011 through June 2016 to understand if actual results align with the original forecast and what implications may tell us about what to do next. Our analysis confirms the duck curve is real and growing faster than expected.

Regarding EVs, it shows that in some locations, the lowest price power may be mid afternoon, rather than at night. That means that EV charging stations should be located at work. In work parking lots with thousands of cars, that's a big deal.

I had a discussion with the owner of the RV park where I live. He was upgrading service from 3.6 kW per site to 6kW. On the weekends, there is an average of 3 cars/trucks per site. I told him that if even half of of those cars/trucks become EVs in coming years, that the peak power needs of the park would increase to 16.5kW per site. If all become EVs, the peak demand becomes 27kW per site, and perhaps 40kW worst case when even more vehicles come on holidays. And that is not considering the possibility of those huge motor homes becoming EVs.

 

[neanderthalphysics]

Maybe so, but probably not.

1. Long term diesel storage is less problematic than gasoline (especially gasoline-alcohol blends) because it consists of less volatile hydrocarbons. Even so, and even when treated with biocides and stored in full containers (to limit oxidation, and condensation), storage life is on the order of 5 years.
https://www.bp.com/content/dam/bp-country/en_au/media/fuel-news/long-term-storage-diesel.pdf

2. Gasoline is more volatile, and the lower molecular weight fractions will evaporate away. Gasoline is often blended with ethanol, and because alcohols are hygroscopic, moisture contamination becomes an even bigger issue. As with diesel, biocides are also indicated for long term gasoline storage.

3. Neither gasoline nor diesel fuel have been stored for hundreds of years, and stability over this time span is unknown. Underground storage tank leakage due to corrosion (mostly caused by water contamination) has been a big problem, so attention has to be paid to what the fuel will be stored in.

Doubt if it is practical, but very long term storage may be possible with a combination of lower temperature (see: Arrhenius equation) and tank venting through a regenerating desiccant bed (which ought to be good enough for a dewpoint of -40°C), or using a sealed tank with an inert atmosphere like argon in the headspace.

OK thanks, I was thinking about the Strategic Petroleum Reserve but it seems the SPR stores crude, and not refined fuels.

Nevertheless venting of the more volatile fractions, and biological activity on the crude is still relevant to crude oil. How can crude be stored (by man, or geologically) in the long term? All the problems you present of biological activity, volatility and leaks/corrosion are present for crude storage as well as for storage of refined fuels. Obviously it was decided that these problems may be engineered out.

In any case, if you stuck petrol or diesel in a sealed, sterile container, they will last for hundreds of years, that's my point. Their energy content will remain. The fact that you may get biological activity on the fuel, loss of volatile components, absorption of water, leaks, etc. are issues that can be mitigated by engineering. The point is that fundamentally the physics and chemistry are on our side for long term storage.

I don't think you can say the same of charged lithium (or other) batteries.

 

[anorlunda]

How can crude be stored (by man, or geologically) in the long term?

You said it yourself, geologically. Leave it in the ground until needed.

 

[Rive]

Regarding EVs, it shows that in some locations, the lowest price power may be mid afternoon, rather than at night. That means that EV charging stations should be located at work.

At first sight it is both a very logical and very disturbing.
On the other hand, decent amount of PV capacity is already located 'at work', so the extra wire is just from the roof to the parking lot.
Cloudy days are still a problem, though.

 

[essenmein]

From a power train perspective full EV wins hands down. Three main reasons:
1) Battery charge to mechanical motion conversion efficiency is much higher (~80% vs ~20%)
2) Regenerative braking, EV can recoup some of the kinetic energy when coming to a stop vs burning 100% off as heat in brakes. More impact for stop and go vehicles than long distance driving.
3) 100% torque at 0rpm (unless you have a silly asynch machine).

EV are mechanically far simpler, which has down stream impacts like much lower maintenance requirements.

As far as pollution goes, if we ever get past this renewable thing and go 100% nuclear (no problem on cloudy days ), then IMO battery electric land vehicles start make sense for many applications, but if you have to have the grid scale BE storage (I have no nice words for this idea unless its some sort of flow battery, even then its an extremely tall order) competing for the Li as well then IMO there will be serious supply/cost issues as it rolls out globally.

