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Range anxiety? Today's electric cars can cover vast majority of daily U.S. driving needs

Posted on 5 September 2016 by Guest Author

By Jessika E. Trancik, Associate Professor in Energy Studies, Massachusetts Institute of Technology

This article was originally published on The Conversation. Read the original article.

Electrifying transportation is one of the most promising ways to significantly cut greenhouse gas emissions from vehicles, but so-called range anxiety – concern about being stranded with an uncharged car battery – remains a barrier to electric vehicle adoption. Is range anxiety justified given current cars and charging infrastructure?

It’s a question my research group and I addressed in a paper published in Nature Energy, by taking a close look at this problem with a new model.

Specifically, we asked: When looking down on the geographic area of the U.S. from a bird’s-eye view, how many personal vehicles on the road daily could be replaced with a low-cost battery electric vehicle (EV), even if daytime charging isn’t available? Our analysis is, to our knowledge, the most expansive yet detailed study to date of how current and future-improved electric vehicle technology measures up to people’s energy-consuming behavior.

We found nearly 90 percent of vehicles on the road could be replaced by a low-cost electric vehicle available on the market today. What’s more, this number is remarkably similar across very different cities, from New York to Houston to Los Angeles. That is, there is a high potential for electrification of cars in both dense and more sprawling cities in the United States.

To realize this potential, however, the needs of prospective electric vehicle drivers have to be met on all days, even high-energy ones, such as days that require long-distance travel.

Two key innovations can enable this. The first is to predict the days on which drivers are likely to exceed the car’s range, which our model is designed to do. And the second is institutional or business-model innovation to provide alternative long-range vehicles on those high-energy days. For example, conventional cars, and eventually low-carbon, long-range alternatives, might show up at a user’s door at the click of a button. This need may last for some time even as battery technology improves and charging infrastructure expands.

Vehicle range is not a single number

An electric vehicle’s range is typically thought of in terms of a fixed number, but the number of miles covered on a single charge changes with factors including driving speed and style, and outdoor temperature. To understand the range of a car, we need to look beyond the car itself to how people are behaving.

Over the last four years in my research group, we’ve built a model (called “TripEnergy”) of the second-by-second driving behavior of people across the United States, how they are likely to use heating and cooling systems in their cars, and how various electric and conventional vehicles would consume energy if driven in this way.

General Motors is developing the all-electric 2017 Chevrolet Bolt, which is designed to have a driving range of about 200 miles. General Motors

This approach gives us a probabilistic view of electric vehicle range. For example, for the Nissan Leaf, we find that 74 miles is the median range – based on driving patterns, half of the cars on the road in the U.S. would be able to travel this far, and half would not. (A Ford Focus electric performs similarly.) There is a distribution in this range, which demonstrates how widely actual performance can vary. We estimate, for instance, that five percent of 58-mile trips could not be covered on one charge, and five percent of 90-mile trips could.

Evaluating electric vehicle technology against driving behavior

With the TripEnergy model in hand, we asked how many cars on the road could be replaced with a low-cost electric vehicle available today. We considered a case where drivers can charge only once daily: for example, at home overnight. This allowed us to study a situation where only limited changes are needed to existing public charging infrastructure and cars can use power plants that would otherwise sit idle overnight.

We found that, given how people are driving across the U.S., 87 percent of cars on an average day could be replaced with a current-generation, low-cost electric vehicle, with only once-daily charging. This is based on the driving behavior of millions of people across the U.S. across diverse cities and socioeconomic classes.

Switching from conventional to electric vehicles for those cars would cut emissions by an estimated 30 percent, even with today’s fossil fuel-based supply mix. In total, the trips taken by those cars represent roughly 60 percent of gasoline consumption in the U.S.

This large daily adoption potential is remarkably similar across both dense and more sprawling U.S. cities, ranging from 84 percent to 93 percent.

While it’s true that people behave differently across cities – in how they use public transport, whether they own a car, and how often they drive the cars they own – when they do drive, we found that a similar number of cars in different cities fall within the range provided by a low-cost electric vehicle.

Returns on technology improvement

What if batteries improve, and allow for longer driving range for the same cost as current-generation lithium ion batteries?

