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The Future for Gas (And Hydrogen) Guzzlers

Highlights:

  • Ironically, improvements and cost reductions in electric motors and batteries will help the internal combustion engine (ICE) through hybridization.
  • These cost reductions combined with substantial engine downsizing can make hybrid drivetrains cheaper than conventional ICE drivetrains.
  • In addition, future hybrids will avoid the large trade-off between power and efficiency of pure ICE cars, leading to broad consumer acceptance. 
  • Fuel cell vehicles will follow the same downsizing philosophy to keep the high cost of the fuel cell stack to a minimum.

Introduction

In the previous article, I outlined the main arguments why the internal combustion engine (ICE) will remain highly competitive with battery electric drive even as battery prices continue to decrease. This article will go into more detail about what these highly competitive ICE drivetrains might look like.

Even though the future is less certain for fuel cell vehicles, this technology will also be included in the discussion.

Future ICE drivetrains

Fact: The internal combustion engine (and any other heat engine) functions best under constant load. If the engine can constantly work near its optimal operating point, efficiency and longevity increase dramatically, complexity and costs reduce, and emissions control becomes much easier and cheaper.

Electric drive, on the other hand, is great for variable loads. Efficiency remains high, maximum torque is available even at low power output and mechanical energy can be efficiently recovered to electrical energy under braking.

Hybrid drivetrains aim to synergistically combine the internal combustion engine and the electric motor to fully capitalize on these fundamental characteristics. Even though hybrid drive has been around for about two decades, great room for further improvement exists. Continued cost reductions in electric drivetrains and battery technology combined with further development of ICEs especially designed for hybrid drive can lead to higher efficiency, lower costs and a better driving experience.

Power requirements during driving

To better understand the potential of hybrid drive, it is important to realize just how little power it takes to maintain constant speed (the role of the ICE) and how much power it takes to accelerate (the role of the electric motor). To illustrate this, three simple graphs are presented below.

The first graph shows the horsepower (hp) required to maintain a given constant speed for a car weighing 3050 lbs with a frontal area of 22 ft2 (typical Toyota Prius numbers) for different drag coefficients (source). Even at a speed of 60 mph, only 11-15 hp is required.

The thing that really takes many horses is acceleration. As shown in the graph below, accelerating even at a fairly modest rate equivalent to a 10 s 0-60 mph time takes almost an order of magnitude more power than maintaining speed at 60 mph.

Hills also require quite a lot of power depending on the gradient.

For these simple reasons, the hybrid of the future will have an engine that has substantially less power than the electric motor. The engine will be responsible for most constant speed driving, while the electric motor will provide the short bursts of larger power required by acceleration and steep hills.

The small-engine hybrid

Based on the above graphs, no more than 50 hp will be required for an ICE in a standard car. This ICE can then be complemented by a 100 hp (or stronger) electric motor with about 5 kWh of battery capacity to provide enough flexibility for longer periods of higher power (e.g. getting up a mountain pass).

Naturally, the worst-case scenario for such a car is running out of battery, leaving you with only 50 horsepower (which is still much better than running out of juice in a BEV). Under regular driving conditions, however, it will be near-impossible to exceed 50 hp for a sufficiently long time to drain 5 kWh of battery capacity without breaking several traffic laws. The battery can be recharged through the engine whenever fewer than 50 hp is required to move the car, through regenerative braking, or through a waste-heat recovery system.

The parallel hybrid configuration will be preferred to avoid the efficiency losses related to using an ICE just to drive a generator (series hybrid). In fact, a generator can be completely avoided since the motor can double as a generator in the parallel configuration. Furthermore, a smaller motor can be used since the power of the ICE goes directly to the driveshaft. With the electric motor having at least twice the power of the ICE, it may be most cost effective to let the electric motor drive the rear wheels and the ICE the front wheels, thereby allowing a downsized ICE transmission system. Given that the ICE will only need to drive the car at cruising speeds, the transmission can be quite simple and cheap.