Biggest thing we need to do though is basically standardize on one or two battery chemistries and base form factor for EV cells for volume production other wise recycling them at EOL will be a huge pain, we would need to be able to effectively recycle the lithium other wise in a few decades or whatever we'll be sitting there dumbfounded when we run out of the easy to get at stuff.

Maybe a curve ball could be nuclear->catalytic creation carbon based fuel from CO2 and H2O->combustion.

Even with the inefficiency, carbon based fuels still offer much higher energy density, 34MJ/l*0.2 is still a lot more than 2.4MJ/l *0.8... So if we could close the carbon cycle there with nukes then I'll happily continue listening to the howl of a straight 6 pushed to the red line even if it means I have to shift gears with a lever (how quaint).

 

[John Archer]

How long will an EV battery pack last? (my current ride is 15 years old, and going strong)
What needs to be done to dispose of EV batteries? How much can be recycled? (Iron and aluminum can be easiliy recycled)
While in many cities, the can make a bit more sense, in rural areas, they are very limited. Let me know when the Ice Road Truckers start running EV trucks.
How does weather affect performance? When it is -20 on a Wisconsin winter morning, will that EV have a similar range as on a 75 degree summer day?
How is the range affected when you need to crank the heat, on a cold day, or the AC on a hot one? (My current vehicle doesn't need to do anything extra to give me heat in the winter, and the AC has only a very minor effect on mileage)
I suppose one way to look at it is what happens if you accidentally run out of charge (or gas in a combustion engine car). Barring a tow, the regular car gets a couple of gallons of gas delivered and you are on your way in a couple of minutes. The EV, has a truck come out, with a diesel generator in tow,(ironic?) to charge the EV. Hopefully it doesn't take too long, and a charging station is nearby to finish the job.

Electric Vehicles are the future, the ones we have now are glimpses into what they can be. In a few decades they will be much better, they just aren't there yet.
Increase the amount of nuclear energy, and they start to make more sense.

 

[mfb]

Electric cars could charge other electric cars, just a matter of the right adapter. You would need to charge about as long as you drive to the nearest charger afterwards (assuming you get the electricity from a similar car), but that is not too bad.

Battery degradation doesn't seem to be a big issue for Tesla's batteries so far even after 250,000 km and 5 years, although we don't have data for 10+ years for obvious reasons: Graphs. And batteries are only getting better over time.

What needs to be done to dispose of EV batteries? How much can be recycled?

I generally prefer solid waste over a technology that blasts its toxic stuff directly into the air, as burning oil products does.

 

[DEvens]

The specific shape of the daily demand curve depends on many things.

In areas where there is a very warm summer, the demand tends to max out in mid-to-late afternoon, starting about 2PM to 3PM when kids start to get home, and parents get home to receive the kids. People get home, turn on the A/C, the TV, the stove, the computers, etc. and etc. It starts to fall again round about 9PM or so. In areas where there is less demand for A/C, the daily spike may be less pronounced. In areas where electric home-heating is a thing, there can be a big rise in demand from that when people get home and raise the thermostat, then it lowers when they go to bed, and turn down the thermostat.

It also depends on how much industry there is in the area. Industry tends to ramp up early in the morning, 6AM to 9AM, ramp down again late in the afternoon. Unless it's an industry that has multiple work shifts, in which case they can be flexible. Maybe it's worth paying the shift premiums to have the employees working at night in order to save electricity costs. Or some industries, such as aluminum smelting, have pulses of use that last for days then go low again.

 

[cosmik debris]

I suppose one way to look at it is what happens if you accidentally run out of charge (or gas in a combustion engine car). Barring a tow, the regular car gets a couple of gallons of gas delivered and you are on your way in a couple of minutes. The EV, has a truck come out, with a diesel generator in tow,(ironic?) to charge the EV. Hopefully it doesn't take too long, and a charging station is nearby to finish the job.

You could tow the EV part way to a charging station using regeneration to charge the EV part way.

Cheers

 

[member 656954]

It is good to question new tech, @neanderthalphysics, but honestly, on your superficial assessment, we'd not have moved to gas powered cars over horses (though, perhaps that would have been a good thing for us and the planet).