The federal research agency ARPA-E has set a target for batteries to store roughly two times more energy by weight than today’s batteries in electric vehicles. If that technical target is reached, we estimate that the 87 percent daily adoption potential estimate would rise to 98 percent, and the gasoline substitution potential would rise from 61 percent to 88 percent. The 2017 Chevy Bolt and 2018 Tesla Model 3 are expected to achieve roughly similar increases in potentials at an increased cost compared to today’s Nissan Leaf, though these costs are still close to the average cost of new cars. The Tesla Model S travels even further but costs significantly more.

Even with substantial battery improvements, however, other types of powertrain technologies will be needed to cover those days with the highest energy consumption. This need may persist for some time, even with expanded charging infrastructure, due to a small number of very high-energy days.

The upshot on range constraints

For people to overcome range anxiety and feel comfortable buying an electric vehicle, they need to know their needs will be met on all days, including high-energy days. Predicting when this will occur – and in advance when buying a vehicle on how many days this will occur – is something that our model is well-suited for.

The expansion of car-sharing services makes it easier to get a car for a long-distance trip. davereid/flickr, CC BY-NC

Our model can, with limited input on travel distance, time and location, predict the probability of exceeding the car’s range, and point to days where drivers need to turn to other, longer-range cars, for example, within households, or even within communities and through commercial car-sharing programs. The results also shed light on the quantity of long-range cars that would be needed at the population level, a gap to be filled by private sector innovation as well as national and local policy.

Reasonable financing to help distribute the upfront costs over the car’s lifetime and increasing the opportunities for charging, even if only once daily, would also encourage EV adoption.

In all, our analysis shows that current electric vehicles can meet most daily driving needs in the U.S. Improved access to shared, long-range transport, alongside further-advanced batteries and cars and decarbonized electricity, provides a pathway to reaching a largely decarbonized personal vehicle fleet.


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Comments 1 to 34:

  1. Associated with the range of electric vehicles is the more important need for electricity generation to be better than natural gas burning and plug-in infrastructure to be built as a public utility (not expecting a popularity and profitability motivated system to rapidly develop the required result).

    Electric cars do make sense as long as the electricity generation to power the vehicle produces less CO2 than the burning of natural gas to generate electricity.

    An eia presentation indicates Natural Gas generation produces about 0.55 kg of CO2 per kWh but the total amount of CO2 would be higher due to electrical delivery losses and CO2 or equivalent, like fugitive methane emissions, generated in the production and delivery of the natural gas.

    I chose to buy a hybrid because I live in Alberta. In Alberta in 2015 more than 50% of the electricity generation was coal fired (Alberta Government Report for 2015)

    Electric vehicle efficiency ranges from 20 to 25 kWh/100 km. If the generation was from natural gas, that would be a minimum of 11 to 14 kg CO2/100 km (higher when other CO2 impacts are added). Alberta's average would be poorer than that. At 50% coal (0.95 kg CO2 / kWh) and 50% natural gas the result would be a minimum of approximately 0.75 kg of CO2 / kWh. That means a minimum of 15 to 19 kg of CO2 / 100 km (actual amount higher due to distribution losses and other considerations).

    Burning gasoline generates 2.3 kg CO2 per litre. With a 40% bump of emissions for extraction, refining and transportation of the fuel (what seems to be a reasonable value based on many different values provided by many different sources) there would be 3.3 kg of CO2 per litre. And my hybrid is running 4.7 l/100 km combined city and highway use (in the city I am getting close to 4.2 l/100 km). So my hybrid use generates a total of 15.5 kg CO2/ 100km (only 14 kg/100 km in the city).

    Another important consideration I had to make was that Alberta currently lacks decent electric vehicle plug-in locations for long distance travel (or for in city travel). And in Alberta most day-trips to destinations near the city of Calgary or Edmonton would be a round-trip that is well beyond 100 miles total distance (many local day-trips would be longer than 200 miles round-trip).

    So the focus needs to be on vastly improving the elctricity generation in many regions. And vastly improving the infrastruction for plugging in when travelling outside of cities in many regions. That will take leadership that many regions are unlikely to have a clear majority vote to support. That may require external motivation on those regions to "Do Better than their population would prefer to do".

