Clarity Fuel Cell: Surprise Maintenance Costs

thinking out-loud (so-to-speak...)

From your gutters, you create a cistern,
Use your solar to separate H2 and O2,
Fill your tank (call it Hindenburg?) with H2, supply grandpa with the O2 that he needs,
Power your home fueling station with solar

Theoretically free H2 after initial investment? A possibility??

 

Magnitudes more efficient to use your solar to charge a battery.
Not only do you have to use electricity to separate the Hydrogen, you also have to use electricity to compress and cool it. The hydrogen tanks in cars are at 10,000 psi.

 

Also keep in mind

You forget that the batteries have to come from somewhere. Lithium from Chile, Cobalt from DRC, some metals from China, etc. Then you need two sets of batteries, one in your car, another in your home. With hydrogen you just make it and pump it when needed. Again it all depends on how much they succeed in reducing production costs and fuel cell cost. Besides as I mentioned before, the fuel cell can be a range extender, you won't need to use much hydrogen if you have a Clarity size battery.

 

Once you have the batteries, you can charge/discharge them thousands of times at no additional cost. And conceivably recycle them when they finally do reach end of life.

 

Not sure how that relates to "efficiency", but with the fuel cell setup, you have to account for the storage tanks, compressor, cooling system, etc.
And yes, all fuel cell cars have a battery to allow for regen and as a buffer for the fuel cell itself.
Most people will have grid tied solar and no additional batteries would be required. Fuel cells also have to come from somewhere and contain platinum, nickel, etc.

It takes 50+ kWh of electricity to make one kg of hydrogen. The Clarity FCX can travel 60 miles on that kg. That doesn't take into account the compression and cooling to get it into the vehicle.

 

Hydrogen fuel cell vehicles have the current problem that hydrogen is very expensive. But they have a few advantages over battery powered vehicles too. Hydrogen tanks can be filled as quickly as putting gas into a car. A hydrogen vehicle can have a range of 500 miles per fill up and still have a vehicle weight of 3500 to 4000 pounds. An electric vehicle with a 500 mile range would need over 2000 pounds of LI batteries, a larger suspension, more powerful motors, larger more expensive tires and could weigh as much as 6000+ pounds.
Technology in both areas are improving rapidly. If we can find a way to produce hydrogen for a lot less, fuel cell vehicles may be the future especially if battery technology fails to improve greatly. But if we can find a way to greatly reduce the size and weight of batteries and solve the charge time issue, battery vehicles could be the future.
I wouldn't want to bet on either one.