Question: Are there limitations with cars that run on hydrogen? For example can they go as fast as petrol cars? are they efficient? Do you think that petrol heads will accept the change from petrol to hydrogen? and... wow i have too many questions but do you think that in the future petrol cars will not exist? How soon do you think that will happen?

Josh Makepeace answered on 18 Jun 2013:

Hey 07stoombs! Thanks for all the questions!! Too many questions is not a thing – keep asking 🙂

Okay, I’ll try to get to all of the questions. There’s no reason why a hydrogen car couldn’t perform just as well as a petrol car. In fact, each kilogram of hydrogen releases about three times as much energy as petrol, so I imagine you could actually get more power from a hydrogen car! There are two main problems at the moment – although each kg releases more energy, hydrogen is a gas, so storing enough hydrogen in your car to allow you to drive for as far as you can in a petrol car is really tough. That’s the work I’m doing – trying to make materials which can store loads of hydrogen.

The other main limitation on hydrogen cars at the moment is that they’re really expensive, around $100,000 in the US! So we need to get the price to come down before they could be used widely.

I think that petrol heads will hopefully accept hydrogen cars. They’re going to be pretty high-tech, so I think that would appeal to people who love cars. The only thing I worry about is that hydrogen cars aren’t going to make as many satifying car growling noises as petrol cars. Maybe they could put some kind of noisemaker in!! 😛 As far as efficiency goes, hydrogen fuel cells are actually quite a bit more efficient than petrol cars (Petrol cars are about 20-30% energy efficient, and hydrogen cars are 40-60% efficient).

I think it’s going to be quite a while before petrol cars aren’t used, probably many decades. I think It depends a bit on where you live. In Japan, they’re starting to build lots of hydrogen cars from 2015, so some people will certainly be driving hydrogen cars in the near future. But in some other places, like the US, I think that there’ll be lots more cars that run on gas, which produces less pollution than petrol. There are also probably going to be some electric cars in the mix too, with petrol or gas electric hybrid cars.

So, I guess if I had to make a prediction, then over the next 10-20 years you’ll probably see a mixture of car types, then after that, hydrogen vehicles will become more and more common.

Hope this goes some of the way to answering your questions – if I’ve left anything out, let me know 🙂