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  2. Electric cars might not emit CO2 when driven, and electricity from renewable sources can be used to recharge them, but how much CO2 is emitted in their manufacture?  I have read elsewhere that there are significant emissions involved in the manufacture of an electric car.

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  3. Digby.

    Most cars are considered to have an embodied energy content equal to severla years of driving. Electric cars would be no different. Whether electric cars particularly have a higher content, dunno.

    The point hopefully is that as we transition to zero-carbon technologies, the production processes behind car (and everything else) manufacturing also become low/zero carbon.

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  4. A car that only works for you 87% of the time is not going to work for a lot of people. It certainly wouldn't work for my family. We use a pretty common strategy (I think) of one small, fuel-efficient vehicle and one larger vehicle with poor mileage. Can an electric replace either? No! It can't replace the Prius because range is critical for this vehicle as most of the miles come from road trips far beyond an electric's range. And it can't replace the truck because the entire purpose of the truck is to haul stuff.

    The problem I see with electrics is that they leave a gap in a two-card household. If your other car is small and fuel efficient, you have no ability to haul. If your other car is heavy duty, you have no vehicle that can cheaply take you long distances. Additionally, if you are in a one-car household, an electric would leave you with both of these gaps rather than just one, as a non-electric would.

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  5. The 'power plant CO2' and 'manufacturing CO2' issues are both red herrings. Certainly we should continue to improve CO2 emissions in both areas, but even if we didn't neither would be a valid argument against electric vehicles.

    As Glenn noted, manufacture of all cars involves CO2 emissions. The primary difference being that electric cars replace the internal combustion engine with a larger rechargeable battery pack. The primary source of CO2 emissions from car manufacture is due to the use of steel (commonly made by heating iron oxide and carbon, with CO2 as a byproduct)... and the internal combustion engine is a huge block of steel. Nothing in the electric vehicle battery pack comes close to requiring similar emissions. However, since many of the materials used in rechargeable batteries are currently mined in China, using coal power, the net emissions come out about the same (unless of course you get your steel from China too).

    On power plants OPOF's rough estimate calcs above showed coal and natural gas powered EVs in roughly the same range as ICEs. More detailed studies are not far different... 100% coal powered EVs are towards the high end of ICE emissions, but for most of the world EVs get their power from sources that put them on par with the most fuel efficient ICEs and in places with high renewable energy generation there is just no comparison... EV emissions can be as much as two orders of magnitude less than ICEs.

    However, the biggest reason that these comparisons are bunk is that they ignore the function of the EV battery. The more EVs are sold the more large rechargeable batteries there are connected to the electricity grid... and the more short term fluctuations in power (such as might be seen by wind and solar power) cease to matter. In short, EVs make wind and solar power more economically viable. Thus pushing the power industry towards cleaner power sources. An effect which completely dwarfs their manufacturing and operational emissions... even if those weren't already on par or better than ICE emissions.

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  6. CBDunkerson: How about some references and data? Sorry, but claims that EVs running on electicity generated predominantly from coal are comparable to ICE vehicles sounds like spin from a vested interest.

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  7. Where I live, almost all of our electricity comes from coal powered generators. In this case a hybrid vehicle makes more sense than an electric. 

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  8. One Planet is correct that the generation mix where you live is important. While his example of Alberta generates more than 50% from Coal, Ontario generates most of its electricity from nuclear (~60%) and hydro-elecrtic (~24%), with a few natural gas peaking plants (~10%), which are intended to reduce occasional peak-use coal-generated imports from the US midwest. Solar and wind combined are bit players (~6%).

    Digby's CO2 emissions of manufacturing (and recycling) are a red herring already dealt with.

    Ogemaniac's example of two-car families is a large part of the problem in the first place, while the occasional need for greater range and/or cargo capacity is what car sharing and rental companies are designed to solve.

    The fact is we're stuck with the infrastructure we have until we build it's replacement. If you are waiting for perfect you will be waiting forever.

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  9. As we transition to renewa le energy in our grids, less and less of the "EMBODIED ENERGY" "embodied energy" of an electric car is from fossil fuel

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    Moderator Response:

    [JH] The SkS Comments Policy prohibits the use of all caps.