In this system, the engine does not need to operate under rapidly varying loads. Current hybrids already employ an Atkinson cycle engine which boosts efficiency at the expense of performance at lower loads (where the electric motor does all the work). New HCCI engines could potentially drive engine thermal efficiency to the milestone of 50%, relying on hybridization to avoid ignition control issues under variable load. Diesel could even make a comeback thanks to easier emissions control from a largely constant power output and a larger battery pack allowing all electric drive in population centers.

How low could the cost go?

This powertrain performs well in a cost comparison with pure ICE and BEV alternatives. The graph below shows a breakdown of a future 150 hp car in three configurations. Cost assumptions are $50/kW for the ICE and transmission, $25/kW for the electric motor components (source), $100/kWh for the BEV battery pack and $200/kWh for the hybrid battery pack. A simple 2-clutch system to connect the ICE to the motor for charging the battery is assumed to cost an additional $500.

Drivetrain cost compare

As seen above, the hybrid powertrain performs very well in this cost comparison. Maintenance costs of this future hybrid configuration will also be low thanks the the small ICE operating mostly at constant loads. Today’s leading hybrids are already showcasing this potential. For example, 5 years of maintenance of the Prius costs only $450 more than for the Leaf (while insurance costs are $330 less).

It will be quite a few years before such hybrids start to emerge though. Currently, an electric motor and power electronics cost almost as much as a gasoline engine and transmission, and batteries are still expensive (and unsubsidized for hybrids). Hybrids therefore typically have a small battery pack (~1 kWh) that limits the power and utility of the electric motor. The current cost comparison is given below to show that the proposed hybrid system would be significantly more expensive than a standard ICE.

Drivetrain cost compare - current

Another important development that will enhance the hybrid configuration described above is waste-heat recovery systems. Technologies such as thermoelectric generators, electrical turbocompouding and organic Rankine cycles can convert a small percentage of the waste heat from an ICE to electricity to continuously charge the battery whenever the ICE is operational. This can allow the hybrid to keep the battery pack charged without requiring extra work from the engine.

Good technological development in this field can eliminate the need for any physical connection between the engine and the electric motor, thus offsetting some of the cost of these energy recovery systems. Additional engine downsizing allowed by the efficiency gains offered by these systems will further decrease costs.

Additional benefits

The future hybrid configuration with a greatly downsized ICE will bring at least two significant side-benefits.

Firstly, the hybrid configuration with a large electric motor will be more fun to drive than a pure ICE car. Currently, the hybrid image is still linked to the old Toyota Prius, which was very sluggish to drive. According to the vast majority of professional reviews, this stigma is already being altered by the new Prius and the Hyundai Ioniq. Future models will certainly continue this positive trend. As a result, people will start to buy efficient cars, not as a grudging compromise to help the environment, but simply because they are both cheaper and better to drive. Hybridization is already being used to increase performance in sports cars, the pinnacle of which is Mercedes’ 50% efficient F1 engine (see the YouTube video below).

Secondly, the moderately sized battery pack (~5 kWh) in the future hybrid configuration described above can also be charged from a regular plug overnight. Even though, on average, fuel costs for gasoline and electricity will not differ much for such an efficient hybrid vehicle, adding a plug provides fuel flexibility in the case of high oil prices. Even just a moderate number of such flex-fuel vehicles can provide enough demand elasticity to prevent fuel price spikes. For example, if oil prices start to rise outside of the normal range, everyone with these vehicles can instantly start displacing some of their gasoline consumption with electricity, thus reducing demand for oil and lowering the price.

Future fuel cell drivetrains

The fuel cell vehicle of the future will operate on much the same principles as the ICE hybrid described above. Given that the fuel cell is the most expensive part of the configuration, it will be kept to an absolute minimum size and will be mostly responsible for constant speed driving and gradual battery recharging. Acceleration and hills will be handled by conventional battery electric drive.

