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Can Electric Vehicles Be 'Environmental Villains'?

California Gov. Brown Holds Press Conf. On Expansion Of Electric Vehicle Market

Researchers from the University of Minnesota (Minneapolis) found in a new study assessing the life cycle air quality impacts on human health of 10 alternatives to conventional gasoline vehicles “that electric vehicles (EVs) powered by electricity from natural gas or wind, water, or solar power are best for improving air quality, whereas vehicles powered by corn ethanol and EVs powered by coal are the worst.” This study entitled “Life cycle air quality impacts of conventional and alternative light-duty transportation in the United States” and published in the renowned scientific journal ‘Proceedings of the National Academy of Sciences’ (PNAS) constitutes an important contribution to the debate over “environmental impacts of conventional versus alternative transportation options.” Importantly, the authors – Christopher W. Tessum, Jason D. Hill, and Julian D. Marshall – emphasizethat their “results reinforce previous findings that air quality-related health damages from transportation are generally comparable to or larger than climate change-related damages.”

Evaluating the air quality-related human health impacts of light-duty transportation in the US by comparing 10 options using alternative fuels – “including the use of liquid biofuels, diesel, and compressed natural gas (CNG) in internal combustion engines; the use of electricity from a range of conventional and renewable sources to power [battery] electric vehicles (EVs); and the use of hybrid EV technology” – the researchers findthat powering vehicles with corn ethanol or with coal-based or ‘grid average’ [i.e. projected 2020 US average electric generation mix] electricity increases monetized environmental health impacts by 80% or more relative to using conventional gasoline. Conversely, EVs powered by low-emitting electricity from natural gas, wind, water, or solar power reduce environmental health impacts by 50% or more.”

All scenarios in the graphic below represent increases in vehicle miles traveled and show concentrations of regulated air pollutants to increase in almost all scenarios.

Scenarios Depicting Changes in Annual-Average Concentrations of Regulated Air Pollutants

Roman EVs1

Source: “Life cycle air quality impacts of conventional and alternative light-duty transportation in the United States (PNAS) by Christopher W. Tessum, Jason D. Hill, and Julian D. Marshall. 

As for scenario H – ‘EV grid average’ – it is crucial to understand that here the underlying projected year is 2020 and that this scenario refers to US average electric generation mix with electric generation infrastructure for this period obviously not fully determined yet. This scenario, however, allows one to draw a conclusion not found in the study; namely, that EVs deployed in Germany and on the German ‘autobahn’ will do much better along all above metrics – resulting in a well-to-wheel emissions advantage over vehicles running on gasoline or diesel – given the underlying and current German energy mix in the wake of the ‘Energiewende’ – a transition away from fossil fuels towards renewable energy sources.

In an age where climate change and mitigation strategies to curb GHG emissions globally top political agendas – especially in the run up to COP21 in Paris 2015 – this research is a timely reminder to policymakers that transportation sector emissions are both substantial and harmful for humans as well as the atmosphere.

Granted, the link between motor vehicle emissions and respiratory illnesses is scientifically limited due to the complexity and difficulties in proper exposure assessments. Nevertheless, in 2012 greenhouse gas emissions from transportation accounted for about 28 per cent of total US greenhouse gas emissions, according to the US EPA. This made it the second largest contributor of US greenhouse gas emissions after the electricity sector with about 32 per cent.

Moreover, the above study combines “estimates of life cycle emissions [i.e., emissions from production (“upstream”) and consumption (“tailpipe”) of the fuel] with an advanced air quality impact assessment. This is significant because the general public often tends to over-simplify and equate zero-emissions with the widespread deployment of electric vehicles. The picture here, however, is much more complex as the new study above illustrates.

Even though it is true that electric vehicles (EVs) – including plug-in hybrid electric vehicles (PHEVs) – typically produce lower emissions than conventional vehicles, only all-electric vehicles have zero tailpipe emissions. In this respect, the US Department of Energy’s Alternative Fuels Data Center explains: “EVs and PHEVs running only on electricity have zero tailpipe emissions, but emissions may be produced by the source of electrical power, such as a power plant. In geographic areas that use relatively low-polluting energy sources for electricity generation, PHEVs and EVs typically have a well-to-wheel emissions advantage over similar conventional vehicles running on gasoline or diesel. In regions that depend heavily on conventional fossil fuels for electricity generation, PEVs may not demonstrate a well-to-wheel emissions benefit.”