  10. Electric vehicle efficiency ranges from 20 to 25 kWh/100 km?

    I'm driving a Nissan Leaf since february:12,5 kWh/100 km

    In Augustus my solar panels produced enough for 5000 km

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  11. Jim Eager @8

    I have no idea what emissions are involved in the manufacture of any car, let alone an EV.  I was just curious about the piece I read concerning embodied emissions.  You say it's a red herring.  Is that because manufacturer's are able to transition to zero-carbon methods of manufacture?  I can imagine that should be possible to a certain extent.  I'm not sure, however, about mining of materials and transport of parts by sea, for example.  To put it another way, I don't understand what's going on and would appreciate enlightenment!

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  12. ric@10.

    You may have a magic touch with your Leaf, or are just not driving fast and never drive in cold weather.

    According to the latest promotional material from Nissan Canada the maximum performance expected is up to 172 km with the 30 kWh battery = 17.5 kWh/100 km (that would be performance without needing heat or air conditioning with minimal acceleration during the trip and a reasonably low speed).

    However, I have just seen that the latest Tesla website indicates longer ranges for their Tesla S than previous years (the Tesla sites previously showed that 18 kWh/100 km was the best expected performance). It indicates performance as good as 11.0 kWh/100 km for their cars at 70 km/h at 20 C and warmer (not running the heat or air). At 70 km/h but -10 C with heat on the performance drops to 15.5 kWh/ 100 km. At 100 km/k and -10C the performance drops to 20 kWh/100 km. And here in Alberta we can drive 110 km/h (legally 110 and many people choose to drive closer to 120). At 110 km/h and 20 C the Tesla will do 19 kWh/100 km. At 110 km/h and -10 C the Tesla S will do 22 kWh/100km.

    And here is a reality check. In Alberta (and many other places) the winters are often colder than -10 C (In Alberta every winter is almost certain to have several days where the daytime high is colder than -20 C), temperatures that Tesla has not included on their website feature.

    So you could be getting 12.5 kWh/100 km as long as you never drive faster than 80 km/h (never go on a highway trip or use a freeway), and never use the heater, and your Nissan Leaf is as aerodynamic and technically efficient as a Tesla S.

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  13. I sorta trust this guy, who says if your grid power is coal-heavy (China, India, Australia, S Africa) your electric car is getting 25-30 mpg (us) if it were a gasoline engine, and in UK, Germany, Japan, and Italy more like 45-50 mpg (us).  In low carbon economies, like France, Brazil, Switzerland, and Norway, more like 100 mpg (us).  In Colorado, 30mpg, while in Caifornia, 70 mpg.  This seems similar to calcs by OnePlanet@1.  So, the advantage as economies (hopefully) decarbonize is apparent, along with the electric grid storage advantage noted by Dunkerson@5.

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  14. ubrew12 @13, he certainly has an interesting map:

    However, the Australian government's Green Vehicle Guide gives different figures, with following Fuel life cycle values for all electrical vehicles:

    BMWi3 121g/km

    Mitsubishi iMiEV 127 g/km

    Renault Kango ZE 146 g/km

    Nissan Leaf 163 g/km

    Tesla Model S 174-186 g/km

    Holden (GM) Volt 127 g/km

    All of these are substantially lower than the 222 g/gm shown in his map.  That may be because his data is at least three years old (based on comments), and the mix of grid electricity sources has changed, or because the Australian government allows for domestic solar in the mix (which he excludes), or because his estimates of charge used per kilometer driven are too high.

    For what it is worth, the figure above are comparable to the most efficient petrol driven vehicles, and inferior to hybrids.

    That being said, in Queensland it is possible to purchase 100% renewable energy from the grid at a surcharge.  Using that option, your electrical vehicle will return Fuel life cycle values far better than even hybrids, and still cost less for a charge than it does to fill up a tank.  Unfortunately they will not return 0 g/km as the "renewable" energy includes energy from waste disposal incinerators.  Given that, the best option for urban driving in Australia is to purchase a fully electric vehicle and tailor your electricity plan.  That not only gives you the lowest fuel life cycle efficiency, but creates a positive economic incentive to increase renewable sources.  At the same time, it helps bring down the cost of electrical vehicles.

