Tony Seba’s six arguments against fuel cell vehicles

Tony Seba is a Stanford MBA with a BS in Computer Science from MIT currently residing in Northern California.  Quoting from his blog, “Tony Seba is the author of Clean Disruption of Energy and Transportation, Solar Trillions and Winners Take All, a serial Silicon Valley entrepreneur, and an instructor in Entrepreneurship, Disruption and Clean Energy at Stanford’s Continuing Studies Program. His work focuses on clean energy, entrepreneurship, market disruption, and the exponential technology trends, business model innovation, and product architecture innovations that are leading to the disruption of some the world’s major industries, such as energy, transportation, infrastructure, finance, and manufacturing.”

On January 15, 2015 Mr. Seba published a post on his blog listing six reasons why fuel cell vehicles (FCEVs) will be unable to compete with battery electric vehicles (BEVs) when they are introduced into Northern California.

A little over a year later several hydrogen stations were opened in the San Francisco Bay Area and Toyota began shipping its first few FCEVs, namely the Toyota Mirai.  This is therefore an appropriate time for a preliminary comparison of Seba’s six speculations with the reality of FCEV “tires on the road”.  Here they are, with the first two switched.

1) Electric Vehicles are at least three times more energy efficient than Hydrogen fuel cell vehicles.

2) Hydrogen is not an energy source.

3) You need to build a multi-trillion dollar hydrogen delivery infrastructure.

4) Hydrogen is Not Clean.

5) Hydrogen is not ‘Renewable’!

6) Hydrogen Fuel Cell Vehicles can’t compete with Electric Vehicles.

Here are my responses.

1) Electric Vehicles are at least three times more energy efficient than Hydrogen fuel cell vehicles.

Half right.  Seba’s factor of three in energy efficiency obtains for his “well-to-wheels” analysis.  When any such analysis is split up into “well-to-tank-to-wheels” it quickly becomes apparent that the huge variability of well-to-tank efficiency allows one to cherry-pick whatever values yields the desired ratio.

The advantage of tank-to-wheels efficiency is that the EPA has official numbers, namely the miles-per-gallon-equivalent, MPGe, for every vehicle.  A gallon-equivalent is defined as the energy obtained by combustion of one US gallon of gasoline, taken for definiteness to be 121.3 megajoules (MJ).

The various Model S Tesla BEVs have a very impressive fuel efficiency of 90-100 MPGe depending on the exact model.  The Toyota Mirai FCEV has a less impressive fuel efficiency of 67 MPGe.  In the tank-to-wheels analysis the Tesla therefore beats the Mirai in fuel efficiency, but only by a factor of 1.5, not 3.  What happens between the “well” and the “tank” is nowhere near as clear-cut and therefore not a sound basis for comparison.

2) Hydrogen is not an energy source.

Neither are rechargeable batteries.  How is this an argument against FCEVs?

3) You need to build a multi-trillion dollar hydrogen delivery infrastructure.

To accomplish what? In round numbers, a million FCEVs could be serviced by 10,000 stations costing $1M each, for a total of ten billion dollars. Hence if you replaced all 250 million registered vehicles in the US by FCEVs the 2.5 million stations needed would cost a total of 2.5 trillion dollars. At that volume it would be reasonable to expect the average FCEV to cost $20K, bringing the fleet cost to 5 trillion dollars or double the cost of the fueling stations.

But this won’t happen overnight. Instead both FCEV manufacturing capacity and hydrogen delivery capacity will each grow at rates that can only be speculated at today. California for example currently has 20 hydrogen stations, with $200M earmarked for development of many more.

Today’s oil-based fueling infrastructure for ICEVs (internal combustion engine vehicles) does indeed require a complex infrastructure for importing, refining, and transporting fuel around the country. The US does not need a massive infrastructure for importing and refining natural gas, and tra

BEVs and FCEVs have in common an important difference from ICEs, namely that they can be operated entirely off the grid when powered by solar PV.

Actually the opposite.  Unlike the centralized extraction and refinement of fossil fuels, hydrogen can be manufactured locally from natural gas (whose delivery infrastructure is already in place) or by electrolysis using electricity from either the grid (also already in place) or solar PV (no infrastructure needed at all).  Regions served by hydrogen plants can be as small as counties, cities, or even individual refueling stations.

