Performance variant of Holden Commodore coming to North America as Chevrolet SS
Toyota to increase V6 engine production in Alabama

Mercedes-Benz eyeing introducing a sedan model hydrogen fuel cell vehicle around MY 2017

The 2011 F-Cell. Click to enlarge.

Mercedes-Benz, which has begun leasing of the limited production B-Class F-Cell hydrogen fuel cell vehicle (earlier post) in California, is on track to roll out a MY 2015 next-generation B-Class F-Cell in much larger quantities for sale, and is considering introducing a regular sedan-class fuel cell vehicle in around MY 2017, Sascha Simon, Head of Advanced Product Planning at Mercedes-Benz USA, said in an interview with Green Car Congress—perhaps an E-Class version, he suggested.

We are not intending to build a particular fuel cell sub-brand that looks and feels different. Our customers would like to drive our E-Class as a fuel-cell car. It [fuel cell technology] would work beautifully in a regular sedan shape—normal Mercedes luxury, but filled with pressurized hydrogen. I am completely convinced the technology has the potential to take over the internal combustion engine, together with pure battery EVs in their niche.

—Sascha Simon

Currently, Mercedes-Benz has 37 leasing customers for the B-Class F-Cell in Southern California, with suggested pricing set at $849 per month for 24 months. Several hydrogen fueling stations are now open in Los Angeles and surrounding areas, including Newport Beach. The F-Cell will become available for Northern California in June.

Although Mercedes-Benz has introduced a plug-in hydrogen fuel cell research vehicle—the F125! (earlier post)—which projects out about 20 years, Simon suggests that a pure fuel cell vehicle could be more price-efficient than a plug-in.

For me it comes down to the price point for batteries versus fuel cells stacks and how this plays out. If you obviously have a price premium for batteries that is not going down over the next ten years, I would argue that a pure fuel cell vehicle is more price efficient versus a plug-in. If you look to the plug-in world right now, the current numbers don’t bode so well. We haven’t see a drop in prices in batteries that we would like to see; we’re monitoring the price point and we’ll take it from there.

I do believe that it is as easy to build a fuel cell car as an ICE [internal combustion engine] car today—and we are almost there—without the need for plug-in capacity. This car [the B-Class F-Cell] is ready for mass production. It drives like a normal car. The HMI is built like a normal car. It’s not not science fiction, not a prototype. They are real-world cars on lease.

—Sascha Simon

“Really now the biggest topic is the available infrastructure. That is really the only hold up there is—there is no other reason why we are not rolling out more of these cars. The new legislation [the Advanced Clean Cars package in California, earlier post] will help very much.”
—Sascha Simon

B-Class F-Cell. The front-wheel drive B-Class F-CELL offers an operating range of around 240 miles (386 km) on the European driving cycle, or 190 miles (306 km) estimated EPA, and a 3-minute refueling time.

The technical basis for the drive system of the B-Class F-CELL is a second-generation fuel cell stack from Automotive Fuel Cell Cooperation (AFCC)—a Canada-based joint-venture private company between Daimler AG (50.1%), Ford Motor Company (30%) and Ballard Power Systems (19.9% ownership and a financial investor). AFCC serves as a fuel cell center of excellence for the two OEMs. The second-generation stack in the B-Class F-Cell features a power increase from 65 kW to 100 kW, increased lifetime and reliability, and freeze start ability below 0°C.

(In March 2011, Mercedes-Benz announced that it would set up its own production of fuel cell stacks in Vancouver, British Columbia—home of AFCC. Construction of the plant is underway, Simon noted.)

The B-Class F-Cell also features a 1.4 kWh Li-ion battery pack and a compressed hydrogen storage capacity of 3.7 kg at 700 bar. The 136 hp (101 kW) electric motor develops 214 lb-ft (290 N·m) of torque; the B-Class F-CELL uses a single-speed gear reduction transmission w/reverse and recuperation.

The vehicle accelerates from 0-60 mph in 11.4 seconds, and has a top speed of 106 mph (171 km/h). Estimated fuel economy is 52 miles/kg of hydrogen on the city cycle, 53 miles per kg on the highway.

Progress in fuel cell power density. Source: AFCC 2009. Click to enlarge.

Next-generation fuel cell work: costs. Overall, Gen 3 fuel cell cars—e.g., the next-gen MY 2015 F-Cell—will demonstrate capabilities competitive with other platforms, but cost remains an issue, according to an AFCC research needs analysis presented in 2009. Accordingly, Generation 3 fuel cell stacks will focus on cost reduction. The Gen 4 stack—which would appear in the sedan application—will also focus on further cost reductions.

There are five basic strategies for cost reduction, AFCC says:

  • Less expensive components for balance of plan (BOP);
  • Fewer components;
  • Less parasitic power loss;
  • Less material in the stack itself; and
  • Less expensive material in the stack.
Platinum content reduction and power density. Source: AFCC 2011. Click to enlarge.

