With battery power still showing many serious downsides for use in high-performance bikes, motorcycle manufacturers are on the lookout for alternative fuels. Kawasaki showed one option off at the Suzuka 8-Hour endurance race event in Japan last month, with the first public running of its hydrogen combustion engine-powered H2SX machine. The bike looked good, in a space-age fashion, and certainly ran well around the Suzuka circuit.
As a massive engineering conglomerate, Kawasaki Heavy Industries has more access to hydrogen know-how than many other manufacturers: it makes spacecraft, an industry where hydrogen is vital for powering rockets. So it certainly knows all about the downsides of hydrogen, one of which is that it’s not very energy dense, so it takes up a lot of space as a gas, which is why the H2SX has massive panniers fitted with high-pressure gas cylinders. The alternative method, of storing it in super-cold liquid form, needs complex cryogenic equipment that would be impossible on a bike. Hydrogen also attacks many metals, including steel, causing cracking as the tiny gas molecules creep between the metal’s atomic structure and make it brittle. Leaks are, of course, a serious problem in terms of fire and explosion risks.
However, the biggest problem for mainstream hydrogen power is where to get it. You can’t easily drill it out of the ground, so you have to make it either from fossil fuels, which is pointless if you’re looking to reduce carbon dioxide emissions, or by using renewable electricity – solar, nuclear, wind – to electrolyse water into oxygen and hydrogen. This is extremely wasteful in terms of energy, though: from 100kW/h of solar energy, you might lose up to 80kW/h in waste heat by converting water to hydrogen, compressing and piping it, then burning the gas in an internal combustion engine. By comparison, using that 100kW/h to charge a battery in an electric car or bike via the existing electric grid could lose only 20kW/h in waste.
Cars are already on the way to battery power it seems, and if they’re not moving to hydrogen, there will be no supply network for bikes to use anyway. If there’s a way for hydrogen to become useful though, you would think firms like Kawasaki will be the ones to come up with it.