Check out below this neat Alternative Fuels Data Center graphic and learn more about annual vehicle emissions in your zip code. roman EVs Compare Electricity Sources and Annual Vehicle Emissions1 (1)

Roman EVs Compare Electricity Sources and Annual Vehicle Emissions2

Source: Department of Energy’s Alternative Fuels Data Center; zip code used: Breaking Energy (10012) 

In addition, the difference between the least- and most-polluting power generation options for EVs – according to the study – “increases almost sixfold when air pollution damages are considered alongside climate impacts, instead of when climate impacts are considered alone.” As such, the benefits of “pairing EVs with ‘clean’ electricity’” seem apparent. These results, however, do not to suggest that “EVs are the best technology for every transportation need [but rather] an indication of how light-duty transportation fuels could shift to reduce or increase pollution, and [serve as] as an encouragement into the research of less polluting, more sustainable transportation options for the future,” the authors conclude. Read this interesting study in its entirety here.

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Engineer- Poet's picture
Engineer- Poet on Dec 25, 2014 4:31 pm GMT

The effect of the grid mix on the net emissions of EVs is a key issue in transportation policy.

One poorly-grasped detail is this:  the net cleanliness of electric propulsion can be changed long after the car is put into service.  The Leaf or C-Max Energi may not be all that wonderful on the grid mix at a particular place and time, but if the local grid mix is due to change for the cleaner then the car should receive credit.

There’s a factor which makes this even more important:  grid-interactive features of EVs, such as dynamic and schedulable charging, may be a factor to help drive the installation of emissions-free generation like nuclear.  Should EVs start helping to drive the economics of the grid, it will be a major change in the incentives.

Back about 10 years ago I calculated that the USA’s average power demand from an electrified ground-transportation system would be about 180 GW.  Openings for 180 GW of new generation would be an earth-shaking change in the electric market.

Robert Bernal's picture
Robert Bernal on Dec 25, 2014 4:28 pm GMT

They didn’t mention advanced nuclear which would be cleaner than all of the above?

Keith Pickering's picture
Keith Pickering on Dec 25, 2014 7:01 pm GMT

It’s also interesting to contemplate the kind of electricity that EV’s will demand. Because it’s likely that EV users will prefer to charge their vehicles at night, that will flatten the daily demand curve — which means that overall the demand will be for more baseload power, which means more nuclear.

Mark Heslep's picture
Mark Heslep on Dec 29, 2014 3:49 am GMT

PNNL researchers, Kinter-Meyer et al, did  work on emissions from EV electricity sourcs back in 2007, and to which this PNAS paper by Tessum et al unfortinuately make no reference. 

https://www.ferc.gov/about/com-mem/5-24-07-technical-analy-wellinghoff.pdf

Tessum et al calculate emissions only for PM and ozone, while PNNL calculated volatile gasses (e.g. benzene), CO, NOx, PM, SOx, and GHGs, all against the existing (2007) grid mix by both NERC electric region and the US in total.  For the US, for electric vehicles versus the existing combustion fleet, PNNL found similarly to Tessum et al, i.e that PM increases (by 18%) as does SOx (by 125%).  GHGs, CO, NOx, and VOCs all decline, with CO and VOCs nearly vanishing. 

Importantly, PNNL took another step and reported EV fleet emissions changes only in *urban* areas.  As one would expect, the results are substationaly better for EVs: *every* emission category declines strongly.  

Urban, US total, electric vehicle vs gasoline vehicle emissions ratio from PNNL’s Kinter-Meyer et al, Table 3:

  • VOC: 0.01
  • CO: 0.00
  • NOx: 0.10
  • PM10: 0.61
  • SOx: 0.19

Results vary a bit by NERC region though in all cases urban areas see declines for the EV fleet in all categories. 

Tessum et al address a mass transport model they use, but its impact in any detail is inpentratable in the paper or the figure 1 republished here by Kilisek.  Indeed, figure 1 does not resolve any major emissions sources like coal plants, though EIA/EPA maps make it clear the like of SOx emissions are several multiples higher than background in the vicinity of know coal plants. 

As urban areas are be definition the high population density areas, the increasing human harm forecast by Tessum et al for EVs, existing grid mix, are sharply in contrast with the conclusions from PNNL.

Clayton Handleman's picture
Clayton Handleman on Dec 29, 2014 6:17 am GMT

Server error, redundant posts.

Clayton Handleman's picture
Clayton Handleman on Dec 29, 2014 6:18 am GMT

Server error redundant posts.

Clayton Handleman's picture
Clayton Handleman on Dec 29, 2014 6:16 am GMT

EVs are a great match for wind power.  In some areas with vast wind resources, such as Texas, the wind blows mostly at night when the most car charging takes place.  If real time Time of Use metering is adopted, EVs could have price set points.  Consider a night where the wind blows some of the time but where there are some lulls.  During those lulls, a price signal would go out and the cars would see cost of charging going up and they would signal to cease charging.  As the wind picks up the price would change, going down.  Cars that had gone off line would now go back to charging.

