June 2015
VIAVISION VOLKSWAGEN
SHAPING THE FUTURE OF MOBILITY
Fuell Cell Technology Clean Drive
VIAVISION
FUEL CELL
Seminal Development
Index Interview with Dr Heinz-Jakob Neußer
2
A Vision on its Way
3
Thoroughly Thinking Through
3
At the Heart of Hydrogen
4
This is What Hppens Inside
6
Well Connected?
8
Dr Heinz-Jakob Neußer on the Practicality of the Fuel Cell
Dr Heinz-Jakob Neußer, Board Member of Management for the Volkswagen Brand and Head of Powertrain Development of Volkswagen Group.
Imprint www.viavision.org Edited by Volkswagen Aktiengesellschaft Konzernkommunikation Brieffach 1972, 38436 Wolfsburg, Germany Phone: +49 (0)5361/9-87603 Fax: +49 (0)5361/9-21952 V.i.S.d.P. (Person responsible according to the German press law) Stephan Grühsem, Leiter Konzernkommunikation; Pietro Zollino, Leiter Produktkommunikation Marke Volkswagen Editorial staff Stefanie Huland, Michaela Möller Volkswagen: Michael Franke, Tonio Vakalopoulos Contact: redaktion@viavision.org Published by Verlag Rommerskirchen GmbH & Co. KG Mainzer Straße 16 -18, Rolandshof 53424 Remagen, Germany Phone: +49 (0)2228/931- 0 www.rommerskirchen.com Printed by L.N. Schaffrath GmbH Marktweg 42-50, 47608 Geldern, Germany All images in this issue are approved for reprint, citing VIAVISION as their source.
2
What are the biggest challenges to bringing fuel cell vehicles to the market? The major challenges for this technology are cost reduction and the establishment of the necessary infrastructure. Moreover, it is of fundamental importance that the hydrogen is produced from regenerative sources. This is the only way to ensure sustainable mobility. This technology is one of many possibilities for emission-free long-distance mobility. Are fuel cell vehicles already practical for everyday use? We have already demonstrated the practicality of our fuel cell vehicles in fleet trials. This was presented to the public at last year’s L.A. Auto Show. We showed there that this type of drive is suitable for everyday use. In addition, we have shown that our MQB is already prepared for fuel cell technology. Now, the task is to offer fuel cell technology at a marketable price. We are working in-
tensively on this. For widespread use in everyday life, however, the necessary infrastructure and commitment to hydrogen as an energy carrier are still lacking. Does Volkswagen actively support the establishment of a hydrogen fuelling station infrastructure? Volkswagen assists the activities of the H2-Mobility initiative in creating a hydrogen infrastructure in Germany. To me, it is important to emphasise that the public service obligation is not with the automotive industry. The development of an infrastructure to provide hydrogen must be made by energy companies and the petroleum industry with its petrol stations and, in the long run, support itself.
June 2015
FUEL CELL
A Vision on its Way Fuel Cell Vehicles by Volkswagen
The idea behind the fuel cell car is convincing: the same range and comparable refuelling time as a vehicle with a conventional drive with no pollutant emissions, like an electric car. The developers at Volkswagen have already been working on the concrete realisation of this vision for many decades.
2000
2001
VW Bora Variant Capri The first fuel cell vehicle from VW was an EU-funded project. Its fuel cell system ran on methanol, which was converted into hydrogen and CO2 on board.
2014
VW Bora HyMotion 1 The first HyMotion used liquid hydrogen as fuel. A large amount of energy has to be expended in order to convert hydrogen into this very dense state of matter. In the long run, this proved to be too energy-intensive and could not win through.
Volkswagen introduces other studies which are already fuelled with gaseous hydrogen. Apart from these technical developments, the VW Group is involved in initiatives such as the Clean Energy Partnership which paves the way for the market introduction of fuel cell technology, with partners from industry and politics.