Future fuel cell costs are highly uncertain, but $50/kW appears to be possible. The hydrogen storage tank also represents a non-negligible cost of about $1500. To illustrate overall cost implications, the cost of a fuel cell drivetrain is added to the above graph.

Drivetrain cost compare - with FCV

It is shown that the FCV drivetrain is substantially more expensive than the ICE alternatives, but still cheaper than the BEV.

Where will the fuel come from?

Even though we still have lots of cheap oil (below), we will eventually have to move to more sustainable sources. CO2 emissions from the combustion of oil-derived fuels will also become a more important economic consideration over coming decades. The next article will therefore take a look at different ways of producing sustainable fuels for the long-term future.

Schalk Cloete's picture

Thank Schalk for the Post!

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Discussions

Helmut Frik's picture
Helmut Frik on Sep 18, 2017 3:34 pm GMT

A system which would fit for such puropses would be this: https://en.wikipedia.org/wiki/Free-piston_linear_generator or more in detail this: https://de.wikipedia.org/wiki/Freikolben-Lineargenerator as it is currently under development at the university of Stuttgart / DLR. Not reaching higher efficiency, but saving many moving parts of the engine and saving a lot of weight.

Bob Meinetz's picture
Bob Meinetz on Sep 18, 2017 4:34 pm GMT

Schalk, what the source of your graphs/data?

Roger Arnold's picture
Roger Arnold on Sep 18, 2017 7:17 pm GMT

Schalk,

Nice article — or series of articles. We’re on the same page regarding what type of design that makes technical and economic sense, at least for the type of general purpose “family car” that we’re all accustomed to driving. I particularly agree with a point you made in the prior article: that the longer the range and the larger the vehicle, the less sense pure BEVs make compared to various hybrid alternatives. However, I’d still like to say a few words in defense of BEVs.

There are different ways to classify hybrids, but one I find helpful is based on the “authority” of the electrical side. “Full authority” HEVs have motors and power controllers sized to deliver adequate performance over a full range of normal driving conditions. They’re essentially BEVs equipped with range extender engines. They can be — and usually are — plug-in vehicles, and local driving is typically done in pure electric mode. They can potentially have individual wheel motors, and can dispense with drive shaft, gears, clutches, and differentials.

“Limited authority” HEVs, by contrast, have motors and power controllers that are undersized for full range of normal driving conditions. They can operate in electric mode only at low speeds and accelerations. At higher speeds, they require the torque and power of a relatively conventional automotive ICE operating in parallel to deliver adequate performance. All models of the Prius until recently have been in this category. (I’m not sure about more recent models with more powerful Li-ion battery packs and plug-in capability.)

The point of this distinction is that full authority HEVs owe their feasibility to BEV developers and Tesla. It’s where the automotive industry is now headed, but without the production learning curve on batteries and high performance motor-generators and silicon carbide power controllers pioneered by BEV makers, full authority HEVs would not be economically feasible.

Another point for BEVs is that, if one delves deeper into future transportation scenarios and the impact of autonomous vehicles, the role of the high range general purpose family vehicle will be sharply reduced. I think I’ll leave that to a separate comment, however. This one’s already long.

Bob Meinetz's picture
Bob Meinetz on Sep 19, 2017 11:55 am GMT

Schalk, what’s the source for your data and graphs?

Engineer- Poet's picture
Engineer- Poet on Sep 19, 2017 2:56 pm GMT

Even though, on average, fuel costs for gasoline and electricity will not differ much for such an efficient hybrid vehicle, adding a plug provides fuel flexibility in the case of high oil prices. Even just a moderate number of such flex-fuel vehicles can provide enough demand elasticity to prevent fuel price spikes. For example, if oil prices start to rise outside of the normal range, everyone with these vehicles can instantly start displacing some of their gasoline consumption with electricity, thus reducing demand for oil and lowering the price.

