Musk says “The energy cost of methane is the lowest and it has a slight Isp (specific impulse) advantage over kerosene,” said Musk, adding that “it does not have the pain-in-the-ass factor that hydrogen has”

Apparently methane is the easiest to “harvest” off of Mars. Mars according to Musk is now possibly only 11 years off. (Best case scenario.)

The proposed replacement, hybrid H2 fuel cells, is a fantasy. Transitioning from a gasoline to a H2-based infrastructure requires investment of trillions of dollars and capital investment. Without huge subsidies, this transition will never occur.

Today there is a huge lobbing of LNG (liquefied natural gas) as a transport fuel, especially in Europe. LNG is not totally clean fuel, but it can completely cut sulphur emissions and reduce CO2 emissions by 20-25%. So, some leading energy companies have started to use these facts in order to promote natural gas as a short-term solution toward oil-free economy.

There are even some regulations that have been recently approved to favor LNG development. For example, the limits for sulphur content in marine fuels will be decreased from 1 % to 0.1 % from 1 January 2015 in Sulphur Emission Control Areas (SECAs) in the Baltic Sea, North Sea and English Channel. (It will concern about a half of 10000 ships currently engaged in intra-EU shipping). Sulphur limits will be also decreased from 3.5% to 0.5% globally from 1 January 2020. So, it will be required for ships to pass from heavy fuel oil to ultra-low sulphur marine gasoil or to LNG.

So, I think that on the way to oil-free transport, we will be obliged anyway to pass through intermediate semi-clean technologies favorable to oil companies.

Perhaps apollo era spacecrafts used fuel cells also for electricity generation. But today solar panels + batteries are superior.

Elon and SpaceX uses kerosene in launch vehicles and he has bashed hydrogen as a rocket fuel in other occasions. Elon thinks that methane is future of rocket fuel and SpaceX is already developing affordable methane rocket engine. Methane is cheaper than rocket grade kerosene.

He said that the both volumetric and joules per kg are worse even in the best case. So fuel cells will always be inferior even to today’s Model S batteries. And Battery tech certainly won’t stand still during the next few decades!

He bases his statement on the cost of building a hydrogen infrastructure along with EV batteries having higher energy density than hydrogen. I’m not sure if he’s saying that batteries contain more energy per kg or if placing a fuel cell between energy storage and the electric motor makes it essentially so.

Elon Musk Calls Hydrogen Fuel Cell Cars ‘Bullsh*t’
http://www.wired.com/autopia/2013/10/elon-musk-hydrogen/