VW U.S.-Passat HyMotion 4 The HyMotion 4 epitomises the current state of fuel cell technology. The US-Passat, presented in L.A., uses gaseous hydrogen as fuel for the fuel cell system, developed by Volkswagen, which is stored on board at a pressure of 700 bar.
Thoroughly Thinking Through The Fuel Cell Complements the MQB’s Powertrain
The Golf HyMotion, presented in Las Vegas, showed that the fuel cell can be implemented using the constructive base of the Modular Transverse Matrix (MQB) as well as making use of some of its components and technologies. This engine completes the line up of drive systems offered by Volkswagen based on the MQB.
All the Drive Systems in the Modular Transverse Matrix: Conventional Diesel
Petrol
Alternative/Renewable Ethanol
Natural Gas
Conventional/Electric
Fuel Cell Electric
Hydrogen
Existing modules from the MQB, such as the electric motor or the battery technology as a whole, can be used. The hydrogen fuel tanks have technological similarities with the natural gas tanks already in use. However, the higher pressure in the hydrogen tank (700 bar) compared to the natural gas tank (200 bar) requires a thicker carbon fibre layer than in the CNG tanks.
3
VIAVISION
FUEL CELL
At the Heart of Hydrogen The Basis: Modular Transverse Matrix (MQB)
As new and revolutionary as fuel cells may be - the developers still don’t have to start at zero. A fuel cell vehicle is powered by electricity, the same as an electric car. The drivetrain can therefore rely on the tried and tested e-modules and technologies of the Modular Transverse Matrix’s electromobility.
The DC/DC CONVERTER is responsible for setting the voltage, and thereby controlling the flow of energy between battery, fuel cell and electric motor.
Fuel cell stack
Media in- and outlet
Turbo compressor
The FUEL CELL STACK is the drive’s power plant. It consists of many individual fuel cells that generate electric power for the electric motor through a chemical reaction of hydrogen and oxygen. Additional units are necessary for the operation of the fuel cell stack, for example the turbo compressor and the media in- and outlet. They ensure, among other things, that the correct amount of air, hydrogen and cooling water is led into the cells.
The RADIATOR releases the heat produced during the energy conversion into the environment and in doing so cools the fuel cell. About 6o percent of the hydrogen is converted into electrical work in the fuel which powers the electric motor.
The HyMotion features a fully automotive drive with a 12,ooo revolutions per minute SYNCHRONOUS MOTOR taken from the drive of the e-Golf.
4
The Golf HyMotion has a SINGLE SPEED TRANSMISSION. The electric motor drives the front wheels via the transmission and the drive shafts to which it is connected.
June 2015
The LITHIUM-ION HIGH-VOLTAGE BATTERY stores the energy recovered through recuperation during braking. It also supports the motor in dynamic phases through so-called boosting. The prototype has a high-performance battery, which can also be charged via the fuel cell. Another option would be to install a charging socket with which the battery is externally charged at the outlet, providing a purely electric range of up to 5o kilometres.
FUEL CELL
The four FUEL CYLINDERS consist of an inner plastic and outer carbon fibre layer and store the hydrogen in the vehicle. To save space, they are located in the underbody of the vehicle.
Technical characteristics of the Golf HyMotion Electric motor
100 kW / 136 hp
Maximum torque
270 Nm
Range
approx. 500 km
0 - 100 km/h
10 s
Top speed
160 km/h
Battery energy content
1.1 kWh
The POWER ELECTRONICS are connected to the electric motor and the battery, and transform the electric current so that the electric motor sometimes works as a motor (which converts electrical energy into kinetic energy), sometimes as a generator (which converts kinetic energy into electrical energy). During engine operation, the power electronics transform the direct current of the high-voltage battery into a three-phase alternating current that drives the electric motor. In generator mode, it transforms the alternating current into direct current; this charges the battery.
5
VIAVISION
FUEL CELL
This is What Happens Inside How the Fuel Cell Works
Hydrogen and oxygen react to form water. The resulting energy is converted into electricity, driving the electric motor of the vehicle. The challenges when building a car are the development of a low-cost fuel cell technology, the appropriate infrastructure, and the production of hydrogen from renewable energies.
