I posted this picture of the GreenGT H2 on the Flux Auto Facebook page and got a question about the details of the car and how hydrogen fuel cells work. This post will address all of those things. Lets start with the car. The H2 is made by a French vehicle R&D company called GreenGT. It will be racing in the 24 hours of Le Mans next year in the Garage 56 experimental car exhibition spot that was occupied by the Nissan DeltaWing this year. The chassis of the car is made by Welter Racing and their are two electric motors that produce 540 horsepower to drive the wheels to a top speed of 186 mph. The interesting part H2 comes from the energy storage system. The orange tanks on the side of the car hold enough hydrogen gas to power the car for 40 minutes at a time. The H2 has a high temperature Proton Exchange Membrane Fuel Cell (PEMFC) that produces 340 kw. To be more specific, the car carries 18 combined cells that produce 20 kw each with one functioning as a backup. The science behind fuel cells is that a semi-permeable membrane separates hydrogen gas and oxygen. This membrane only allows protons to pass through it. What happens is the electrons and the protons from the hydrogen gas split up. The protons pass through the membrane and bond with the oxygen to form water. The electrons travel down the membrane to be used as electrical energy. Here’s a video illustrating the chemistry:
The theory behind fuel cells is sound (i.e. they actually work), but practical implementation is still lacking. Currently they are only a little more efficient than combustion engines even though they come in a much bulkier package. Harvesting, transporting and storing hydrogen also presents it’s own set of problems. The general public tends to associate hydrogen with the Hindenburg and seem to think it’s an explosion hazard(the same was said about gasoline when we switched from steam powered cars). In reality, a hydrogen leak is actually safer than a gasoline leak. Hydrogen gas dissipates extremely quickly since the molecules are so light. You will lose the gas before it has a chance to detonate which is a lot safer than liquid gasoline pooling up under a leak. The quick dissipation of hydrogen gas is also what makes it difficult to store. Since it’s the smallest atom, it tends to find its way through other materials. Fuel Cells are a clean way of producing energy but face similar R&D barriers as the rest of the green industry.