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  15. We use our VW e-up! for all journeys up to about 65 miles round trip (giving us a safe margin and no range problems in 2 years and 9,000 miles).

    An advantage of the VW EV models is that they can charge from an ordinary domestic power point - drawing about 2.2 KW (adding about 8 miles range per hour of charging). During daylight hours in the (English) summer our solar panels often produce more than this, and since it is easy to choose when we charge we are literally running on sunshine for much of the time.

    The good feeling this gives us is worth a great deal, adding to the sheer delight of driving this lovely little vehicle. (Motoring Which's 1916 Best Buy City Car - although we are semi-rural).

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  16. I think a light has gone on!  I'm not interested in comparing EVs versus petrol- and diesel-fuelled vehicles, I'm interested in knowing if EVs can still be manufactured in a zero-carbon economy.  Does anybody have a definitive answer?

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  17. Digby, you might as well ask if anything can still be manufactured in a zero-carbon economy.

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  18. Jim and Digbyu,

    Mark Jacobson and the Solutions Project have documented how 100% of all energy: electrical, transportation and industrial, can be generated using renewable energy (primarily wind, solar and hydro).  All currently manufactured products can be manufactured in a zero-carbon economy.

    Iceland currently generates an excess of electricity using geothermal.  They use the excess electricity to manufacture aluminum, which they export.  They could manufacture whatever they wanted to, but they make the most money from aluminum.  As renewable energy gains more market penetration the carbon content of products will decrease.

    Renewable energy only became cost effective in the last five years or so.  You cannot expect 100% conversion instantly, it takes time to build out a new energy system.   Now that renewables are the cheapest source of new energy, more and more will be built.  If a carbon fee is implemented the switch over will be faster.  Jacobson has demonstrated that the entire economy can be run off renewables.  The question is: can the political will be found to implement this solution before critical damage has been done to the Earth system?

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  19. Michael, I don't disagree, I was trying to get Digby to recognise that there is nothing special about the manufacture of EVs. Steel is steel, glass is glass, rubber is rubber, plastic is plastic, whether it is part of an ICE or EV vehicle. The only difference is the lithium mined and refined for their batteries, but that is offset by their not needing a lifetime supply of fuel, engine lubricating oil, transmission fluid and antifreeze.

    That said, manufacturing some products will never be completely carbon free. Carbon is necessary for the smelting of iron ore and production of steel, even in an electric furnace. CO2 is a byproduct of making Portland cement, even in plants using electric kilns. Plastics will continue to require petroleum and natural gas feed stocks. But it's not the manufacture of those materials that generates the lion's share of CO2 emissions, it's transportation, electrical generation and space heating that are, and EVs directly address one of those.

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  20. One planet @12

    No magic touch

    I live in Belgium, temperatures are not extreme here (and I started driving in March). On a highway I rarely drive faster than 100 km/h, but I frequently need the airo.

     Don't forget, you can in reality not use all the 30 kWh of a 30 kWh battery (don't ask me why)

    In reality: maximum performance 200 km with 26 kWh battery = 13 kWh/100 km


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  21. I'm with Jim. Making steel without coke is difficult and expensive. However, if that was the only thing we used coal for, we wouldnt have a problem. You would make an enormous difference to GHG emissions if you could just dump coal for electricity generation. This has to be the number 1 priority.

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  22. rik@20

    It makes sense that the range would be for less than the full battery capacity. My hybrid never allows the battery to go below a certain minimum charge level. The same is probably true for an EV battery.

    Your location and the temperatures you have been driving in would result in the best EV efficiency. The Tesla range tool on the website I linked to in my previous post shows that the Tesla S range increases slightly in weather warmer than 10 C, even with the AC on.

    However, you are likely to see a signicant reduction of EV performance when it gets cold enough to need the heater. In Alberta an EV would be in colder weather at least half of the year.

    Another advantage of a hybrid that I did not mention is that as the battery capacity degrades an EV experiences all the lost capacity as range reduction. A hybrid would only experience limits to the maximum that can be generated and stored on a long downhill. However, unlike an EV the hybrid cannot be left plugged in and it is required to be run at least every 6 months to maintain minimum battery power. A hybrid left too long can have a major repair bill to get it operating again (you can't just boost power back into the lithium ion battery and have everything be fine).