4) Hydrogen is Not Clean.

The five currently operational True Zero hydrogen stations in the San Francisco Bay Area claim to be one-third renewable with plans to increase that.  Electricity from PG&E is only 20% renewable with plans to reach one-third by 2020.  BEVs recharged from the grid are therefore even less clean than FCEVs refueled at one of the five (soon to be seven) True Zero stations in the SF Bay Area.

5) Hydrogen is not ‘Renewable’!

How is this different from objection 4) ?

6) Hydrogen Fuel Cell Vehicles can’t compete with Electric Vehicles.

True enough for a Tesla in “ludicrous” mode.  A Mirai patrol car would look silly trying to catch a bank robber in a P85D.

But there are many competitions besides raw power, such as the capacity CAP, weight WGT, and energy density DEN of the “tank”, the range RNG after filling up, and the refuel time RFT.  For most buyers comparing BEVs and FCEVs, range and refuel time are likely to be the main and perhaps only concerns, far outranking energy efficiency in importance.  The units for these are as follows.

CAP: Tank capacity (MJ)
WGT: Tank weight (kg)
DEN: Density of storage (MJ/kg)
RNG: Range in miles (per EPA)
RFT: Refuel time in miles per minute
STN: Stations in the SF Bay Area

The following table compares the Tesla 85 and the Mirai for each of these.

…….. Tesla   Mirai
CAP     306     710
WGT     544     143.5-87.5
DEN     0.56     4.9-8.1
RNG     265     312
RFT     0.6-10  62.4
STN     4       5

CAP: The Mirai stores more than twice the energy of the Tesla’s battery pack.

WGT: The Mirai’s tank weighs 87.5 kg (all that just to hold a mere 5 kg of hydrogen!).  Adding in the fuel cell stack, which has no counterpart in a BEV, brings that up to 143.5 kg.

DEN:  Density (specifically gravimetric energy density) is simply the quotient CAP/WGT in MJ/kg.

RNG:  Contrary to what one might expect from the very different tank capacities, the Mirai only narrowly beats the Tesla in range.  This can be blamed mainly on the fuel stack, which introduces a substantial inefficiency absent from BEVs, which as noted above have no counterpart.

RFT:  By far the biggest win for FCEVs is the additional 62.4 miles of range obtained with an additional minute of refueling, which adds 1 kg of hydrogen to the tank (so to fill from empty takes 5 minutes).  A Tesla charging at home on 240 volts gains only 0.6 miles per minute.  On a supercharger it does much better, gaining about 10 miles per minute.

STN:  There are very few hydrogen stations in the San Francisco Bay Area.  True Zero has opened five and will open two more shortly.  Other vendors have committed to several more.

What often goes unmentioned in these discussions is that the Bay Area has even fewer Tesla supercharger stations, namely four, two on each side of the bay.  The SF Peninsula has stations at San Mateo and Mountain View while the East Bay has stations at Dublin and Fremont.

The more substantive advantages of the Tesla over the Mirai are a nationwide infrastructure of superchargers, much faster acceleration, and a cleaner dashboard with a much larger display.  Tesla drivers should be able to expand this list, my experience is limited to the Mirai.

Lastly there is the small matter of cost.  The MSRP of the 2016 models of the Tesla Model S and the Toyota Mirai are respectively $71,200 and $58,491.  Both can be expected to decrease with increasing volume. The “race to the bottom” will be interesting to watch over the next couple of years.

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My new Toyota Mirai

On Thursday (5/19/16) I leased a Mirai from Toyota Sunnyvale (nearest Mirai dealer to my Palo Alto home).

Why Mirai?

1. ICEs emit many kinds of carcinogens into my neighborhood, see the book The Harmful Effects of Vehicle Exhaust described at Understandably this is not something either the auto industry or the oil industry is motivated to highlight as a beneficial feature of ICEs, and the consumer faced with the alternatives of public transport, a bicycle, or (gasp) a battery electric vehicle (BEV) is naturally in denial about it. Maybe hydrogen producers emit carcinogens, but not into my neighborhood AFAIK.

2. In 52 years of car ownership, including two new Mercedes, two second hand Mercedes, and a fleet of other vehicles from the UK, Germany, France, Sweden, Japan, and the US, it’s the first car I’ve ever owned that didn’t/won’t eventually drip oil.