1) Energy to charge the batteries must come from somewhere.
If the source of the energy is nuclear, fair enough, the energy source has no carbon footprint. But if the source of energy is from an gas/oil power plant, you are exchanging one fossil fuel engine for another one. The power plant is probably more efficient especially if it is a combined heat & power plant, but still.

Battery electric vehicle (BEV) is an overall more efficient use of energy for personal transport than internal combustion (ICE) and even where BEV is fossil fuel powered, that means less overall fossil fuels are burned. But where BEV can be charged by renewable energy (RE) - and particularly locally by domestic solar power (PV) - then it is considerably more energy efficient and CO2 effective.

2) Batteries age
Gas or diesel can sit happy in storage tanks for hundreds of years. Batteries age; any charge held in them is lost over time and furthermore, over time they lose their maximum charge level.

I was not aware that anyone has demonstrated fossil fuels sitting in a storage tanks for hundreds of years (and fuel does eventually evaporate in any event), but irrespective, your point is a false equivalence. Yes, batteries lose their charge, but you're inventing edge cases if, for BEV, that makes a difference to the user. Do you expect any car to be left sitting for 'hundreds of years'? Of course not, and most drivers will never leave their car - BEV or ICE - undriven for an extended period sufficient that this is an issue. And if they do, then they should prepare their vehicle for the duration, as I had to do with my ICE car once when it went into storage for two years while I was working overseas.

The maximum charge level does need to be managed though, and dedicated battery management handles this in BEVs. Tesla has examples of 500,000 mile battery packs and recently announced intention of a 1 million mile battery pack, which from other evidence of battery robustness, seems a credible claim. We are finding that with careful power management, BEV batteries last a lot longer than most would have expected from their experience with phones and other Li-ion consumer electronic devices.

3) Safety of batteries
Batteries are basically sealed units with both the oxidizing + reducing agents mixed together in intimate contact. Which means the potential for a runaway reaction is there, waiting for a trigger. Gas or diesel tanks just contain fuel. Almost empty gas tanks contain fuel + oxidizer.

In any event, in an accident, the oxidizer for a gas/diesel powered car must come from the environment. For an electric vehicle, it is all there, pre- and well mixed. It will be very difficult to make the battery compartment of an electric vehicle immune to all sorts of damage which you might get in a conceivable lifetime - crushing damage, piercing, fires, etc.

Yes, this is an issue, however, real world statistics from BEVs on the road refutes your assertion of safety for typical road conditions, including accidents. You need to create extreme edge cases to support such a position, and for interest, look at the number of ICE vehicle fires per annum and compare that to BEV. Your ICE is a more dangerous place to be in a crash than a BEV on the basis of fires.

4) Lifetime carbon footprint of producing batteries
Has anyone looked at whether the lifetime carbon footprint of mining lithium and producing the batteries is worth it?

Yes they have and cursory research will highlight this. IVL recently updated their own 2017 research and it's a good news story. As more batteries are being manufactured, the per-plant capacity increases and per-battery pack CO2 goes down. Plus, more RE is being pointed at battery pack manufacturing, further reducing the CO2 load.

Also, while it's convenient to target lithium 'mining' (a subject many people have no idea mostly entails evaporation, not conventional mining) the same argument applies to fossil fuel mining. Fracking appears to cause microquakes, for instance, so avoiding them is surely a good thing.

At the macro scale, here's my general rebuttal to ICE pundits, applicable even if they don't believe in climate change:

1. Fossil fuels are not renewable, they will run out eventually, and we need them for more important manufacturing processes than moving individuals about for personal transport so BEV is a hedge to that future.

2. BEV does not inject particulate matter into the urban environment in the way ICE does, and cleaner air reduces health-costs that we are all paying for, directly and indirectly.

3. BEV is significantly quieter than ICE and significantly reduces noise stress across the board, another health cost benefit.

Irrespective of all the BEV vs ICE debate, we really need less people moving en mass in general, more public transport and ideally electrified, and lighter, smaller personal transport so a 'car' consumes considerable less energy per trip than they do now.

 

[russ_watters]

Another..uh..discussion we're having reminded me I never responded to this:

If we try to comprehensively address one topic before starting with the next then we won't get much done in the 21st century.