Robert Bernal's picture
Robert Bernal on Dec 29, 2014 6:50 am GMT

Most people would have to charge their car every night, to get to work. I imagine a global grid is the best way to do renewable energy at large scale without fossil fuelled backup. And, there are other non carbon ways to back renewables, too

Nathan Wilson's picture
Nathan Wilson on Dec 29, 2014 8:57 am GMT

Right, each unit of night-time electricity which is used to charge an EV effectively combines with two units of day/evening electricity to form three units of baseload.  So in areas such as Georgia that are adding more baseload nuclear to the load-following-coal powered grid, EVs are effectively nuclear powered, hence zero carbon.  

On the other hand, in areas like North Carolina that are adding daytime solar to their coal powered grid, the EVs which use night-time charging are effectively coal powered.

To Clayton’s point, Texas is consistently adding windpower to their gas dominated grid, so I think it’s fair to think of night-charged EVs there as being power half by wind and half by fossil gas.

Mark Heslep's picture
Mark Heslep on Dec 30, 2014 12:50 am GMT

EVs are a great match for wind power. “

I don’t see any attempt in this PNAS study to resolve the details on the ground, such as the one you suggest, by-the-hour power type, or other details such as where the vehicle fleet is actually are located: predominately on the east coast, southern west coast, Chicago, and Texas.  Coal is not the dominate power source in any of those areas.  At the moment EVs are overwhelmingly concentrated in southern California.  I imagine the grid mix also changes with season, which would have some correlation with summer driving peaks.  

Mark Heslep's picture
Mark Heslep on Dec 30, 2014 1:15 am GMT

Back about 10 years ago I calculated that the USA’s average power demand from an electrified ground-transportation system would be about 180 GW.  Openings for 180 GW of new generation would be an earth-shaking change in the electric market.”

Or harder run existing generation if most of the charging could be forced to off peak (night) by some pricing mechanism.   The daily swing in PJM alone is almost 70 GW.   And the 2014 theoretical all-EV load seems to be a little less than your earlier estimate: 114 GW average using 3 trillion VMT/year at 3 miles per kWh. VMT changes a bit with season, but apparently less than 1%.

 

Engineer- Poet's picture
Engineer- Poet on Jan 1, 2015 9:53 pm GMT

EVs are a great match for wind power.

But not the reverse, I’m afraid.  EVs can do a pretty good job of evening out the short-term variations in wind, but wind isn’t a reliable source for supplying the needs of PEVs of the Energi, Volt and Leaf classes (with the Tesla you’re getting there, at least for commuting duty).  Such vehicles require charging very frequently (often on a daily basis, even more frequently if possible) and an energy source which often takes a few days off is just not capable of supplying what they need.

Clayton Handleman's picture
Clayton Handleman on Jan 2, 2015 3:30 pm GMT

If we were to freeze technology today I would agree with you but there are several factors which improve the picture over the 5 – 10 year timeframe. 

-Texas is expanding transmission access.  Presumably they will access their 50%CF resource that is virtually untapped to date.  This will reduce the intensity of the lulls.

– The giga factory is designed for 35GW cells and 50GW battery packs.  Tesla says that the GF is designed to provide batteries for 500,000 cars per year.  That means they expect EVs to go to 100kwhr per car in a mass market unit.  The Model S is 85kwhr so Musk, who has a pretty good track record, thinks we will have cars that can span a few days of commuting as the norm.  The new leaf is expected to double their range in the next year or two so trends are on track.

– Looking at Texas, which on an energy basis has sufficient wind resource to power the country, solar is a good match to compliment the wind power on down days.  (See Below) Ercot offers extensive wind data in Excel format so anyone can do the analysis.  A quick look shows a few notches of the kind you are talking about where wind dies to about 10% of capacity for a few days.  But solar is pretty robust during those periods.  So if solar is built out to compliment the wind power then charging during the day with solar may offer the load balancing.

– TOU metering would also kick the cost of electricity up during these lulls and reduce demand. 

Nathan Wilson's picture
Nathan Wilson on Jan 2, 2015 6:36 pm GMT

People are creatures of habit.  So this means you will have to train them to plug-in their EV both at night and during the day (and someone must pay for redundant charging infrastructure); worse yet, you’re not even going to guarantee that plugging-in will result in the vehicle being recharged (it depends on the weather).

There is also a question of whether Texans (and presumably their wind-rich neighbors in the central plains stretching to North Dakota) are sufficiently tolerant of the aesthetics of wind farms that they would be willing to see their wind farm land coverage increase by one or two orders of magnitude in order to export power to the rest of the nation.

The next question is whether people on the US east coast would be happy to out-source their power generation to Texas (along with the jobs and economic development that go with it).  Remember that the power flow would be essentially one-way, with wind or solar power from the East seldom being economically viable to sell to Texans.  Once the transmission is in place, even solar power from Texas and the Southwest would be half or less the cost of distributed solar in New York (with much less need for associated energy storage due to the sun setting later in the west).