The Structure of a Membrane Fuel Cell: DIRECT CURRENT ELECTRON
OXYGEN O2 O2-
HYDROGEN H2
H+
H+
ANODE Anode Using platinum as a catalyst, the hydrogen gas which is supplied to the anode disintegrates into protons (H+) and electrons (e-).
HOT WATER H2O
PROTON-CONDUCTING
CATHODE
MEMBRANE
Membrane The membrane consists of a plastic material which only lets protons pass. The electrons must find a way around the membrane to reach the cathode with its electron shortage. The movement of charged electrons through a closed electrical circuit converts electrical energy into mechanical work.
Cathode Oxygen is supplied to the cathode via the bipolar plate. Here it forms water with the free protons (H+) and electrons (e-), using platinum as a catalyst.
Each fuel cell has two electrodes: the anode and the cathode. Between them is a thin membrane that works as a conductor for the protons (H+). So-called bipolar plates lie between the individual cells. There are grooves on the plates over which oxygen and hydrogen is led into the cells. The combination of several cells is also called stack.
2 H2+O2 = 2H2O 6
June 2015
FUEL CELL
Hydrogen Hydrogen is the first element in the periodic table of elements and the smallest atom. Its chemical symbol is H. It is one of the main components of water and is the most abundant element in the universe. The nucleus of the hydrogen atom consists of an electron and a proton.
Oxygen Oxygen is a non-metallic element, its chemical symbol is O. With around a 21 percent share of the volume of air, it is the second most abundant element in our atmosphere. It is highly reactive, as regards chemical reactions, meaning that it easily forms chemical compounds.
Features of the drive Short charge time A fuel cell car can be refuelled with hydrogen almost as fast as a natural gas car or one with a conventional combustion engine. Filling the tank takes between three and five minutes, depending on tank capacity. Long range Fuel cell vehicles offer a long range. A full tank of hydrogen will take you several hundred kilometres. Hybrid function The battery in the fuel cell car works similarly to a hybrid vehicle: it supports the motor in dynamic phases and is charged with energy (recuperation) during braking. The battery could be charged externally from an electrical outlet by installing a charging socket. This enables a pure electric range of about 50 kilometres.
G lossary Bipolar plates: Bipolar plates are the main mechanical component of a fuel cell stack: they connect the individual cells of the stack electrically and maintain the media feed. For this they must be very conductive and withstand chemical influences, high operating temperatures and high mechanical pressure in the cell.
Electron: The electron is an electrically negatively charged particle and is part of the components of an atom, as are the neutron and proton. It is located in the electron shell. A body is negatively charged if there is an abundance of electrons. Proton: The proton is a positively charged particle and a part of an atom like the neutron and electron. It is located in the nucleus, with the neutrons. If there is a proton predominance in a body, it is positively charged. Voltage: Current flow requires voltage. The voltage level determines how much current can flow. Voltage is therefore the driving force that causes the movement of charge carriers. The voltage level is specified in volts.
7
VIAVISION
FUEL CELL
16 13
In operation
17
In concrete planning
15
Location search/ negotiations
Well Connected? Infrastructure of Hydrogen Filling Stations
Under construction
Well-developed environment-friendly technology is useless without the corresponding infrastructure. The same applies to the fuel cell: while scarce thus far, the expansion of hydrogen fuelling stations in Germany is slowly picking up speed.
4
HAMBURG A1
5
BERLIN A7 A9
COLOGNE A4
A4
A3
2
A1
KARLSRUHE 2
2
A7
A9
MUNICH
A3
In Germany, you can fill up on hydrogen at 16 stations today. By the end of 2015, that number should be increased to a full 50, as industry partners and the German Federal Ministry of Transport agreed in June 2012 as part of the National Innovation Programme for Hydrogen and Fuel Cell Technology (NIP). In order to deliver fuel cell drive coverage, about 1,000 such stations are required.
8