Given the high cost of platinum, new durable, high-activity (and lower-cost) catalysts are critical, AFCC says. Current mature technologies—such as carbon-supported Pt catalysts, current membranes, and current cell and plate designs—have reached their maximum capability, and the Gen 4 stack will utilize them at their maximum. Alternative paths or breakthroughs are needed.

Possible new pathways for cathode catalysts include stabilized platinum alloys; new catalyst-support (non-carbon) interaction (e.g., high surface area metal oxides or core-shell catalysts); pseudo bulk catalysts; and non-precious metal catalysts.

Possible new pathways for membranes include low-cost PFSA membranes; hydrocarbon membranes; or additive technologies—i.e., improving membranes by adding special functional materials.



the answer is simply: Because H2 is easy and cheap to make and can be made anywhere.
Even if true (H2 doesn't come cheap), we are finding out that lots of things other than H2 are about as easy to make; some of them are room-temperature liquids.  It's much easier and cheaper to store CO2 than H2, and that's assuming that we can't just pull CO2 out of the atmosphere when we want it.  It's much cheaper and more efficient to pump hydrocarbons or higher alcohols cross-country than hydrogen gas, and we have far more storage options for them.

These exchanges are like "we need hydrogen to provide X!", I ask, "what if hydrogen isn't the best way to provide X (example)", and all I get back is "we need hydrogen to provide X!".  Around and around with no conclusion on the merits.  This is EXACTLY what the discussion would look like if either (a) hydrogen was a solution in search of a problem, or (b) hydrogen is a diversion, were true (or both).

We have plenty of biological CO2 currently going to waste.  The CO2 in landfill gas is dumped, as is the CO2 from ethanol plants, bio-digesters and the decay of crop and forestry byproducts.  Even assuming a mere 50% potential capture of just the projected ag byproduct carbon in the USA, you'd get about 250 million tons per year or about 0.8 tons/capita/yr.  0.8 tons of carbon makes about 1.2 tons of isobutanol or about 1500 liters (~400 gallons).

Note that this isn't what you can afford to use; that's how much you can afford to use in ways which lose the carbon back to the atmosphere (e.g. aircraft, offroad applications, power tools).  Recaptured and recycled carbon would allow total fuel usage to be much higher than that.  Tankage for storing CO2 would operate at about 1/10 the pressure of H2 storage and require only about 70% of the volume per unit energy.

I'd like to ask: Why not H2?
I thought I told you:  H2 requires very high pressure storage, poses explosion hazards, and is far from the best transportable product we've got.
Direct use of H2 can reduce energy cost to 1/2 that of synthetic methane.
Documentation for this claim?

Note that the electric-archaea trick to turn CO2 directly to methane (80% efficient!) is being commercialized, and the recent electrolytic-formate-to-alcohols process is obviously just the first of a whole family of microbe-mediated electrochemosynthetic processes.  They appear to be both efficient and likely to be inexpensive.  Instead of making H2 as a process input for something else, we can make them directly.  Liquid fuels, plastic monomers, drugs, maybe even food.  Why make H2?

Hydrogen leakage may cause less O3 loss per molecule than CH4, but it takes about 3x as much H2 to do a job and H2 is far more prone to leak.

Furthermore, ethanol and isobutanol synthesis from waste biomass will be quite expensive
Expensive?  Humans electrolyze CO2 and water to formate ion, bugs do the rest.  Given the formate-to-NADH pathway, it's likely that this can be used to engineer organisms to make a great many products.  This is just the beginning.

Roger Pham

Please realize that my projected low cost of renewable-energy H2 is for the future, at least a decade from now, based on current trend of continual lowering of renewable energy.

However, I can give you a reference that will give you a good estimation of the cost of synthetic methane from biomass, depending on the cost of raw biomass:
In page 18, you will see that the cost of biomass S-methane is around 16-18 USD/mmBTU (293kWh)
The cost of biomass like wheat straw or hay is around $4-5/mmBTU. See:

Whereas, the cost of renewable-energy is mostly dependent on the cost of renewable-energy electricity. Right now, the cost of renewable-energy electricity is around $50-60/MWh. However, with the current trend of decline in the cost of renewable energy, in a decade or so, one would expect renewable energy like wind and solar to be around $25-30/MWh. Assuming $25/MWh, 78% efficiency of electrolysis + compression within the same electrolyzer, and 5% amortize cost of the electrolyzer = $9.8/mmBTU for renewable-energy H2.

If you would adjust for the higher efficiency of H2-PEM FC at 70% vs. the ~50% efficiency of molten carbonate FC (with internal reformation) or SOFC, or the most efficient ICE technology, then you can see that my rough claim of the 2x cost-effectiveness of direct H2 utilization is not off the mark.