This is an unlikely scenario.  Filling up with liquid fuel all the time is inconvenient, whereas charging can be done at any stop where power is available (commonly at home and with increasing likelihood over time in other places).  In addition to the “long tailpipe” moving the energy-related emissions away from roads and cities, the reduced frequency of fuel stops is likely to be a selling point for these vehicles (I’ve gone 3 months since my last fillup and still have half a tank left).

This means that the petroleum demand isn’t going to be more flexible so much as it’s just going to go down and stay down.  Electric demand will go up and stay up.  What this means for the world oil market is probably a shift of demand to “developing countries”, which will be the ones taking the economic hit in the event of shortages.  This hit will largely bypass countries which have electrified their transportation systems.

Rick Engebretson's picture
Rick Engebretson on Sep 19, 2017 7:09 pm GMT

I agree entirely with your hybrid vehicle concepts. As you certainly know, many more variables might be considered, but can’t to preserve the statement.

Personally, many really like close urban work and living environments, so I think simple transportation needs can and should be far smaller for them. Even not so new structural fabrication materials, like wood, lighten the weight and cost of rolling on wheels. 2 horsepower on wheels and paved roads beats 1 horse in the rough 100 years ago.

Also, for all power technology, one size does not fit all. It can get ridiculous out here in the country with tractors, lawn mowers, chain saws, cars and trucks. There really is no standard gas guzzler. But I gotta say the annual mud truck event around here shocks me for emphatic piggery.

On the whole, your approach to safely work from what we have, and develop and prove and market, is tried and true. The “theory” trippers promise us we can fly if we jump, but they always want our money before they push us into the untested void.

Roger Arnold's picture
Roger Arnold on Sep 19, 2017 9:41 pm GMT

Following up on my earlier comment about “family car” model having a diminishing role in future:

In the dawning era of autonomous vehicle capabilities, the personally owned, general purpose “family car” is likely to play a diminishing role. It’s capital inefficient — simply takes up parking space 95% of the time — requires a lot of upkeep, and finding a parking space can be a major hassle. When one can easily call up just the type of vehicle one needs for a particular task, why own?

Vehicle sharing will lead to some reduction in the total number of vehicles, with shared vehicles racking up substantially more miles per year than the current average. But the pattern of morning and evening rush hours will limit the effect. If the fleet of shared vehicles is large enough to handle peak demand, it’s certain that most of the fleet will be idle for much of the day. So there will be plenty of time to navigate to a nearby charging station and plug in. A pure battery range of 100 miles or less will be quite sufficient for the vast majority of shared vehicles.

For longer commutes, I expect to see specialized commuter buses taking over. A big part of the cost of operating a bus is the driver. With drivers out of the picture, a large fleet of small buses becomes quite feasible. Commuter buses will come with secure high bandwidth internet and video conferencing, so passengers can work comfortably while they’re on the road.

Long distance commuter buses will need substantial driving ranges, so they probably won’t be pure BEVs. Hydrogen FC hybrids is a good possibility. If their tanks are filled with pressurized hydrogen chilled to liquid nitrogen temperatures before they leave the barn, they easily could deliver a mass fraction of 12% — double DOE’s target for FCEV feasibility and about the same as water. (H2 chilling isn’t practical for consumer FCEVs, because they may sit with full tanks for indefinite time periods. But it’s a fine option for buses and long haul trucks. It’s even better for short-haul electric airplanes. For the latter, the insulated graphite fiber pressure tanks can serve double duty as structural elements of the plane.)

Schalk Cloete's picture
Schalk Cloete on Sep 20, 2017 6:43 am GMT

Could you be more specific? The article contains hyperlinks to sources for the most important data in the graphs, but I can provide more specific details if required.

Schalk Cloete's picture
Schalk Cloete on Sep 20, 2017 7:05 am GMT

Thanks Roger.

As discussed in the article, I think parallel hybrids (e.g. Prius or Ioniq) will be preferred over series hybrids (e.g. Volt). To me, it does not make much sense to have the electric motor driving the car at cruising speeds where an ICE operates at maximum efficiency. Doing this requires a separate generator, a larger electric motor and involves some conversion losses between the engine and the motor.

