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Argonne Assesses a Variety of Total Energy Cycle and Emissions Pathways for Plug-in Hybrids; Focus on Charge Depleting Mode

26 December 2007

Anl1
Total energy values for different pathways and powertrains, with a focus on PHEV Charge Depleting mode. Click to enlarge.

Researchers at the US Department of Energy’s Argonne National Laboratory, which has the lead role in DOE efforts to evaluate plug-in hybrid electric vehicles (PHEVs) and PHEV technology, recently compared US near term (to ~ 2015) alternative pathways for converting energy to light-duty vehicle kilometers of travel (VKT) in plug-in hybrids (PHEVs), hybrids (HEVs), a simulated fuel cell HEV and PHEV, and conventional vehicles (CVs).

The study was focused on identifying the pathway that provided the most vehicle kilometers from each of the five main feedstocks—oil, natural gas, coal, farmed trees and wind/solar renewable energy—assessed. The study, presented in a paper at EVS-23, calculated values for total energy, energy by fuel type, total greenhouse gases (GHGs), volatile organic compounds (VOC), carbon monoxide (CO), nitrogen oxides (NOx), fine particulate (PM2.5) and sulfur oxides (SOx).

Anl2
Greenhouse gas values for different pathways and powertrains, with a focus on PHEV Charge Depleting mode. Click to enlarge.

Since the focus of the study was to determine what could be accomplished by offering a PHEV option as an addition to an HEV, the team highlighted the effects of CD [charge depleting] operation in this study.

This allows us to think in terms of the potential per kilometer effects of choosing batteries for PHEVs, in lieu of continued use of conventional petrol or natural-gas-fueled powertrains, petrol HEVs, E85 FFVs, or future use of E85 FFV HEVs, emerging clean diesel (CIDI) engines or fuel cell (FC) powertrains.

The team assumed a US compact-sized car, and used the GREET 1.7 fuel cycle model and the new GREET 2.7 vehicle cycle model as the foundation for the study. It also isolated the PHEV emissions contribution from varying kWh storage capability of battery packs in HEVs and PHEVs from ~16 to 64 km of charge depleting distance.

Among the findings of the study were:

  • More kilometers of service from coal are obtained by the use of coal-generated power to support PHEV CD mode than by converting coal to synthetic diesel (CTL) for use in diesel engines.

  • More kilometers of service from farmed trees are obtained by the conversion of the biomass to power to support the PHEV CD mode than by converting trees to ethanol for use in HEVs or PHEVs in charge sustaining mode.

  • For wind and solar, PHEV CD mode provides far more kilometers of service than the use of the renewable electricity in electrolysis to create hydrogen.

  • Biofuels do not look significantly better than coal-based options on a total energy basis, but do for greenhouse has emissions. Renewable energy options reduce GHG emissions by a factor of three or more, compared to the fossil-based options.

Thus, regardless of which abundant domestic fuel one would wish to use, use of the fuel to serve a PHEV in CD mode would provide more kilometers of service than competing options evaluated.

While we have here highlighted and isolated the effects of CD operation of a PHEV, we recognize that evaluations of the aggregate annual impacts, including CS [charge sustaining] operation, should be considered. Future research will endeavor to explore CD, CS, and annual average operations separately and jointly, and in more detail than discussed here. Finally, we concede that this study is limited, in terms of HEV and PHEV powertrain types investigated, and in the time interval considered. It also largely ignores the potential implications of regulations or taxes on carbon emissions. Nevertheless, it verifies the promise of PHEVs in the near-term, helping assure that research and development dedicated to the introduction and implementation of this technology is well founded.

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December 26, 2007 in Plug-ins | Permalink | Comments (50) | TrackBack (0)

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Another flawed study. In a virtual world, wind and solar generated electricity produce less ghg . In a virtual world, wind and solar generated electricity can be separated from fossil generated electricity to charge batteries while ignoring that wind and solar are (and most likely always will be) an insignificant source of electricity in the US . In a virtual world, cars with a few hundred pounds of batteries will use less energy. The result is a flawed conclusion:

“Nevertheless, it verifies the promise of PHEVs in the near-term, helping assure that research and development dedicated to the introduction and implementation of this technology is well founded.”

