Honda debuts all-new FCX Clarity advanced fuel cell vehicle

Featuring tremendous improvements to driving range, power, weight and efficiency – and boasting a low-slung, dynamic and sophisticated appearance, previously unachievable in a fuel cell vehicle – the FCX Clarity marks the significant progress Honda continues to make in advancing the real-world performance and appeal of the hydrogen-powered fuel cell car.

Honda plans to lease the FCX Clarity to a limited number of retail consumers in Southern California, U.S., with the first delivery taking place in summer 2008. Full details of the lease programme will be set closer to launch, but current plans are for a three-year lease term with a price of $600 per month (approx £290), including maintenance and collision insurance.

How the FCX Clarity got its name

Honda chose this name to express the idea that the company is creating a fuel cell vehicle that will offer a clear solution to the challenges of the future, helping society achieve sustainable mobility.

How the FCX Clarity works

The FCX Clarity utilises Honda’s V Flow stack in combination with a new compact and efficient lithium ion battery pack and a single hydrogen storage tank to power the vehicle’s electric drive motor. The fuel cell stack operates as the vehicle’s main power source. Hydrogen combines with atmospheric oxygen in the fuel cell stack, where energy from the reaction is converted into electric power used to propel the vehicle. Additional energy is also generated through the capture of kinetic energy from vehicle braking and deceleration (known as regenerative braking), which is stored along with surplus energy from the fuel cell in the lithium ion battery pack, and is used to supplement power from the fuel cell, when needed. The vehicle’s only emission is water.

Honda V Flow FC Stack

The V Flow FC Stack features an entirely new cell structure that achieves a higher output of 100kW, smaller size and lower weight, with a 50 per cent improvement in output density by volume, and a 67 per cent increase in output density by mass, compared to the previous Honda FC stack.

V Flow FC Stack (Vertical Gas Flow Cell Structure)

The new V Flow FC Stack introduces a cell structure in which hydrogen and air flow vertically, and gravity is used to facilitate more efficient drainage of the water by-product from the electrical generation layer. The result is greater stability in power generation. The new structure also allows flow channel depth to be reduced by 17 per cent – a major contributing factor in creating thinner cells and a more compact stack.

Wave Flow-channel Separators

The V Flow FC Stack incorporates wave flow-channels for the hydrogen and air, with horizontal coolant flow channels weaving between them. The wave flow channels provide greater flow length per channel than straight channels, while the resulting turbulent flow within the channel promotes improved hydrogen and air distribution. As a result, the hydrogen and air are spread over the entire electrode layer, making more efficient use of the compact electrical generation layer and achieving approximately 10 per cent higher generating performance than with straight flow channels. The horizontal coolant flow also ensures more even cooling over the entire electrical generation layer, allowing for a reduction in the number of cooling layers to half that of previous stacks. While the previous stack had one cooling layer for each cell, the new stack needs only one cooling layer per two cells. This results in a 20 per cent reduction in stack length and a 30 per cent weight reduction, which is a major breakthrough in compact, lightweight stack design.

Improved startup capability at low temperatures

Improved water drainage due to the V Flow cell structure facilitates better output immediately after startup. The reduced coolant volume and single-box design made possible by the wave flow-channel separators result in heat mass 40 per cent lower than previous stacks. As a result, startup is now possible at temperatures as low as -30° C.

Honda V Flow fuel cell platform

The FCX Clarity’s revolutionary new V Flow platform packages the ultra-compact, lightweight and powerful Honda V Flow fuel cell stack – 65 per cent smaller than the previous Honda fuel cell stack unit – in the vehicle’s centre tunnel, between the two front seats. The compact size of the new V Flow FC Stack allows for a more spacious interior and more efficient packaging of other powertrain components, which would otherwise be unattainable in a sleek, low-slung sedan.

Source: Honda