I suppose these kinds of large behavior and attitude changes in the general public are possible, but I’ll believe it when I see it.

Engineer- Poet's picture
Engineer- Poet on Jan 2, 2015 6:55 pm GMT

I’ve successfully developed the habit of plugging my car in whenever I garage it.  I’ve even developed the habit of watching for outlets for opportunity charging.

This would be different if the likelihood of getting juice was as low as the capacity factor of your typical RE.  The rewards would be spread much too thinly.

Engineer- Poet's picture
Engineer- Poet on Jan 3, 2015 6:35 am GMT

-Texas is expanding transmission access. Presumably they will access their 50%CF resource that is virtually untapped to date. This will reduce the intensity of the lulls.

On the contrary, it will increase them.  Much or all of the lower Midwest is frequently under a single weather system at the same time.  If you increase the fraction of generation that is controlled by the weather, you increase the intensity of all associated variations including lulls.

– The giga factory is designed for 35GW cells and 50GW battery packs. Tesla says that the GF is designed to provide batteries for 500,000 cars per year.

500k vehicles per year is less than 5% of US LDV sales.

If the goal is to reduce petroleum consumption, Tesla-class vehicles are the least efficient use of batteries we have.  Stop-start comes first, then conventional hybrids, then plug-in hybrids.  Putting 8.5 kWh into 10 Energi-class PHEVs beats the tar out of 9 conventional cars and a single Tesla P85.  For that matter, 50 Prius-class hybrids with 1.7 kWh apiece beats the tar out of 10 Energi-class PHEVs and 40 conventional cars.  Elon Musk illustrates the endgame well, but as for the best pathway… I’m afraid that Toyota has already eaten his lunch.

– Looking at Texas, which on an energy basis has sufficient wind resource to power the country, solar is a good match to compliment the wind power on down days.

Living where I live, it would take perhaps 2 calm cloudy cold winter days to drive your solar-and-wind-powered house temperature below freezing.  That would become life-threatening in short order.

This is why I don’t particularly care what unreliable power sources match/offset other unreliable power sources.  I need something reliable, and if it’s cheap and clean enough I really don’t need anything else.  Gimme a nuclear plant for electric power for my PHEV and my ground-source heat pump; you can keep your greenie solar panels and wind farms.

Clayton Handleman's picture
Clayton Handleman on Jan 3, 2015 12:17 pm GMT

“On the contrary, it will increase them. “

No, the lulls will be reduced.  Increased CF usually comes by shifting the windspeed distribution curve to the right.  That then has the effect of shifting the graph that I posted UP.  In other words, the lulls may still be there but they are less intense and shorter in duration.

 

 

Clayton Handleman's picture
Clayton Handleman on Jan 3, 2015 1:36 pm GMT

If the goal is to reduce petroleum consumption, Tesla-class vehicles are the least efficient use of batteries we have.

That is an interesting point but not the one on the table.  I was looking at the question of intermittency.  You pointed out that multi-day lulls were problematic with Leaf (24 kwhr / 70 mile range) class vehicles but probably all right with Tesla class vehicles (85 kwhr  / ~ 300 mile range ). 

The trends are rapidly moving towards lower cost batteries and higher range.  A substantial fraction of EVs will be in the 100 kwhr class by 2020.  This, as you point out, will enable ridethrough of multi-day lulls.  Adding high CF wind will reduce the severity of the lulls.  And, if a good bit of solar is added, there can be load shifting to it in wind lulls.

The issue of number of EVs is a different question.  But your thinking seems flawed in this area.   You offer a fleet percentage that assumes the Gigafactory is the only source of vehicles and that EV growth will freeze in 2020. 

1) Many car companies are playing catch-up with Tesla.  So there will be far more than the 500,000 cars annually from Tesla.  Leaf and Chevy (volt) already build more cars annually than Tesla and there are a number of others that are nosing into the space.

2) Tesla has three additional sites permitted and ready to build on.  Based upon press reports suggesting a vision for many gigafactories, I think that they full well plan to build on those sites. 

Low gasoline prices will slow the mainstreaming of EVs but whether the tipping point is 5, 10 or 15 years from now it is coming and it will enable considerably higher penetration of renewables than the current perceived limit of about 20%.

BTW, EVs will also be great for nuclear.  Nuclear does not like to ramp up and down.  Variable charging schemes, whether under utility control or market driven will smooth the load.  That also solves the load intermittency problem that limits penetration of nuclear power.

 

 

 

 

 

Clayton Handleman's picture
Clayton Handleman on Jan 3, 2015 1:52 pm GMT

“To Clayton’s point, Texas is consistently adding windpower to their gas dominated grid, so I think it’s fair to think of night-charged EVs there as being power half by wind and half by fossil gas.”