There are some good reasons to research PHEV, AGW is not one of them.

In the real world, wind and solar generated electricity produce less ghg (Wind < Nuclear < Solar << Gas < Coal). In the real world, wind and solar generated electricity are often separated from fossil generated electricity for a number of applications. Bear in mind wind and solar (and nuclear) could be a significant of electricity in the US (as wind is in Denmark and Nuclear is in France). In the real world, cars with regenerative braking use less energy and cars not using 25% efficient ICEs use less energy.

Global warming is one reason to favour PHEVs, except perhaps where the grid supply is predominantly coal generated. Reduction in local pollution and reduced dependence on oil are other reasons. Avoiding fuel tax is a good individual reason for motorists in Europe.

The ideal is power generated by solar light and heat with heat energy stored for use when the Sun's energy is not available. The ideal mode of transportation is long-range, quick-charge light-weight BEVs. All other forms of power generation and propulsion are interim to these two models and are the result of economic and political self interest. We should be making an all out effort to transition to Solar as soon as possible for that is the our energy destiny.

I'm always rather skeptical about anything coming out of Argonne Labs.

In particular, initially what I find a bit bizarre is how it says running a PHEV on coal electricity is worse than driving a conventional car in Greenhouse emissions.

More specifically, I'm rather skeptical about anything based off of Michael Wang's GREET model.

The Argonne folks are far from the first to realize that PHEVs, even powered from today's mostly coal grid, are cleaner GHG-wise than conventional cars.
The reason: the engine efficiencies. A "good " conventional internal combustion engine is maybe 20% efficient at converting fuel to motion (and most of them aren't that good).
An average electric engine, of the type you'd put in a PHEV, is 97% efficient at the same task.
So even using a fuel that's twice as dirty, you use so much less of it that the overall result is a cleaner car.
Again, this is neither new, previously unreported in the scientific press, nor rocket science. Be as skeptical as you want of Argonne, but the horribly inefficient internal combustion engine does indeed make coal PHEV's better than today's cars.
What to do about this fact is up to us.

Give Kit P a break.  It's not nice to make fun of the insane; it's not their fault that their neuroses force their conclusions regardless of facts or reason.

Then again, someone who needs help that badly shouldn't be wasting time here.  Get thee to an asylum, go!

Sadly, these data are completely biased toward BEV, by assuming less efficient method of generating H2, and giving less efficiency for SI-HEV than actually achieved in real life.

Both BEV (battery electricity vehicle) and H2-vehicle will be needed to maximally exploit renewable energy.
BEV will represent small-size and short-range vehicle used for daily commute. BEV's are simple to produce and to maintain, and the small size and short range will keep the overall costs down to minimum.

Larger vehicles will be powered by hydrogen, or synthetic methane or liquid hydrocarbon, since the weight and cost of a large battery pack will be prohibiting.

There is a large seasonal mismatch between the rate of renewable energy production and energy demand. Summer produces a lot of solar energy, while spring and fall produces a lot of wind energy with respect to demand, while winter requires a lot of energy for heating and lighting with very low solar energy production. As such, there will be a need to produce H2 from the surplus solar or wind energy in one season, and to store it for the next season. Battery electricity alone cannot store a massive amount of energy to use in the next season. When we will have a massive amount of stored H2, then H2-vehicle will be practical to take advantage of the stored H2.
The same argument goes for nuclear energy, which is produced at a constant rate, while the demand for energy will be highest in the winter. As such, there will still be a need to store nuclear energy production as H2( hydrogen).

The waste heat of a gas-turbine power plant can be used toward high-temperature electrolysis of water for H2 production, thereby giving the electrical energy efficiency of wind electricity of up to 140%, vs. the efficiency of room-temp electrolysis at 75-85%. When solar energy is used, both heat and electricity can come directly from the sun. When combining this high level and high efficiency of H2 production, in combination with the likes of the Honda FCX Clarity having 3x the efficiency of a comparable gasoline vehicle, you will see that H2-Vehicles can have comparable overall efficiency with BEV's.

