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Ronald Hodkinson of Diverse Energy Ltd was very impressed by FC Expo 2010 which was held this spring in Tokyo. This is currently the largest fuel cell exhibition in the world with over 500 exhibits. The show and conference were very well attended, with 47 countries participating and the conferences oversubscribed. In this report we will attempt to give an overview of the main developments and trends. In the Fuel Cell Exhibition there were two major developments first, the Honda FCX Clarity Car and secondly, SOFC by New Energy Foundation, Japan‟s CHP Group.
HONDA’S FUEL CELL CHALLENGES THE INTERNAL COMBUSTION ENGINE
The Honda FCX Clarity Car represents a major breakthrough in technology. You could see it, touch it and drive it - it really works! The car was available for test drives throughout the conference and we understand that two vehicles are coming to Europe for a demonstration program. This vehicle contains Honda‟s revolutionary Vertical Flow Fuel Cell Stack, which is the secret of its performance. The 52 litre stack weighs 67 kg and is 750mm long x 185 wide x 370 high. This stack gives 100kW peak power and up to 30kW steady state. The significance of this is that it is the first fuel cell to challenge the power density of an internal combustion engine. There are five major developments incorporated into this product and it is the totality of these that accounts for the exceptional performance:-
- The Membrane used is a JSR Corp Aromatic Membrane. This gives high current density and conductivity at an operating temperature of 95°C. An indication of the performance is the fact that the voltage is 0.66V per cell at 100kW peak power.
- The Cell Structure is 3-dimensional and gives the best effective plate area and exceptional cooling. We estimate the nominal active plate area to be around 300 sq cms. Honda calls this a Vertical Flow Fuel Cell Stack. The cooling has to be exceptional – at 100kW the stack dissipation is circa 50kW.
- The mechanical construction: long thin stacks with drawbars have long been a problem in mobile environments. Honda have solved this by using an aluminium rigid box girder for the case with spring packs at both ends. This prevents flexing when negotiating bumps in the road. One end of the stack has the gas services for H2 and air on a manifold. The other end has the busbars with water cooling and is attached directly to the DC/DC converter, which boosts the actual stack voltage to 270V for the lithium ion battery pack. At peak power around 20kW is consumed for air compression so the stack gives 100kW and the battery pack 25kW to give 100kW at the motor. Peak air pressure we understand is around 2 bar and is not enriched.
- Vehicle layout: the fuel cell stack sits in the transmission tunnel between the driver and passenger. The gas services face forward into the engine compartment where the air compressor/humidification/filtration systems are sited. The back of the stack goes to the DC/DC converter with the 270V battery beneath the rear seat. The cables then go forward to the inverter pack over the motor/transaxle front wheel drive unit. The motor is a brushless DC PM Design. The hydrogen gas tank is in the boot and operates at a service pressure of 350 bar and holds circa 7kg of gas - enough for 300-400 mile driving range dependent on conditions.
- Wide temperature range performance: the aromatic membrane operates from -30°C to + 95°C. The stack is designed for all water to drain down when shut down and this contributes to fast warm up at low temperatures.
HONDA’S FORMULA 1 TEAM TRANSFERRED TO FUEL CELL VEHICLES
Honda controversially pulled out of Formula 1 and put its team to work on fuel cell vehicles - a strategy that has more than paid off with the FCX Clarity. This development represents a huge step forward for Honda and the fuel cell industry. To overcome fuel supply problems, Honda offers a home electrolyser that permits high pressure hydrogen generation from a wall socket.
JAPAN’S CHP FUEL CELL PROGRAM
The next big thing was the development of SOFC at the New Energy Foundation - the Japanese Domestic CHP Fuel Cell Program. For the last seven years they have been developing a system based on PEM Technology and a steam reformer and several thousands are in the hands of Japanese consumers. This year has seen the introduction of high temperature solid oxide fuel cells, which brings Japan into line with other major players, such as Ceramic Fuel Cells. The reasons why this happened are as follows:
- Solid oxide works well in this application
- A single box reforms and produces power
- Clean water is not required for reforming
- System efficiency is higher with SOFC: 50% versus 40% on Natural Gas
- SOFC is cheaper to manufacture than the PEM/reformer System
- High temperature corrosion and life issues are slowly being overcome with SOFC
The New Energy Foundation has installed 132 SOFC units for trial over the last three years. The units operate on a variety of fuels - natural gas, LPG and kerosene. In all these cases the system efficiency has proved better than the PEM system, with natural gas giving the best results. We understand that the New Energy Foundation has not abandoned the PEM solution as recent developments at Honda show that further improvement in performance is possible. This situation is one of work in progress.
The main Japanese exhibits were from the Japan Hydrogen and Fuel Cell Demonstration Program and the New Energy Foundation. There were hundreds of smaller Japanese company stands promoting both stacks especially for bicycles and balance of plant equipment. The Japan Hydrogen and Fuel Cell „Ride and Drive‟ was particularly popular, with eight vehicle types available for test and the HINO/Toyota FC Bus ferried visitors to the local metro station throughout the show.
EUROPE AND OTHER COUNTRIES
So who was at the show from Europe? Germany, France and Finland had Pavilions. Ceramic Fuel Cells were on the German Pavilion as they have an SOFC production facility there.
From the UK, ACAL Energy had their own stand with their FLOWCATH System. This is similar to a PEM fuel cell but instead of a stack/humidifier there is a stack/regenerator. The cathode reaction takes place in the regenerator, a separate unit to the stack where water and air react with a proprietary liquid catalyst. Why do this? It is claimed this is a „No Platinum PEM Fuel Cell‟ but there needs to be more demonstration before any assessment can be made.
The other major European Stand was Morphic Technologies from Sweden. They exhibited a range of PEM stacks and fuel cell systems from 2 - 10KW and seem to be focussed on stand-alone systems. London‟s City University had a booth promoting positive displacement screw compressors. Other major Pavilions were the USA, Canada and Taiwan.
 RELATED TECHNOLOGIES, BATTERIES AND PHOTOVOLTAICS
What of the other Exhibitions? Fuel cells will be utilized alongside and complement battery electric vehicles, as well as renewable energy technologies. In the first ever Rechargeable Battery Expo there was a focus on batteries for traction and EVs. Pure EVs using nickel metal hydride (NIMH) or lithium ion will double the size of the global battery industry over the next 5 - 10 years and a wealth of mass production equipment was on display. One major theme was the emergence of traction batteries for rapid transit vehicles. On a smaller scale it seems that someone has finally cracked the problem of making a zinc secondary battery. POWERGENIX based in California launched their range of nickel zinc rechargeable cells in A-D packages at 1.6V.
Honda‟s latest solar hydrogen station for refuelling the FCX Clarity was recently opened in California
The Tokyo PV Expo had 1000 stands which is a testament to the size of this industry. The main theme was larger and better solar panels. The New World Standard is a 2 x 1 metre panel which gives 250Watts - 30V at 8.33A. A single panel charging 2 x 12V 200AH batteries can supply 100Watts to a home with no mains connection - enough for lights, fridge, computer and TV if used intelligently. Alternatively large arrays of panels can supply megawatt size installations. Ten manufacturers had 2 x 1 metre panels including Sharp, Kyochera and Indosolar. Sharp demonstrated their latest panel which boasts an efficiency of 35.8% when used in space - a new world record. |