The load shift possible with EVs reduces the need for fuel switching.  Texas wind is night peaking, and the current load is day peaking.  By shifting load to night time, the fraction of wind to other improves. 

 

Nathan Wilson's picture
Nathan Wilson on Jan 3, 2015 3:46 pm GMT

EVs will also be great for nuclear.”

That’s a good point.  In fact, real-time variable time-of-use metering is not needed, but only simple night-time discounts.  The user can simply set his charger for a fixed start-time, and know with certainty that the car will be fully charged in the morning.

That means that users need not over-size their batteries for the benefit of the grid.  They can buy cars with minimum battery sizes, say 150 miles range; then 10-15 years down the road, when the battery range has faded to 75 miles, the car is still useful.  This saves cost, vehicle weight, and volume.  It also means that Tesla-sized 300 mile range batteries may remain in the luxury niche, and that grid storage repurposing of used car batteries won’t happen as they will be driven into the ground.

Clayton Handleman's picture
Clayton Handleman on Jan 3, 2015 4:21 pm GMT

From a life cycle cost perspective, larger batteries do not add cost.  They need less frequent charging and therefore last longer.  Wind will be a valuable contributor to the energy mix.  EVs with load shifting allow for higher penetrations without grid disruption or destabilization.  And since much of the wind is night peaking they will do so without requiring gas backup as you suggest.   

Thorium reactors may or may not prove to be a good way to go but they are 15 years away at best.  It is pathetic that, even in this somewhat progressive forum, there is not an open and thoughtful discussion of the technical challenges of Thorium reactors.  Shall we wait around for a maybe when we could be adding wind power to 15 – 25% which all informed folks agree is doable with little or no significant destabilization issues?

Light water reactors have proven the critics to be right.  No waste disposal solution, escalating costs and costs forced upon rate payers and tax payers rather than willing investors. 

Nuclear will continue to get intense pushback until the nuclear folks own their failings and address the challenges in a transparent and public manner. 

 

 

Mark Heslep's picture
Mark Heslep on Jan 3, 2015 7:45 pm GMT

Stop-start comes first, then conventional hybrids, then plug-in hybrids.  Putting 8.5 kWh into 10 Energi-class PHEVs beats the tar out of 9 conventional cars and a single Tesla P85.  For that matter, 50 Prius-class hybrids with 1.7 kWh apiece beats the tar out of 10 Energi-class PHEVs and 40 conventional cars.  Elon Musk illustrates the endgame well, but as for the best pathway… I’m afraid that Toyota has already eaten his lunch.”

Great analysis EP.  Reminds me of attempts to disabuse my kids from trying to win the game with a Queen alone in the first couple moves. 

One possible caveat is cost.  That is, if the goal is to reduce petrol consumption given a fixed amount of dollars in a given time frame, then building dual drive train vehicles carrys an overhead cost that is vulnerable to single drive train EVs, eventually, especially since the hybrid with a small combustion engine requires all of the components of the combustion-only vehicle (starter and ignition systems, transmission, exhaust system, oil/water/fuel pumps and filters, fuel tank, big heat rejection system, etc). 

Today, 9 PHEVs + 1 ICE is clearly less expensive than 10 EVs and Musk loses.  Tomorrow, maybe not. 

Engineer- Poet's picture
Engineer- Poet on Jan 3, 2015 8:29 pm GMT

From a life cycle cost perspective, larger batteries do not add cost. They need less frequent charging and therefore last longer.

Two words:  “calendar life“.

Wind will be a valuable contributor to the energy mix.

Assertion without evidence.  So far, wind has only “succeeded” on major grids when it has been subsidized, mandated or both.  You yourself noted that wind often peaks when demand is well off-peak, so you call for new loads to make it useful… admitting implicitly that it’s not nearly so useful today.

Wind’s current use is as a political weapon against nuclear power, which you implicitly admit here:

Light water reactors have proven the critics to be right. No waste disposal solution, escalating costs and costs forced upon rate payers and tax payers rather than willing investors.

Two comments before you were talking nuclear up, then you turned to attack it.

There are no technical problems with nuclear power.  Cost escalation has been driven by political actors, such as the NRC mandating redesign of the containment buildings at Vogtle 3 & 4 despite the design being finalized and contracts signed.  Yucca Mt. meets all the technical requirements for permanent disposal; the NRC had to admit as much when it was forced to finally release its reports.  (Not that we need to; “spent” LWR fuel still has 95% of its original energy in it, and there are reactors capable of unlocking that potential if we only have the will to build them.  Fission products become less radio-toxic than uranium ore in about 500 years.)