I agree that BEV developers helped to accelerate the learning curve for batteries and electric motors, but continued development of hybrid drivetrains would also have gotten there eventually. That being said, BEVs certainly have their place in the future transportation sector, so they will contribute significant demand for motors and batteries to continue the cost reductions.

Will be interesting to hear your thoughts about the impact of autonomous technology on the mix of vehicle types.

Schalk Cloete's picture
Schalk Cloete on Sep 20, 2017 7:43 am GMT

Given that oil is perfect for global trade, this point applies the world in general, not just the US. A few percentage points of the global vehicle fleet with plug-in capability can therefore naturally respond to oil price changes on a global scale, making sure that prices stay in the normal range.

As outlined in my previous article, BEVs don’t have a clear fuel cost advantage over efficient ICEs when oil prices are in the normal range. But they have several important drawbacks that are currently keeping US sales of affordable BEVs at a fraction of a percentage point even though the entire battery pack cost is covered by incentives. I’m therefore skeptical whether the long-term plans of some nations to completely ban ICE cars will actually happen, especially given the potential of hybrid drivetrains outlined in this article. BEVs will certainly grow nicely, but the S-curve will probably flatten out much sooner than proponents expect.

Schalk Cloete's picture
Schalk Cloete on Sep 20, 2017 7:48 am GMT

Thanks, that seems to be an interesting development for range-extender applications. This will be well-suited to a car that is mostly used for daily short trips in the city and only the occasional longer trip. With several attractive car-free mobility options and the potential of high-utilization mobility services, this type of car will probably become less popular over time, but it will have its corner of the market.

Helmut Frik's picture
Helmut Frik on Sep 20, 2017 8:04 am GMT

It will share the fate of all hybrid cars, surely. but it deminishes the disadvantages of hybrid cars with their double drivetrains by eliminating many unneccesary parts of the ICE in the context of a hybrid car. But it could well be that the development of BEV is too fast for this specific hybrid engine to get to the market in time.

Helmut Frik's picture
Helmut Frik on Sep 20, 2017 9:58 am GMT

I see the differences very small, since the parallel hybrid adds significant weight to the system also. Gears and bearings unneccesary in the serial version also are not loss free, reducing the differences to a few percent (low single digit) on highway journey, which is not the optimium use for cars anyway. Most km are traveled in cities and on smaller roads, where the serial hybrid can show it’s advantages, and on smaller journeys where the power comes from the battery, and the additional dead weight of the paralel version hurts.

Engineer- Poet's picture
Engineer- Poet on Sep 20, 2017 2:50 pm GMT

IIUC, both the original and current Volt drivetrains are series-parallel, not unlike the Prius.  Allegedly, the original was closer to series than the current one.

Roger Arnold's picture
Roger Arnold on Sep 20, 2017 7:38 pm GMT

I think I’m with EP on this one, Schalk: I can’t see oil price swings as having any significant short-term influence on the ratio of plug-in vs. fuel energy in the fleet of plug-in hybrids.

If one has a plug-in hybrid, I can’t see any realistic scenario where one would save money by opting for fuel over plug-in energy. The latter will always be cheaper per mile driven. Use of liquid fuel will be largely set by the frequency of trips exceeding the plug-in range.

There may be some elasticity in situations where interrupting a trip for a plug-in refresh is an option. There’s a cost vs. convenience tradeoff there, but if the plug-in range is adequate for most urban trips, I don’t think it will come into play very often.

Long term is a different story. The price of oil, and expectations for its future, will determine how much of a premium consumers are willing to pay to buy a new vehicle with plug-in capability.

Bob Meinetz's picture
Bob Meinetz on Sep 21, 2017 3:50 am GMT

It would be helpful to have some specifics on the data used to create all of the graphs. For example, for “Future Drivetrain Cost Comparison (150 hp),” a link to a 23-page document burdens readers with hunting down the context, methodology, and source.