Roger

The efficiency of electrolysis at room temperature is certainly not what you claim. High efficiency electrolysis can only obtained at very high temperature where the waste heat of a gas_turbine is of no help.

Honnestly, between a hydrogen econmy where you need to developp an infrastructure of multi trillion $US and that would result in doubling the energy consumption per mile, and a PHEV economy where you can use an existing infrastructure, that give a much better efficiency (at least twice as better), is totally flexfuel, that can use renewable input (wind, solar, biofuel, fossil fuel) and the technology already exist (hybrid car with bigger battery), does the question bteween H2 qnd PHEV really makes sense, isn't the choice already made?

Storage of energy using H2 is one of the most inefficient one, compressed air is better in that regard.

We don't need an H2 economy or civilisation, we need a sustainable energy civilisation or economy.

KitP, you are right that solar and wind power have in practise led to an increased use of coal and are not clean in that sense (in Germany there's growing opposition against wind because of this fact).
But you can couple bioenergy to solar and wind to provide baseload power and create an almost entirely green electricity infrastructure.

Moreover, if you couple CCS to bioenergy (so-called 'bio-energy with carbon storage') and couple this to intermittent wind and solar, you can even obtain a negative emissions electricity system.

Just think of what that means: the more you drive a biomass+solar/wind powered vehicle, the more CO2 you take out of the atmosphere!

This is pretty feasible and highly efficient.

I'm getting increasingly annoyed with Roger Pham.  He uses claims like "140% electric efficiency" without considering that a great deal of energy would have to be supplied as heat from fossil sources.  Maybe he's just ignorant, but he presents himself as knowledgable.

Get a clue, Roger.

It is encouraging that the company, NanoSolar just started shipping their mass-produced thin film solar panels. The company expects to reduce the price of the product to 99 cents per watt after production reaches critical mass. A this price point, the other forms of generation, including coal-fired plants will be too expensive to use and will no longer make economic sense.

Lad

Not so fast, Nanosolar hasn't proven anything at an industrial scale yet. We are not supposed to believe everthing they claim at this point. Iogen also claim that their cellulosic ethanol process works, but so far their pilot line only produces a quarter of their initial target. Also even if nanosolar succeed (which I truly wish) I am not convinced that individual solar electricity production will ever reach more than a few percent of our needs. (Germany has already spend quite some money in solar electricity and only produces 0.3 % of their electricity this way) The problem of intermitency of solar energy as well as poor efficiency conversion are quite a limiting factors. I personaly believe that the bulk of solar electricity will come from giant plans in sunny places like nevada desert using simple thermal conversion that are easily scalable and have 30% conversion efficiency and can handle the problem of intermitency using heat storage in big water tanks rather than semiconductor thin films with poor efficiency and offering limiting durability.

This Argonne study incorrectly uses LCA methods. Comparing different methods of making electricity is a valid use of LCA to provide information for policy makers. Comparing different methods of powering POV is a valid use of LCA to provide information for policy makers to serve the will of the public.

Here is the scam. Valid LCA must consider all the the environmental impacts and all of the public. Renewable energy is not benign. Presently the part of the public that lives in ugly cities want to pave the country side with solar panels and windmills. I little bit is interesting. However, before solar and wind pass 1% of energy generation; the environmental impact will be too much to tolerate.

It is interesting that Argonne included data on insignificant sources of electricity such as wind and solar but took this position:

“A notable decision was to leave nuclear power for PHEVs out of the set of options evaluated, due in part to the anticipation that too many issues need to be resolved to anticipate an expansion of nuclear power to provide services to PHEVs in the 2015 time frame.”

Power up rates at nuke plants are very significant compared wind and solar.

This is a flawed study. For some reason they have ignored the least cost solution that is actually the course being followed by the world. It also results in the least cost and lowest CO2 emissions answer,betering solar-PHEVs. It is nuclear-PHEV.