Nuclear power is anathema to “big Green”, because it threatens the rent streams of fossil-fuel interests.  This is why climate scientists are increasingly vocal advocates of nuclear power, while the donor-driven Green organizations are steadfastly opposed.  Those same donor-set agendas push wind specifically because it can never replace fossil fuels.  If “big Green” turned around and pushed all carbon-free energy regardless of source, the industrial societies would have grids like France, Sweden and Ontario.  They’d have next to no use for coal, and much less for natural gas.  Peabody Energy, Qatar, and Russia would all be in a world of hurt.  This is why they’re all pushing anti-nuclearism outside their own borders:  it protects their markets.

Engineer- Poet's picture
Engineer- Poet on Jan 4, 2015 4:42 am GMT

That is an interesting point but not the one on the table. I was looking at the question of intermittency.

All right then.  Suppose Tesla builds Gigafactories at all 4 sites and produces 50 GWh of battery packs per year at each one.  That is 200 GWh/yr total.  Average generation on the US grids is about 450 GW, so one year’s battery production would support the grid for (200 GWh / 450 GW) = 26 minutes 40 seconds.  That is assuming that it starts from full charge and is fully devoted to dealing with intermittency, with no other functions to perform like moving cars around.

Do you begin to grasp the COLOSSAL size of the intermittency problem?  It is not something you can solve with just a snap of your fingers.  Running the US grid on wind and solar would require dozens of TWh of storage.

If we are trying to solve the problem of petroleum dependency, 4 Gigafactories would make a major dent.  200 GWh/year over 14 million vehicles per year in the US market is about 14 kWh per vehicle.  That is enough to make each one a Volt-class PHEV.  If they achieved 4x the average fuel economy of the current sales mix (about 26 MPG), liquid fuel consumption would fall by almost 40% in 5 years.  They’d do well as V2G devices also.  14 million vehicles * 3.3 kW/vehicle is a potential 46.2 GW of controllable demand.  This would not do much for major intermittent supplies, but it would be more than enough to provide the margin of regulation against other fast-varying loads compared to slow-ramping generators.

Musk may have problems getting raw materials.  Typical Li-ion cells today require in excess of 1 kg of lithium per kWh of capacity.  Making 200 GWh/year of cells would consume in excess of 200,000 tons of lithium against worldwide reserves estimated at 13 million tons.  More to the point, 200,000 tons is about 6 times the world’s production of lithium in 2011.

A substantial fraction of EVs will be in the 100 kwhr class by 2020. This, as you point out, will enable ridethrough of multi-day lulls.

That part of the EV fleet would be able to.  The rest of the grid could not, and the storage on EVs would be totally inadequate to do much about it.

BTW, EVs will also be great for nuclear. Nuclear does not like to ramp up and down.

To be more accurate, solid-fuel thermal-spectrum reactors have issues with xenon poisoning if they ramp down for very long and then try to ramp up.  This does not apply to liquid-fuel reactors (which purge the xenon) or fast-spectrum reactors.

Since reactors are typically refueled on a schedule rather than when the fuel runs out, ramping them down doesn’t save anything.  It makes far more sense to run them flat out for most of a run and use excess electricity or heat for other purposes.  One possibility is the production of anhydrous ethanol by pervaporation of water through semi-permeable membranes.  Diverting 1 GW(th) out of 3.4 GW(th) would evaporate about 980 lb/sec of water at the sea-level boiling point.  If this started from a 5% w/w mixture of ethanol or other liquid fuels in water, you’d get about 49 lb/sec of product or about 100,000 liters (~2700 gallons) per hour.  2700 gph * 8 hours = 216,000 gpd.  400 plants * 216kgpd = 83 million gpd total.  Total US consumption of motor gasoline is about 9 million barrels (~380 million gallons) per day, of which 83 million gallons is almost 22%.  Convert the fleet to PHEVs, and the off-peak heat in a fully-nuclear US grid could provide the process heat for the remaining requirements from biofuels, carbon-free and without other air emissions.

Note that pervaporated water (steam) carries plenty of energy and would itself have a multitude of uses.

 

Robert Bernal's picture
Robert Bernal on Jan 4, 2015 6:21 am GMT

It’s not quite thorium but this MSR design is all we need to conquer!

http://transatomicpower.com/white_papers/TAP_White_Paper.pdf

Engineer- Poet's picture
Engineer- Poet on Jan 4, 2015 6:22 am GMT

No, the lulls will be reduced. Increased CF usually comes by shifting the windspeed distribution curve to the right.

Rod Adams noted a 2-week near-total wind outage in the BPA early in 2014; he found another week-long one a few months ago.