It wasn't my intent to imply that the grid conversion must be finished before we start electric car development. Grid conversion should lead - significantly - but at least the R&D and maturation of the products can certainly happen in parallel, and in particular if a guy like Elon Musk wants to use his own funds to do it, he can have at it. My concern is that the grid is being treated by many as an afterthought, or worse being approached in a fundamentally non-workable way, in my opinion.

This position does not apply to a nuclear power phase-out, which is at best a complete waste if even started before coal is eliminated.

Ramping up production of electric cars, building the infrastructure for them and so on takes time.

Yes, but I don't think it takes as much time as converting the power grid, which is one of the reasons I advocate a head start. It only takes about 2 years to develop and start producing a new car, people only keep new cars is about 6 years and the average car age in the US is 11 years. So if an electric car technology achieves a critical milestone or incentives/penalties mandate their proliferation we could have half the cars on the road be electric in about 15 years.

Also, I'm less concerned about infrastructure than you are, since the vast majority of recharging happens at home or at work.

If they lead to lower greenhouse gas emissions today (and they tend to do) then increasing their fraction is good now.

That's fair; my point is just that it isn't optimal. It isn't the quickest or cheapest or surest path to a given amount of carbon reduction. Since money is finite, using what we have to replace coal with nuclear should have the biggest bang for the buck.

 

[member 656954]

using what we have to replace coal with nuclear should have the biggest bang for the buck

Given the cost of nuclear and the deployment lag, that's a worse use of funds and works against your previous 'optimal' point.

The markets are saying that the biggest bang for buck is utility-scale solar and wind. Storage is the Achilles heel, and while Li-ion batteries are the current industry darling, higher energy density and / or lower cost per kWh is coming (Australian researchers have recently shown you can accommodate sulfer expansion in a lithium-sulfer cofiguration and that's more energy dense and likely cheaper) which will accelerate renewable energy by addressing the storage problem. Unfortunately, Li-ion is overshadowing flow batteries like Nant Energies Zinc-air that are well suited to grid applications, but as the need increases to plug the "sun ain't shining" gap, more solutions will be considered.

Vehicle-to-grid (V2G) is also mooted as a likely 'bang for buck' point because all those car batteries represent a huge energy sink (though I'm skeptical, unless battery electric vehicles (BEV) can be recharged in similar time to fossil fuel, I'm not sure drivers will want their 'tank' siphoned by their utility whenver).

Coal is being replaced right now, and not by nuclear...it's gas and renewables that are sending all those coal companies bankrupt.

 

[hmmm27]

When nuclear would otherwise be idle, use the power to suck Carbon out of the air.

 

[russ_watters]

Given the cost of nuclear and the deployment lag, that's a worse use of funds and works against your previous 'optimal' point.

The cost and deployment lag are misleading when looked at without considering the plant output because of how enormous the output of nuclear is compared with most solar or wind installations. What matters is the cost and time per unit of energy it will produce.

And both the time and cost of nuclear could be reduced substantially if people would just get out of its way.

The markets are saying that the biggest bang for buck is utility-scale solar and wind.

No they aren't; most new generation in the US is natural gas...or are you just referring to carbon free energy?

The markets aren't being motivated to consider the CO2 impact, nor are they currently structured to absorb the hidden cost of solar and wind's intermittency, which makes the produced power cost more than the amortized cost of the plant.

We can't let the markets keep running the way they are if we want a substantially carbon free grid. The only way to get there is to motivate construction of nuclear plants.

...which will accelerate renewable energy by addressing the storage problem.

No it won't: ignoring the intermittency problem is free; addressing it costs money. When forced to start addressing it, that will make solar/wind cost more, not less. Right now, those costs are borne by a hidden penalty on natural gas. It's a lot of the reason why the supposedly economical renewables have made electricity in Germany and California so expensive.

Coal is being replaced right now, and not by nuclear...it's gas and renewables that are sending all those coal companies bankrupt.

Yes; roughly 2/3 gas and 1/3 renewables. So do we want carbon free electricity or not?

 

[hmmm27]

roughly 2/3 gas and 1/3 renewables

Are the gas plants retrofittable to hydrogen and ammonia ?