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  23. Jim, Michael and Scaddenp

    Listen guys, don't confuse me!  I asked a hypothetical question.  Is it possible in a hypothetical zero-carbon economy to manufacture such an animal as an EV?  I'm curious because I hear that humanity should have transitioned to a zero-carbon economy by the year 2050 if we're to avoid a climate catastrophe.

    All right, so does "zero-carbon" mean what it says?  From Michael the answer seems to be "yes" ("All currently manufactured products can be manufactured in a zero-carbon economy").  From Jim and scaddenp the answer seems to be "no" ("manufacturing some products will never be completely carbon-free").  I assume that the necessary mining and transport of parts and materials is included in "manufacturing".

    I'm sorry if I seem obtuse.  Also, my curiosity is moot, because we'll never get the world economy anywhere near carbon-free before disaster strikes, which in turn will render notions of manufacturing EVs moot as well.  Um, I probably have to apologize for my pessimism as well!

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  24. I think "zero-carbon" is likely to mean "zero net carbon". You have various options for carbon sequestration from direct capture at steel smelter (highly unlikely) to reafforestation, biochar etc. Theoretically you can do steel without coke - just expensive - see here for example. It is also not clear to me whether plastics necessarily releases CO2. You need hydrocarbons for sure, but do you need to combine with O2 in the plastic process? Cement releases CO2 in manufacture, but it also absorbs CO2 and there is work on CO2-neutral cement (over the long term). Mining and transport can electrified theoretically as well, though an electric heavy digger is long way off I think. You could however also use biodeisel for applications where electric motors really dont cut it. I think it is important to realise that you dont have to be zero-carbon to starve off "disaster" (a highly subjective term)- killing coal may be enough by itself, and if not electrification of private transport as well is almost certainly enough. Anything that reduces rate of emission growth will also reduce the rate of heating and it is rate that is crucial in terms in impacts.

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  25. Scaddenp, the SciAm article you linked to addresses iron smelting electically instead of in a blast furnace, but turning iron into steel requires carbon, period. Adding carbon is what makes it steel. That said, there may be more efficient ways to add that carbon without by-emissions.

    While much work is being done on developing economic CO2-neutral cement, I fear full adoption will be a long way off in developing countries.

    As for electric heavy diggers, electically powered building-size draglines have been employed in large strip mines for many decades now.

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  26. Jim Eager and others,

    "Zero-Carbon" does not mean no carbon in any from. It is just a marketing buzz term since that is what maketing today is all about, brevity in the hope of communicating broader meaning.

    The term means no net CO2 or other GHG emissions produced and accumulating in the recycling environment of the planet, particularly increases in the air and oceans.

    So adding the small amount of carbon into iron to make steel is totally OK in a "Zero-Carbon" economy, as is the making of plastics. Note that ensuring that human activity is sustainable with no accumulating damage done by the production, use or disposal of anything is a separate equally important aspect of the required advancement of human activity. It is actually the higher level requirement that CO2 emissions and deforestation and so many other activities would be a sub-set of.

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  27. Jim, well yes, but I am rather assuming that "Zero-carbon" is shorthand for zero CO2. Sure steel is iron-carbon alloy, but the CO2 emissions from steel making are from burning carbon as fuel and using CO as the reducing agent. The article outlined an alternative technology for that. Nothing to stop you using biochar for carbon addition.

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  28. Jim Eager @25, OPOF and scaddenp have largely covered this.  In short, using electrical arc furnaces with the addition of carbon as a doping agent greatly reduces the CO2 emissions from steel production.  There is still some combustion of carbon, and some of the carbon included in the steel will combust during cutting, welding and grinding operations, not to mention while rusting.  However, the use of charcoal (or charcoal by a fancy name, ie, "bio-char") instead of coking coal to provide the carbon makes steel manufacture a net, short to medium term sink of carbon.  The majority of coal used in blast furnaces is combusted for heat, so use of charcoal is viable in terms of production quantities, but apparently, charcoal does not allow as readilly as coke, so there are some technical issues to work out to avoid loss of efficiency and/or steel quality.