The theoretical power available from a device in free-stream flow of air moving at uniform speed v is 8/27 ρAv³.  That v³ term is the killer.  You can undersize your generator to get greater capacity factors, but it only takes a 21% drop in wind speed to cut the available power by half.  At half speed, available power has fallen 87.5%.  There is no way to finesse this with machine design; you can’t get more power out of the airflow than physics put into it.  This means that those lulls may have slightly different slopes and not stay at the bottom quite as long, but outages lasting 1-2 weeks are still going to happen.  This is why the capacity value of wind is very low, and it cannot replace conventional generation; it’s a fuel-saving measure, not a way to upend the existing order and eliminate fossil fuels.

Undersizing generators means you get less peak and average power out of the same investment in towers and rotors.  I’d like to see what the industry does to create value in the absence of a PTC which subsidizes generation even when nobody needs power.

Clayton Handleman's picture
Clayton Handleman on Jan 4, 2015 3:22 pm GMT

“Rod Adams noted a 2-week near-total wind outage in the BPA early in 2014; he found another week-long one a few months ago.”

The majority of high penetration renewables scenarios include HVDC to links to decorellated sources making the statistical probability of a 2 week drop out vanishingly small even for relatively poor quality wind resources like that of BPA. Of course, the reason BPA is a good place to develop a moderate wind resource is because of the extensive hydro.  The quality of the wind there is not typical of the much better wind resource in the great plains. 

Adam’s piece is the poster child anti-wind study supporting the pro-nuclear, anti-renewables echo chamber that TEC comments section is rapidly becoming.  BPA is a moderate wind source with limited geographic extent.  Hardly the scenario evisioned by NREL studies such as EWITs (30%) or the Renewable Electricity Futures Study (90%).  You, no doubt, have ignored those authoritative studies and my frequent posting of links to wind resource maps and other data showing vastly more productive sites in the great plains.

In this thread I posted a link to ERCOT data that showed maximum lulls in that relatively small geographic area as maxing out at a few days.  If linked via HVDC to broader areas then more decorrelation and the floor would raise.  I do not advocate a ‘wind only’ or ‘solar only’ solution.  I think that a mix of solar, wind, Hydro linked with HVDC and stabilized with market based TOU metering that load shifts EVs offers an opportunity for substantial penetration of renewables.

During that time, research on advanced reactor technology should be expanded and an orderly program for phaseout of light water reactors should be developed and funded.  If done wisely over a 20 year time frame, we can accomplish the following:

– Assess whether high penetration renewables can be done stably

– Find out whether battery technology will continue rapidly down the experience curve allowing for mainstreaming of EVs

– Determine whether market driven load shifting will work well and reliably

– Determine whether good advanced reactor technologies can be scaled up safely reliably and cost effectively.

The comments section has become monotonous self congratulatory cheerleading for nuclear power exclusively.  There is little productive forward motion in the discussion.  Instead of focussing on the Thorium propoganda I would like the supposedly knowledgable people on the board to discuss what the barriers to Thorium are.  Clearly they are not strictly political.  If it really were as easy as some say, then we would be doing it.  As Bas has pointed out, there are challenges.  Bill Gates (a pretty smart guy with the resources to dig into the topic) is not spending his money on the traditional Thorium reactors.  Why? 

 

 

 

 

Nathan Wilson's picture
Nathan Wilson on Jan 5, 2015 1:01 am GMT

“…the poster child anti-wind study supporting the pro-nuclear, anti-renewables echo chamber…”

Clayton, there are two sides to every polarizing issue!  If you look back at the major clean energy studies made by scientific groups such as NREL’s 20% Wind, NREL’s EWITS, NREL’s RE Futures, and the newer DDPP (supported by LBNL and PNNL) what you find is descriptions of blended clean energy grids that combine renewables with LWR-based nuclear (often with the warning that removing the nuclear makes the cost go up).  

But when we read publications (including those on TEC) by green groups, what we find is an almost universal call to remove the nuclear, often with a claim that we’ll save money by doing so.  When other justification for a nuclear phase-out is given (e.g. health and safety benefits or even CO2 reductions), again the technical liturature generally predicts the opposite outcome.

So is it such a surprise that readers familiar with the technical reports are tempted to point out the errors they see?   It takes more than just optimism to believe in an all-renewable future, it requires a willingness to ignore science, and I don’t think that is something we should cultivate.

Why is it so hard for renewables’ supporters to do their cheering without hating on nuclear?  That’s the real issue.  The nuclear-hate is not a rational reaction to an energy source that prevents air pollution and CO2 emissions on a massive scale, even with schedule slips and cost over-runs, and is not an appropriate reaction to industrial accidents that have zero fatalities.  The hate (apparently) comes from another place, a place of fear and propaganda; and it can only be addressed with information and dialogue.

