Hi guys! Saw this article on BMW saying, hydrogen is the next best thing – from electric cars.
Can anyone ova here, explain in a nutshell how hydrogen cars work? How it’s stored? How it’s made / refined heard its (h2o something)?
The safety of it, in case of an accident?
The transportation of the liquid?
Also, can hydrogen cars accelerate as quick as the Tesla’s? 😯
Thanks!
In: Engineering
Hydrogen and oxygen really want to combine to make water, a chemical reaction. Chemicals also have electric voltages, and if you do the reactions with the right materials around them you can make electricity flow. This is how batteries and fuel cells work. The difference is that batteries are closed up like a pouch. Fuel cells are more like a living thing, you feed fuel in and get waste out. For a hydrogen fuel cell you feed hydrogen and oxygen in and get water out as waste.
The most common way to get hydrogen is to break up methane, which is CH4. This take energy to do, so in a way you are storing energy by separating hydrogen out, and then releasing energy when you react it with oxygen. We can also use electricity to directly split water into hydrogen and oxygen, but this takes more power and so is less common.
If you take some water and put in 100J of energy to split it into hydrogen and oxygen, and then put that into a fuel cell, you will get 25J of electricity back out. This is not very efficient, lithium ion batteries can be around 90% efficient. The advantage of hydrogen is that it is more energy dense. 100J of stored hydrogen is a lot less weight than 100J of charged lithium ion battery. The advantage becomes less when you consider the weight of the high pressure hydrogen tank you need to store it because it is a gas, you need to cool hydrogen to almost absolute zero to make it a liquid.
Latest Answers