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4Car has had one of the first drives in a fuel-cell car - a modified Vauxhall Zafira called HydroGen 1. The Zafira is well-suited to the fuel cell, because it has enough room to accommodate all the elements.
Despite the differences between a conventional engine and a fuel cell, the critical components of HydroGen 1 are placed in a very similar position to their petrol counterparts. So up front is the fuel-cell stack, the various regulators for the electricity it generates, the electric motor and the reduction drive. There's no gearbox, because an electric motor has a flat torque (pulling power) 'curve' that starts instantly from the maximum figure. Surprisingly there's a radiator too, but that's needed to keep the stack cool. Excess heat is created by the chemical reaction that generates electricity at about 80 deg C.
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Under the rear seats is the high-tech, insulated hydrogen tank and behind that a high-voltage battery. This eats into boot space, raising the floor by about six inches. It's there to smooth out the electricity flow to the motor, but GM hopes to lose it on future production models. At first glance the HydroGen 1 has a curious nose-down, tail-up stance. That's because the nose is heavier by about 150 kg - and this prototype hasn't got modified suspension to compensate. That is the only weight penalty over the 1425 kg diesel Zafira, but unfortunately the HydroGen 1's motive unit doesn't have the power to overcome it. The 200-cell stack under the bonnet may be good for 107 bhp of constant power, with an 'over-boost' of 160 bhp temporarily available, but that's in direct current (dc). The HydroGen 1's electric motor uses alternating current (ac) because ac motors are more compact and cope better with large amounts of energy. As such, the motor is rated at just 73 bhp, which is why performance figures are unlikely to set the pulse racing. Zero to 62.5 mph is a claimed 16 seconds and the top speed a paltry 87.5 mph.
From behind the wheel, the HydroGen 1 looks pretty familiar, but there are a few oddities in the cockpit - most notably the absence of a gearlever, clutch pedal or handbrake and a kW meter instead of a rev-counter. Where the gearlever would normally be are four black buttons with white graphics; the front one is an arrow pointing forwards, in the middle are an 'N' for neutral and a 'P' for park, and at the rear is an arrow pointing backwards. These are the drive selectors.
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