David Wenger has worked on the development of both battery electric vehicles and fuel cell vehicles for more than a decade. He believes that both technologies will be necessary in the future. Furthermore, David was a customer and driver of a fuel cell vehicle for 1.5 years. Now, he has been a Tesla Model S 90D driver for more than one year and uses it in his daily business. In this presentation, he will talk about his experience as a developer AND customer of both technologies and show where the “To Dos” are. MORE INTERESTING WEBSITES: www.wenger-engineering.com www.h2-experts.com

1. CCSHFC 2018 Birmingham
David Wenger
Tesla vs. Fuel Cell Vehicle – My Experience
13. March 2018

2. Why Wenger Engineering?
„The efficient and effective usage of fossil
energies and resources are the most
important challenges of mankind.
Wenger Engineering develops technologies to
solve these problems.
Our customers will save energy, weight,
volume and, at the end of the day, also
significant amounts of money.“
Dr.-Ing. David Wenger, Founder and CEO
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3. Key Facts
• Engineering company with a team of ~25
passionate professionals and trainees
• Headquarters: Ulm, Germany
• Services:
 Thermodynamics, Heat and Mass Transfer
 Fluid Mechanics, CFD Simulation
 Chemical Engineering
 Simulation Software Development
• Software:
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4. 4
Our Customers
Tesla_vs_F-Cell_CCSHFC2018_Birmingham 12.03.2018

5. State of the art: This was my old C-Class
• 270,000 km in 8 years
• First repair at 250,000 km
• Total repair cost at 270,000 km: ~250 €
• Total unavailability time due to repair:
1,5 days / 8 years
• Number of successful refuellings:
approx. 350
• Number of unsuccessful refuellings: 0
• Average extra time for fuelling: ~ 5 min
to get to the station + ~ 5 min for fuelling
and paying
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 This is my level of expectation for any car from now on!

6. 2014/2015: I had a Mercedes-Benz F-Cell
• I was among the first REAL customers in
the world to have a fuel cell car!
– We were NOT part of an R&D project
– We are NOT a ministry,
– NOT Hollywood actors and
– NOT a Global player
– We were normal customers
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• Every month, I paid money to use this car (this is another good reason to
have high expectations…)
 After 10 years in FC / H2 development projects, this experience
changed my point of view on some aspects
 The overall experience was good, but a (simple!) conclusion was: A
good drivetrain with a zero emissions fuel does not mean it‘s a great car.

7. 1.5 Years of Real World Refuelling Experience
• I always felt safe
• Most of the time, refuelling worked
• If it didn‘t work, it was usually due to
„stupid“ errors:
– Card reader errors
– Communication dispenser-shop
– Wrong operation of previous user
– Station capacity was low, therefore
low SoC
– Maintenance, even though I was told
the station is running
• No error I know of happened due to 70
MPa-T40precooling-J2601-rocket-
science-technology
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 A lot of progress has been made since then, especially on reliability

8. Since November 2016: Tesla Model S 90D
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 Is it a good car? Absolutely. Is it a great car? No doubt. Would I buy it
again? Without hesitating.
 However, Elon Musk is the only person in the world (it seems) who
has understood that a “future car” is more than a drivetrain.

9. Five Teslas waiting in line at a Supercharger
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 Yes, that’s reality. Most Superchargers are idle most of the time, but
this one is very busy. There is no solution except: “More Superchargers”.
 Full article: www.linkedin.com/in/dawenger/

10. Tesla consumption in winter
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 Average consumption (full year): 21.4 kWh/100km (= 0.65 kg of H2 or
1,9 l of gasoline)1
 Typical consumption in winter for short distances: > 30 kWh/100km
(range goes down from 450km to ~300km)
 Full article: www.linkedin.com/in/dawenger/
1 Avg. Consumption F-Cell: 1.18kgH2/100km

11. Do I have a right to charge?
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 Unfortunately, this is a common situation (at least in the area where I
live) – and there is nothing you can do about it.
Full article: www.linkedin.com/in/dawenger/

12. Conclusions
• After 15 years of EV and H2 development experience and four years as a customer,
here are some conclusions:
• Tesla:
– My Tesla Model S 90D is a great car – because of the drivetrain, but also
because of the whole car concept
– Recharging is much easier than expected – but sometimes it‘s a disaster
– Typically, I charge at home (no special equipment, 3kW). This is absolutely fine
95% of the time.
– I need the Superchargers from time to time. The experience is good.
– Destination charging in hotels is crucial
• F-Cell B-Class:
– It was a good drivetrain, I had no problems at all
– A lot of progress has been made with respect to H2 infrastructure in Germany in
the last years.
– However, it was „only a B-Class“ – not a fancy car that would support my
company marketing (or so)
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 Now the question is: Where are the Fuel Cell Vehicles that everybody
wants to buy?

13. Get your free E-BOOK
„Are Fuel Cells Fool‘s Cells?“
by
David Wenger
on
www.h2-experts.com
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14. Dr.-Ing. David Wenger
Wenger Engineering GmbH
Einsteinstr. 55
89077 Ulm, Germany
+49 731-159 37 500
mail@wenger-engineering.com
www.wenger-engineering.com