We can already disscern what the future of Ground Transport and its energy sources will be at least in the USA,but also across the world. We are committed to a mixture of electrical energy generation of about 40% fission nuclear, 13-15% falling water, 40% coal and maybe 1% other renewables (wind, solar thermal, solar PV, geo-thermal, yada, yada, yada.) This is certain from from actual committed and on-order purchases of electrical generation plants, over the next decade and a half, and not some dreamy projection. This is in contrast to today's mix of almost 55-60% coal, 19% nuclear, 16% hydroelectric, a few percent gas and oil and a smidgeon, (well under 1% other "renewables") Nuclear increases, coal drops, and the others become a smaller proportion of the larger electrical supply. So-called renewables grow from next to nothing to a little more of nothing.

The fossil portion of the energy need, for Ground Transport, down from 99.9% today, to about 25-30% of present demand, will still come from liquid hydrocarbons. That conversion is comitted by the investments of automakers world-wide in infrastructure and manufacturing plants on order. These factories will build the combined fossil and electrical vehicles finishing design in their laboratories.

As much as 50% of that reduced hydrocarbon supply might come from "biofuels" but only as long as the subsidies continue, unabated.

As soon as the subsidies dry up, as was the case with Mr. Carter's uneconomic synfuels, the biofuels industry will likely also wither and dry up,as will some other exotic fossil projects.

It is just not cost effective.

Liquid hydrocarbons at the present rate of use, requires that lower quality reserves be mined/pumped ranging from regular oils, heavy oils, to oil sands, to oil shales and even coal-to-liquid, and then the bio-fuels of various kinds. At the margin, biofuels with lots of subsidy, can exist.

However, the liquid hydrocarbon demand will decline to a quarter or so of today's demand, with conversion of Ground Transport to electricity serving as a primary "fuel". It will do so by the late teens or early twenties. Then many marginal high cost liquid hydrocarbon sources will become increasingly uneconomic. To keep many projects alive will require a greater and greater economic drain unless very heavily subsidized by government fiat. The dimensions of the subsidy cannot long endure.

Even if there is a continued concern for CO2; and it is proved to be a valid concern, the absolute reduction in anthropogenic CO2 by conversion to partial electro-motive operation, will likely render the concerns moot.

But the Science of the 21st century, as is acknowledged by the UN's IPCC itself, is increasingly proving that the fears of the relatively primitive Science of the 1970's and 1980's is overrated and unfounded.

If you want to know what the products of tomorrow will look like, it pays to look at what is on order and beimg built in the factories of tommorrow, but which are themselves being ordered and built today.

I believe leaving nuclear out of the mix is intentional. I for one do not agree with government sources that say a plane cannot penitrate the four foot concrete thick nuclear containment structure after seeing damage done to Pentagon (penetrating four stone veneer wings ((8 sides)) plus the internal walls etc.). I don't want any Chernobels in the U.S.

The year is 2025 and your standing in a typical us city at night.

Everything is bathed in a green glow... comming from a towering set of windmills each covered in 1 million green leds and s mass of other colors to mark out a company logo.

The nearest behemoth sports a shell symbol 200 feet wide and at its base.. a tiny dot of light... a hydrogen fueling station with glowing green solar array on its roof... only required 50000 leds to light that... and a bunch of 20 foot tall glowing green obalisks with huge green H's glowing out so bright you can read by it 2 miles away. And no one argues no one complains because after all isnt it utterly completely green?

The city is happy as they no longer need streetlights. Shell is happy what h2 they do sell is the equice of selling the energy at 7 cents per kw.. and even when no sold as h2 its still sold.

Ah a bright green world.... cant you see it?

Chernobyl wasn't caused by a plane...it was caused by faulty reactor design.

Stan, for once you may have a point. Some estimates of remaining coal and oil reserves suggest that GHG emissions this century will be less than any published IPCC future scenario. However other reserves estimates suggest coal could push GHG levels ever higher leading to runaway warming. You may not believe it but the vast majority of climate scientists do. We could leave everything to the market and cross our fingers that we run out of coal before we completely stuff the climate or we could be prudent and take a little more control over our future. Given that undesirable changes are already happening I think its kind of obvious which way to go.