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  29. So what is the consensus?  That in an "effectively" zero-carbon economy it is definitely possible (in theory, if not in practice) to manufacture all the products we manufacture today?  Does this include sea transport?

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  30. Digby Scorgie @29, sea and air transport are tricky.  They can definitely be replaced by carbon free alternatives (sail, and solar powered blimps respectively), but at much slower transport speeds and hence higher transport costs.  They can also be made carbon free by the use of biofuels, but there is reasonable doubt that enough biofuels can be produced to maintain current transport levels while also avoiding famine.

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  31. Digby,

    Mark Jacobson and his group think all energy to support a modern economy can be generated using renewable fuels. They have won several major awards for their work including the Cozzarelli prize for best paper in 2015 from the Proceedings of the National Academy of Sciences.  They could not have received that award if the editors did not think their plan was well founded.  Their publications have hundreds of citations.   Most of the people who cite them agree.  Anyone who wants to claim that great sacrifices must be made to reduce carbon pollution has to say what they think is incorrect with Jacobsons' plan.

    Some of their examples seem difficult to me (I am not an expert).  However, there are alternatitives that could work instead.  For example, Jacobson suggests that hydrogen powered airplanes could be developed.  An alternative would be biofuels (which have their own problems as Tom suggested) or the US Navy has developed techniques to make jet fuel from sea water and electricity.  The primary issue with making fuel from CO2 is cost.  How much do we really need to fly, what are we willing to pay? Jacobson does not like these options because he feels that any combustion of organic materials makes too much pollution.  Society may decide that the pollution is worth the lower cost.

    If people decide they want to stop carbon pollution it is possible to transition to a renewable economy.  If most people install solar panels their electricity will be cheaper than it currently is.  Some portions of the economy will be better, for example air pollution and ensuing health issues (over 13,000 people are killed each year by coal pollution in the USA alone)  will decrease a great deal, others like air travel might be more expensive.  Currently in China air pollution reduces everyones lifespan by at least 5.5 years.  What are they willing to spend to live 6 years longer?  They currently install more renewable energy than any other country.  As renewables continue to decrease in cost more will be installed.  Would you pay triple for air travel if it saved all the buildings and infrastructure between 6 and 30 feet above sea level? I would.

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  32. michael sweet @31

    I'd like to think one can still manufacture all of today's products, including EVs, in a zero-carbon economy.  I've also read about Jacobson's work, but let me put it this way: I'm sceptical!  And then you get comments such as Jim Eager's that some products can never be carbon-free.  What do you say to that, Michael?

    I've read about such things as electric-arc furnaces, carbon-absorbing cement, and alternatives to jet fuel.  I looked at a shipping website and discovered that the shipping people are also concerned about their fossil-fuel habit and would like to kick it, but find it difficult.  I know fossil fuel is needed for plastics, and I assume this doesn't mean having to burn the stuff.

    Regarding jet fuel, for example, I read about a US experiment where ammonia was used to power both a helicopter and an aircraft.  Ammonia can be manufactured using renewable sources of electricity, which makes it carbon-free.  Then I was told (at SkS) that more-advanced synthetic fuels are being investigated, presumably different from biofuels.  So there are hints of a solution but there remain intractable difficulties with transport.  By contrast, generating electricity using renewable sources is simple.

    So, to sum up, I'm sceptical that we can really decarbonize the global economy.  I'll believe it when I see it.  And finally, I think it's all theoretical anyway.  Climate change will clobber us first.

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  33. Digby,

    I think you are being needlessly negative.  It will be more difficult to make some products fossil fuel carbon free than others.  So what if steel requires carbon?  As Scaddenp and Tom Curtis point out above, biochar will make steel as good as fossil fuels.  This would remove carbon from the atmosphere when making steel using electric arc furnaces using renewable energy.  This techology has already been developed.