Nathan Wilson's picture
Nathan Wilson on Sep 21, 2017 5:11 am GMT

Yes, it does make sense that robotic drivers will lead to smaller, more numerous buses, which should improve their service frequency, convenience, and popularity.

As to car sharing taking over, I doubt it. I think (and Elon Musk has said something similar), that robo-drivers will make long commutes more attractive, so we’ll drive more. This reduces the potential cost savings of car sharing. I don’t think it will be popular for people that work (commute) 5 days a week.

Cryo-chilling H2 is a nifty idea, as it gets H2’s energy density up enough to match ammonia’s. However, cryo-chilled H2 still requires high pressure; ammonia can be liquified by chilling to just -33C, so that no pressure is required, which means that it will work in flat wing-tanks like normal jet fuel. And cryo-chilling will use all the energy that was saved by not converting to ammonia. Likely the H2 refueling station would store it at room temperature, otherwise certain accident scenarios involve large H2 releases/explosions, so the refueling stations have the extra burden of chillers.

Engineer- Poet's picture
Engineer- Poet on Sep 21, 2017 7:26 am GMT

ammonia can be liquified by chilling to just -33C, so that no pressure is required, which means that it will work in flat wing-tanks like normal jet fuel.

The problem with that is weight.  Ammonia fuel gives you about 8000 BTU/lb; kerosene packs 20,000.  Your optimal fuel minimizing the detriments of weight and bulk may be liquid methane (I have not done any calculations on this).

yesIhavebeenoverthisbeforewhydoyouask?

Schalk Cloete's picture
Schalk Cloete on Sep 21, 2017 7:32 am GMT

I agree that running on fuel will not have a clear economic benefit over running on electricity. But I don’t think electricity will have a clear economic benefit either. Once EVs also start to pay some form of fuel taxes, it will be roughly equal.

The main reason for preferring fuel with the small-engine hybrid described in this article (during times of normal oil prices) will be the convenience of always having access to full performance. Under normal operation, the car will strive to keep the ~5 kWh battery at a high state of charge, so that it retains maximum flexibility for longer periods of higher power (e.g. long hills or some emergency where one has to drive extremely quickly) or battery-only travel (e.g. a large traffic jam or city regions that prohibit local tailpipe emissions).

PHEV operation will complicate this dynamic. The easiest will probably be for the car to use its navigational computer to drain the battery in EV mode during the final part of the homeward journey. But what if you get home with an empty battery and then realize that another car trip is actually required? The low power of the ~50 hp engine will be quite annoying in this situation. These kinds of occasional inconveniences are enough to make most people use such cars in their regular gasoline mode if there is not a substantial fuel cost difference.

As you mentioned, the convenience aspect of not looking for top-up charging options is also an important factor. During the occasional large oil price spike, more people will be wiling to do this extra effort.

Specialized PHEVs designed for commuting with flexibility for the occasional longer trip will have a substantially larger battery (~20 kWh) and a larger engine (~100 hp). They may also have a more expensive onboard charger and a specialized charger at home (for faster charging speeds). As the aim will be to mostly drive in EV mode, a larger electric motor may also be employed. These differences will make the whole package about $5000 more expensive than the hybrid configuration described in this article. Also, as you mentioned, such a personal commuter vehicle will probably become less popular over coming decades as smarter personal mobility options emerge.

The hybrid drivetrain described in this article will be much more broadly applicable to vehicles of different driving patterns and sizes. I think its low cost, high efficiency, good performance and general applicability can lead to a large gain in popularity over coming decades. Adding a cheap slow onboard charger for fuel flexibility as an option can then bring the added macro side-benefit of controlling oil price spikes.

Schalk Cloete's picture
Schalk Cloete on Sep 21, 2017 8:01 am GMT

Yes, it will be interesting to see the dynamics of personal mobility evolve over coming years. Personally, I think carless personal mobility options (telecommuting, e-bikes and online retailing, combined with car-free neighborhoods and city centers) will have a larger global impact than ridesharing and autonomous taxis/buses. But the kind of mobility services you describe will certainly show impressive growth.