Engineer- Poet's picture
Engineer- Poet on Jan 5, 2015 3:59 am GMT

The majority of high penetration renewables scenarios include HVDC to links to decorellated sources

Which happens to be major infrastructure that does not exist yet.  There are not even rights-of-way procured, which is a process that takes many years and is very costly.

How distant do you have to be to achieve decorrelation?  That’s not even fully adequate; what you need is anti-correlation.  This is why the SPS concept put solar collectors in space; there were no weather-related outages, and the flights through shadow around the equinoxes were brief and occurred at local midnight.  Strongly correlated they were, but when they happen at scheduled times near minimum daily and seasonal demand they are much easier to deal with.

the reason BPA is a good place to develop a moderate wind resource is because of the extensive hydro.

And it’s probably not good to develop very much wind where there are no such backing sources like hydro.  You run into diminishing returns much faster.

Adam’s piece is the poster child anti-wind study supporting the pro-nuclear, anti-renewables echo chamber that TEC comments section is rapidly becoming.

Rod Adams makes no bones about being an advocate for nuclear energy.  As for TEC becoming one-sided, perhaps you’d like to explain why 25 years of effort gave Denmark just 33.8% of its electricity from wind in 2013 at one of the highest electric rates in Europe (and a whopping 48% from coal), while France leapt to ~80% of its electricity from nuclear power over a ramp lasting less than 15 years and now has rates among the cheapest.  On what grounds can you claim the French example is inferior either for people or the environment, and push the Danish one in its stead?

You, no doubt, have ignored those authoritative studies

I’ve been looking at the actual examples and how the much-vaunted studies fail to account for the real-world failures.  Analysts can write ideology into their assumptions, or simply make mistakes; nature cannot be fooled.

During that time, research on advanced reactor technology should be expanded and an orderly program for phaseout of light water reactors should be developed and funded.

In other words, phase out LWRs with no guarantee that any other technology would ever be built.  You could not be more blatantly biased.

Keith Pickering's picture
Keith Pickering on Jan 5, 2015 5:38 am GMT

Once you reach the point of wheeling large amounts of wind power across the country, wind is no longer cheap. And that’s not just because of the cost of building the powerlines (which are substantial), but even more importantly it’s because that solution only works if the other part of the country, from which you’re drawing your wind power during the lulls, has overbuilt its wind enough for its own needs and for your local needs on windless days.

Which means that you have to overbuild your wind too, so that you can return the favor when their wind dies.

The result of this is massive curtailment of wind most of the time, because most of the time those overbuilt turbines will stand idle. And there goes your wind CF, right down the tubes, and cheap windpower along with it.

This is exactly why DDPP found that the median high-renewables pathway was four times more costly than the median high-nuclear pathway — even though the high-nuclear pathway also foresees massive new builds in wind and solar, that pathway was careful to keep grid penetration of renewables below the curtailment point. Which means, roughly speaking, that weather-dependent renewables should not have grid penetration greater than their capacity factors.

Clayton Handleman's picture
Clayton Handleman on Jan 5, 2015 5:30 am GMT

Nathan,

Thanks for your thoughtful response. 

 

 

Engineer- Poet's picture
Engineer- Poet on Jan 5, 2015 7:48 pm GMT

Silicon is an electrode material which takes up lithium ions (sulfur is another).  Neither is a replacement for lithium.

Mark Heslep's picture
Mark Heslep on Jan 6, 2015 12:20 am GMT

The side topic of lithium requirements for EVs  and availability of mined lithium has come a few times and I thought it might be helpful to review the background.

While lead based batteries must have a maximum energy density (energy/mass) based on basic electrochemical cell potential of several kilogram per kWh, the maxium density of lithium batteries is considerably better. The cell voltage of LiCo batteries (as used by Tesla) is 3.7V, so the energy density per mole is 3.7 eV * Avogadros constant, or 0.36 MJ, or 0.1 kWh per mole of Li.  With a molar mass of Li of 7 gm/mole: 0.07 kg Li per kWh (ideal).   

The 2011 worldwide annual production of 34 thousand tons Li then allows for a maximum or 5.7 million Tesla Model S (85kWh) batteries per year. 

As for practical batteries, an ANL report  (Table 2) breaks down a typical EV battery pack by mass, finding 33% cathode material (LiMn2O4 in this case).  The cathode is in turn 1.7% Li, i.e. the Li mass is  0.6% of the total battery. 

 

 

 

Clayton Handleman's picture
Clayton Handleman on Jan 8, 2015 1:51 am GMT

“Musk may have problems getting raw materials.”

Thanks for the link.  I don’t think Lithium will be much of a problem.  Until recently it doesn’t appear that they were looking very hard for it.  In recent years the identified lithium resources have increased by a factor of 3 and the US identified resrouces have increased by over 5X.  This post graphs the increase in Identified Lithium resources and shows an encouraging trend.

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