Thanks for sharing the info on carbon capture and storage, but please keep in mind that all these came with extra co$t$ and efficiency lost. When the H2 is stored underground like you would store methane, I don't expect that H2 would be any more difficult to store than methane. The high pressure requirement issue of storing H2 onboard a vehicle is not a show-stopper, as this MB FCV demonstrates in this article.

But, granted, you are right that, at the present, there is no cost advantage of renewable-energy H2 vs. synthetic methane from waste biomass. It is always difficult to accurately predict the future, but is always fun to try to speculate anyway:)

I can give you a reference that will give you a good estimation of the cost of synthetic methane from biomass
I'm not talking about methane from biomass.  I'm talking about methane and/or liquids from electricity and CO2; the observed efficiency of methane production from CO2 and electricity is 80%.  We can probably assume that the efficiency of production of higher alcohols will be similar.

At $25/MWh electric cost, the energy cost of methane from CO2 would be $31/MWh or about $9/mmBTU.  That's about the same as your price of hydrogen, and methane is more easily stored and transported; if 4- and 5-carbon alcohols are made instead, they can be shipped around in existing pipelines and trucks and stored in existing tank farms.

Note that NETL estimates about $1.10-1.60/kg for hydrogen produced from coal, or $9.70-$14.00/mmBTU including plant amortization.  Hydrogen from RE is going to have a hard time competing against hydrogen from coal, let alone natural gas.

If you would adjust for the higher efficiency of H2-PEM FC at 70% vs. the ~50% efficiency of molten carbonate FC (with internal reformation) or SOFC
SOFCs are up to 65% demonstrated electrical efficiency, plus the high-grade waste heat can do things that PEMs can't.  This is roughly on par with PEM FCs, and even better for some purposes.
Thanks for sharing the info on carbon capture and storage, but please keep in mind that all these came with extra co$t$ and efficiency lost.
All the high-pressure systems, pipelines and so forth for hydrogen co$t$ money too, and there's a lot less from the existing system that we could re-purpose.

What I'm really concerned about is that hydrogen is just a way to entrench coal and natural gas as our vehicular energy supply for another 50 years, because they are the most favorable raw materials for that particular product.  I don't think we can afford that.  An "electricity first" effort gets us 2/3 of the way there without trying too hard, and we can quibble about the rest at our leisure.

Roger Pham

Two problems, E-P, with microbial methane synthesizer:

1) Since 2009 from a laboratory report from PennState U., there are no report to verify PSU's finding, nor any larger-scale demonstration in term of feasibility for industrial scale. The 80% efficiency is PSU's Logan's team own report without any further peer reviewed nor duplication of their work. Science does not work that way!

2) CO2 capture and storage costs 25% of the energy output of a coal power plant. See:

Direct CO2 removal from the air will cost even more energy, if not at least that much.
If you would include this efficiency loss into the 80% efficiency of PSU's microbial CH4 synthesizer, the efficiency would be far worse than commercially-proven H2 electrolyzer. Removing pure CO2 from an exhaust stream of an energy producer is neither simple, or cheap, nor without significant material and energy investment!

What I presented to you in term of waste biomass to methane synthesis with addition of renewable-energy H2 to double the methane yield of waste biomass is a far more proven and more efficient way of synthesizing methane from renewable energy! If you wanna use methane as a fuel instead of direct H2 utilization, at least use a process that is already proven industrially like I had presented to you, instead of an unproven, un-peer-reviewed, isolated laboratory report that reeks of Pons&Fleischer's.

Since 2009 from a laboratory report from PennState U., there are no report to verify PSU's finding
Only 80 cites to the paper, including this reproduction and expansion on the results.

FWIW, I have to retract a claim here.  The conversion of electricity to methane is 80% electron efficiency, not 80% energy efficiency; the quantum figure must be divided by the input overpotential factor.  On the other hand, there is a lot more research showing that the previously mentioned results are fully valid and the basis for further advances.

Direct CO2 removal from the air will cost even more energy, if not at least that much.
All energy is not created equal.  Chemistry such as potassium carbonate can capture and recover CO2 using solar heat at 125°C or less, which is well within the capability of flat-plate collectors.  The "Green Freedom" scheme postulates CO2 produced as a byproduct of the electrolysis of potassium bicarbonate solutions; the evolved CO2 + H2 would require at least one additional H2 to make alkanes.

If vehicle-borne fuel cells can purify and store their product CO2 using their own waste heat, the argument about the cost of CO2 is rendered moot.  So long as it's recycled, nobody really needs to care what replacement costs.

This applies to alcohols too.  Alcohols store more easily than methane, which stores more easily than hydrogen.  Soda-water stores at lower pressures than CO2.  The arguments for the hydrogen economy need to address those for the hydrocarbon and alcohol economy, and I just don't see them getting anywhere on the merits.

The comments to this entry are closed.