It may be that countries like the US and Australia that were quite literally built for cars may stick to this form of transport for longer. But I think the rest of the world will increasingly capitalize on the great benefits of carless personal mobility options.

One challenge with autonomous taxis/buses with small ranges is that daytime charging may increase peak system load, leading to substantially higher fuel costs. Empty miles required to find parking and charging spaces during the period between rush-hours may also negatively impact economics. I’m also not so sure how productive one can actually be in a bus/taxi navigating city traffic (I’d find it quite hard to concentrate and could even get carsick).

Interesting about hydrogen chilling. What is the primary benefit of this? Cheaper storage tanks or cheaper compression?

Schalk Cloete's picture
Schalk Cloete on Sep 21, 2017 8:08 am GMT

Interesting comment about the 1 hp applied to smoothly rolling wheels. I’m quite excited about the potential of e-bikes to displace car travel in cities. My e-bike has less than 1 hp and can get me to and from the office substantially faster than a 150 hp car navigating rush-hour traffic. Well, actually, my 1 manpower regular bike can also achieve this, but with a bit more sweating…

Helmut Frik's picture
Helmut Frik on Sep 21, 2017 11:22 am GMT

Performance is the easiest task for a electric drive. And there is still significant room for improvements.
Get the data of the new Siemens aviation motor in the head and think what it means:
Delivering 260kW continuous power at 2500RPM. With a weight of just 50kg. A equivalent Diesel has a weight of about 1t without gearbox, given the ability of the electrig engine to deliver torque at all speeds and being able to deliver more power for short times, and usually also more power with more RPM. (I think I did read about the first being correct for starting the plane, and for the second I see no physical limit which hinders that it also applies for this special motor.
(http://www.ingenieur.de/Themen/Flugzeug/Siemens-entwickelt-ultraleichten...)
Since electrical motors are rotational symetrc, they can usually operate with high RPM, even if not written in the manual.
Given someone scales this down to the size needed for a usual car, the engine of the car can be carried in a bigger handbag.
Same engine as generator at the ICE, and replacing the mechanical drivetrain with a electric one will save weight in a significant amount. (the new motor has 5kW/kg, todays BEV-motors 2kW/kg continuous power)
And practical experience with the e-force truck: http://eforce.ch/eforce/leistungsdaten/ have shown that this truck beats any diesel truck – with significant more horsepowers nominally by perormance, e.g. driving uphill with full load.

Schalk Cloete's picture
Schalk Cloete on Sep 21, 2017 8:04 pm GMT

For these graphs, I used the data in table A2 (page 10) in the reference. BEV drivetrain: synchronous motor, power electronics and step-down converter.
ICE drivetrain: gasoline engine, stop-go system and exhaust treatment.
Hybrid drivetrain: all of the above except the stop-go system.

I then calculated the totals for a 150 hp BEV, a 150 hp ICE and a hybrid composed of a 50 hp engine and 100 hp motor. I used a conversion rate of 1.2 Dollars per Euro.

These calculations worked out very close to $25/kW (with charger) for the BEV and $50/kW for the ICE as specified in the article using the Potential (2030) values in table A2 of the reference.

Engineer- Poet's picture
Engineer- Poet on Sep 22, 2017 12:36 am GMT

Interesting about hydrogen chilling. What is the primary benefit of this? Cheaper storage tanks or cheaper compression?

Higher storage density.

Note that ammonia is 17.6% hydrogen by mass.  H2 is just plain a problematic molecule to store.  Chemical reactant, yes.  Pipeline fuel, depends on the specifics.  Vehicle fuel?  It seems to have been selected specifically to put off any real competition to petroleum for as long as possible.

Bob Meinetz's picture
Bob Meinetz on Sep 22, 2017 3:05 pm GMT

Schalk, “in the reference”. What reference? If a reader might logically assume you’re referencing the link in the preceding paragraph attached to “appears to be possible”, then he/she will be disappointed to find out there is no “table A2” on page 10. And continue his/her fruitless search.