    Once you have jet fuel from seawater , you can make any other hydrocarbon you want.  Ocean freighters can burn jet fuel in their current engines without any modifications (Jacobson prefers hydrogen).  Cost is estimated at US$3-6 per gallon (US$.75-1.5 per liter), less than gasoline in many European countries today.  Plastics can also be made through this process using CO2 from the atmosphere (the Navy apparently found it was cheaper to get the CO2 from the ocean than from the air).  I have seen articles that use plant based feedstock to manufacture plastic also.

    There is no question that it will be a big job to convert our entire economy to a new source of energy.  On the other hand, there is no doubt that fossil fuels will run out in 200 or 300 years even if we burn all the carbon in the ground.  Do you expect our decendants to live in caves and revert to stone tools after all the carbon is gone??  I do not know anyone who has suggested that will happen  We all expect them to figure out a new source of energy.  We have that source availabe to us right now, it is wind and solar.

    Currently business uses fossil fuels because they are the cheapest.  Wind and solar have very recently become the cheapest source of electricity.  As they are built out they will be able to replace fossil fuels for industrial heat and other uses. The best path forward is to convert the easiest energy first to renewables: electricity.  Then you start to work on the harder processes.

    Jacobson has demonstrated that there are multiple ways to get to fossil fuel free economies.  There are multiple technologies for all of the objections that you have raised.  I like the idea of jet fuel from sea water.  Jacobson likes hydrogen power (with the hydrogen generated by electrolysis from renewable power).  In 30 years we will see which tenchnologies win out.  I doubt anyone today can predict exactly which technologies will be most successful.  Just 10 years ago no-one thought that wind and solar would be as cheap as they are today.  

    Once renewable energy dominates the electricity market it will start to penetrate other markets.  An example of this is the manufacture of aluminum in Iceland using renewable electricity from geothermal energy.  Iceland is cutting into the market for Alminum made with coal electricity from Australia.  Don't expect industrial manufacture of hydrogen (or jet fuel) until the electricity market has gone mostly renewable.

    It is difficult to keep a positive face on in response to political stupidity, especially in the USA.  It seems to me that we have no other choice, if we lose hope why should we build out renewables?  The sooner we go full bore on renewables the less damage we will have to deal with.  If we built wind generators like tanks were built during WWII we would emit much less CO2 in a decade.

    The great positive is that renewable energy is now cheaper than fossil fuels!!  Ten years ago it looked like the only way to get widespread acceptance of renewables was if the government heavily taxed fossil fuels.  Those taxes have always been a political long shot.  Now renewables compete without subsidy in many locations.  And the price of renewables continues to go down!  Walmart, Costco and Ikea are putting solar panels on top of their stores!  Other major companies are loooking at solar because they save so much money.  

    As renewables gain market share it will become easier to raise taxes (or lower subsidies) on fossil fuels.  Already the coal companies in the USA are going bankrupt!!  Coal power plants are shutting down.  There is discussion of making coal companies pay fair fees to mine on public land.  As more wind and solar are built out it will become uneconomic to frak for gas.  Unfortunately, nuclear was the most expensive power and is being eliminated along with coal.  The response must be to build out renewable energy faster.

    It is difficult to respond to a post like yours that lists multiple questions about many technologies.  If you separate your questions into smaller chunks it is much easier to have a discussion.

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  34. michael sweet @33

    Pardon my pessimism.  All right, I'll concede that all the solutions for decarbonizing the global economy are known.  They just need to be implemented on a world-wide scale.  Does that sound better?!

    We are therefore in a race.  On the one hand we have to transition to a zero-carbon economy.  On the other hand, the climate is changing for the worse at an ever-increasing rate.  There are two possible outcomes.  In the first scenario we transition to a zero-carbon economy in time to avoid the worst climatic effects.  In the second scenario the climatic changes are too fast and disrupt our economic transition, which leads to a collapse of our global civilization; a few local civilizations are left struggling on here and there.

    Which scenario is the most likely?  The problem with the first scenario is that an enormous amount of social inertia has to be overcome even before we can implement the necessary changes.  This is the main reason for my scepticism.  But like any science-minded person I will change my mind if the situation changes.

    As a postscript I'd like to add that, while I'm pessimistic, I still think it is essential that we fight like hell to change our attitude to the economy.  It simply must be decarbonized.  But I'm a tired old man.  Please forgive me if I just sit back and watch what happens.

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