3. Refueling time of 60 seconds per kg. That’s 4 minutes when your remaining range is 60 miles. It probably could refuel a fair bit faster in warm weather, this slow rate avoids the risk of icing up the nozzle in cold weather. When full (70 MPa = 700 atmospheres) it gives the remaining range as 342 miles, perhaps because it hadn’t yet figured out that I have a lead right foot. I’ve only had time for one refuel so far, I’ll keep an eye on it.

4. 300-340 mile range, adequate for me. I drive the 90 miles (in 90 minutes) from Stanford to the Stanford Hopkins Marine Station once a fortnight. Even though the nearest hydrogen stations to the latter are Campbell (66 miles to the north) and Coalinga (132 miles to the south, or 151 via I-5), there are currently two stations each within a mile of my normal route. While I wouldn’t normally do three round trips back to back, each of three hours (540 miles), I do have that option with this car—even with the longest-range Tesla I’d have to recharge at least twice on the way, however long that takes. For just the 90 miles, any BEV less than a Tesla may well have to recharge en route. And even with stations only just starting to come online in the last few months, already I could commute between Reno and Tijuana with stops for “gas” at just Sacramento, Coalinga, and LA. And if you want to take a 7-day vacation each year to places out of range of hydrogen stations Toyota kindly lends you a used Land Cruiser or whatever your trip needs (but you have to pay for the gas then, sigh).

5. Comfort of a loaded Lexus in a Camry form factor (but only four seats sadly). Everything in driver assistance short of keeping you in your lane if you fall asleep (it buzzes but that might not awaken you). Fully autonomous is still years away.

6. The price is right: including CA tax ($44/mo) plus optional GAP insurance and excess-wear-and-tear insurance ($47/mo), the driveaway payment after the $5k CA rebate is $500 (which I’d paid two months earlier as a deposit), the monthly is $499 + $44 + $47 = $590, and if after returning it (almost certainly) we get a different brand they ding us for $350 more. Fuel and service are free, but our insurer wants $1200/year for comprehensive coverage on top of that. Plus parking meters and toll roads.

7. Distinctive styling. I’m ok with it, and my Italian neighbors think it looks great compared to their conservative Highlander hybrid, which either reflects modern Italian styling tastes or they root for Darth Vader when they take their kids to see Star Wars movies. (Surprised George Lucas hasn’t already sued Toyota for infringing his stormtrooper design patent, but maybe he plans to get one—there’s a station near him in Mill Valley.) Anyway it’s only for three years, I’ll check out what Mercedes et al have on offer when the time comes.

8. Something about CO2 (insert belief here—infer mine from the 7.5 kW solar PV on my roof since 2008).

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Hydrogen as a Fuel

I started this blog for the purpose of collecting and evaluating opinions about the future roles hydrogen might play in the global energy economy.

Basics first.

Energy density

Hydrogen is one of a number of forms in which energy can be stored. Practical alternatives to hydrogen include gasoline, propane, natural gas aka methane (in either liquid or compressed form), and batteries. Less practical alternatives include TNT, dynamite, and C-4, which can store a great deal of energy that is however hard to release at a usable rate.

The hydrogen atom consists of one proton and one electron. This makes it by far the lightest of all elements in the periodic table, so light in fact as to make comparisons of gravimetric (by-weight) energy density meaningless.  Hence I’ll stick to volumetric energy, in units of megajoules per liter (MJ/L).

To make hydrogen storage practical it needs to be compressed, typically to a pressure between 35 and 70 MPa (5,000 to 10,000 psi). The latter is standard for the so-called hydrogen highway and is therefore what I’ll assume here.

The first five entries in the following table are from Wikipedia

Coal 35 MJ/L
Gasoline 32.4 MJ/L
Propane 25.3 MJ/L
Wood 13 MJ/L
Hydrogen 5.6 MJ/L
Panasonic NCR18650B battery 2.56 MJ/L (6800 of these cells used in the Tesla Model S)
Tesla Model S battery 0.77 MJ/L (based on 85 kWh/(84″x48″x6″))
Tesla 400 kWh battery 0.22 MJ/L.
Tesla 10 kWh Powerwall 0.18 MJ/L
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