Political cost?
I doubt it. If this process is scalable and inexpensive, people & companies with a lot of $$, including oil and coal companies, will jump on it to be in on the ground floor. Those people that run the energy business aren't fools, and if this process produces hydrogen cheaply & plentifully, they'll be all over it. A cheap hydrogen source could also be used with CO2 from the atmosphere to make liquid fuels like diesel and gasoline, making these into a renewable resource.