As for KitP's 1% renewable being "too much to tolerate" - only for the tiny minority with vested interests in keeping the status quo. Who do you work for again Kit??

Many more Up-to-date nuclear power plants are almost unavoidable in the future power mix.

France has done it for many years and there are no economical, ecological or technical reasons why USA, China, India, EU etc could not do the same and get 80% to 85% of their electrical power from nuclear.

Burning fossil fuels and biomass to produce electricity should be limited to contain GHG.

Of course, PHEVs and specially BEVs will become the most favoured vehicles much faster that we think.

We will all see the day when most NA homes will have one (1) PHEV + one (1) or two (2) BEVs and NO ICE vehicles. Small BEVs will be better and much cheaper than current ICE monsters.

London (England) will soon have many thousands e-charging stations installed across the city. Most will be on the same support structure as the parking meters. Two in One service, on your debit or credit card. Clean, simple and efficient. Just punch in the KWh required or push the 'fill it up' button; the machine will do the rest. It may or may not thnak you for using clean electricity to power your vehicle.

Patrick

Damaging the inside of a containment building, not being able to lower damaged control rods, pumping system damaged ,etc ,would have the same affect as Chernobyl.

@ StanP: Isn't coal still quite a bit cheaper than nuclear, which, more than anything else was the reason nuclear wasn't popular for the last 3 decades in the US?

@ KitP: While nuclear will be part of the mix, the real question you raise is this: How do we store solar/wind/tidal/wave power for times when it is not shining/blowing/flowing, and what on-demand power generation is best for making up any shortfalls? Neither nuclear or coal can be turned on and off quickly if clouds blow over Nevada. I think natural gas is pretty favorable here. It is much cleaner than coal and utilities use natural gas cogeneration rigs to meet peak demand today. These are very modular as well. Yes, we probably need more LNG offshore terminals in the long run.

Another means of storing electricity being explored is vehicle-to-grid, which I find very suspicious, and believe would require a lot of intelligence in the system to make it worth the vehicle owner's while. I think it works best if an eestor ultra-superduper capacitor technology works for millions of discharge cycles, but we can not yet count on that (though it would be cool). The system for that might be charge your car during the day while you work, and live off of some of that charge at night. You probably only drive 30 miles a day anyway.

DoE buttheads routinely exclude nuclear power from their insightful researches for a reason.

Current price of electricity generation on US nuclear power stations is about 1.8 cents per Kwh (from coal - around 3.5 cents and from NG around 8 cents). Off-peak nuclear electricity to power no less than 20% of all US car/light truck fleet (if it magically goes all-electric overnight) is available immediately, without upgrade of transmission system, with a generation price of 0.5 cents per Kwh. It is about 10 cents per gasoline gallon equivalent, delivered and taxed, with ample profit margin. And yes, carbon footprint 20 times less than from coal electricity.

JIMR if it is so easy why do the terrorists blow up France's trains and not their nuclear plants?

Why didn't the terrorists attack a nuclear plant on 9/11 with one of their planes?

...and just how are you going to accomplish the damaging of the internals of a nuclear reactor? What numbers are you using (and software) to determine a plane could bring down a nuclear reactor?

Brazen, unsubstantiated fear is a large part of why there have been few nuclear power plants put into service in the US lately...high initial capitol investment is the other part.

Tell me, how many people died from 3 mile island? How many people have died mining uranium, storing waste material from a reactor or during operation of a reactor? The numbers for coal mines & power and other industries are astronomical in comparison to nuclear.

Eng-Poet posted: "I'm getting increasingly annoyed with Roger Pham. He uses claims like "140% electric efficiency" without considering that a great deal of energy would have to be supplied as heat from fossil sources. Maybe he's just ignorant, but he presents himself as knowledgable."

Here's a clue for you, Eng-Poet: The gas turbine power plant of the future will be powered by HYDROGEN stored from excess summer solar or wind energy, and NOT necessarily from fossil fuel. Now, who is more knowledgeable?

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