You call yourself a “research scientist”. In my experience, good ones unerringly assume they will be fact-checked – that’s how good science works. They fastidiously reference graphs, and footnote/endnote data. They would explain whether the calculations they used to expand data to a 150 hp BEV from another power rating warrants a simple linear projection.

Granted, articles in TEC are not academic papers, and for the sake of discussion we accept some conclusions at face value. But given the presentation above and your relative anonymity, it’s hard to put much stock in any of yours.

Bob Meinetz's picture
Bob Meinetz on Sep 22, 2017 4:52 pm GMT

Schalk, depending on what you had for lunch, riding your e-bike may have less of a carbon footprint than pedaling your regular bike.

Reading Mike Berners-Lee’s book, How Bad Are Bananas? The Carbon Footprint of Everything, one becomes aware of how seemingly-innocuous sources of energy can be painfully carbon-intensive. According to Mike, one bunch of out-of-season asparagus, air-freighted from Peru to the UK, has a carbon footprint of 3.5 kg CO2e. Raising the question: which would be more carbon intensive, riding a bike powered by Peruvian asparagus or driving a truck?

Schalk Cloete's picture
Schalk Cloete on Sep 22, 2017 7:51 pm GMT

I meant this reference: https://www.researchgate.net/publication/260339436_An_Overview_of_Costs_.... It is linked above the first graph in the “How low could the cost go?” section on the word “source”. Let me know if you need more details.

About the style of writing I employ on TEC, I purposefully refrain from the style of an academic paper simply because that would turn many TEC readers off. This less formal style has worked well over the ~70 articles I have published on TEC thus far. However, if someone occasionally asks for details like you are doing now, I’m happy to elaborate.

My peer-reviewed scientific outputs are listed here if that will help justify my label as a “research scientist”: https://www.researchgate.net/profile/Schalk_Cloete2/publications

Rick Engebretson's picture
Rick Engebretson on Sep 23, 2017 6:54 am GMT

It is obvious if we want a smaller human footprint we can’t build ever more roads. So you have proven better wheels on pavement can reduce your footprint by a factor of 10 or better. Experts from Los Angeles are invited to show us any similar progress.

Please take a look at the computer software distribution openSUSE. I have been in this computer stuff for a long time, and this is truly a great human achievement. Cooperative global innovation success. Always green, their current 42.3 artwork theme of a light-bulb with their incandescent SUSE logo lizard is symbolic. You gotta know some people using this, if you don’t use it yourself already.

We are innovation opportunity wealthy today.

Bob Meinetz's picture
Bob Meinetz on Sep 23, 2017 3:00 pm GMT

Schalk, thanks for references. I’m starting to realize with regards to rigor there may may be a European/U.S. cultural divide. Example:

“For these simple reasons, the hybrid of the future will have an engine that has substantially less power than the electric motor.”

That’s a big claim. Though in European research circles they may be common, overarching conclusions like this give U.S. researchers a case of the hives. Why? They ask more questions than they answer: Are both serial/parallel hybrids considered? Is consumer preference taken into account? What liquid fuels are considered? Etc. etc. etc.,,,

Finding the answers to those questions – how you arrived at your conclusion – is anything but simple: the reader either has to search through all the links above one by one, or pester you to tell him/her which one applies.

I gave up when I found your link published in “ResearchGate.net” and apparently nowhere else. ResearchGate.net appears to be a website where anyone can publish anything they want without editorial or peer review. Have any peers reviewed this article? I couldn’t find any, but I have to admit my patience has finite limits.

ResearchGate.net’s disclaimer:

“Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. Publisher conditions are provided by RoMEO. Differing provisions from the publisher’s actual policy or licence agreement may be applicable.”

In research, accuracy is never guaranteed. That why the best research gives readers the tools to find out how it was arrived at, and come to their own conclusions.

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