Rosalind Davis joins us in The Vat and Fiddle from the University of Birmingham for the first SciBar of the year. She’s here to talk about whether hydrogen can really be the fuel of the future.
But why hydrogen? Well, it’s more efficient that petrol or diesel and it can give further range than electric powered cars. It emits only water at the point of use and it can be generated using renewable sources thus guaranteeing energy security.
Hydrogen fuel cells are made of a polymer membrane. As hydrogen electrons pass through this membrane we get energy and water produced. These cells have already been tested in cars, for example the post van at the University of Birmingham is powered by one. Meanwhile Toyota are preparing to release a hydrogen powered car to the mass market.
But since this all sounds so amazing, why doesn’t everyone already have one? Well there are two main problems with hydrogen:
Firstly, filling stations. While petrol stations are everywhere and a lot of places even have charge points for electric cars, there are very few places where you can get hydrogen (although if you do need to fill up in Nottingham, you can do so at the University of Nottingham)
Secondly, storage. People don’t really like having a compressed gas tank in their cars. The tanks are also incredibly expensive at the moment and the cost of the tank is a determining factor in the cost of the car. For example, the new Toyota will cost in the region of £45,000.
So, how can we store the hydrogen more efficiently? The problem is that the hydrogen atoms want to be as far apart from each other as possible. Hence we have the problem that if we store the hydrogen in the most efficient way, we are adding the equivalent weight of another passenger to the car.
Electrolyte fuel cells need to be in the region of 100 degrees to operate in order to be able to split the hydrogen in the first place. Lighter materials bond too well to the hydrogen so require more heat. So, we are left with a really difficult balancing act.
However, there have still been some notable successes. For example most of Walmart’s warehouses in America use hydrogen powered fork-lift trucks. Beijing and London both had hydrogen powered buses when they hosted the Olympic Games and the ones in London are still running. Fleet uses like these should be easier as it means that you can have a filling station at a central location.
While all of the big car manufacturers are using compressed gas, some are now looking at the possibility of using replaceable cartridges. This would be similar to gas bottles currently work. Elon Musk, the man behind the Tesla electric car isn’t convinced by hydrogen though. Maybe he’s right, maybe it won’t work in cars, maybe its future lies in something smaller. Perhaps that’s why Apple have taken out a patent for hydrogen fuel cell technology for the MacBook.
Talk from 27/02/2016
Published for the first time here