Hydrogen - Economically Unviable?

I have been reading a book that I referred to in an earlier post called "The Hype About Hydrogen" by Joseph Romm.he examines the case for switching to hydrogen as the energy carrier for the future.  Romm worked in the US Department of Energy between 1993 and 1998.  From mid 1995 he held the number 2 spot in the office of Energy Efficiency and Renewable Energy.  He is well qualified to explain the facts and issues surrounding a potential future hydrogen economy - and there are many.  The book is heavily focused on the US, although he does look at Iceland as a place where a hydrogen economy may be viable, primarily because they have excess geo-thermal energy that can be used for the generation of hydrogen.

Romm is convinced that man-made global warming is a real threat.  He is equally convinced that there will not be a viable hydrogen based economy for some decades.  There are many technical and economic problems to be overcome, which makes current US policy look distinctly flawed.

He primarily investigates the issues surrounding fuel cells.  These are devices that take hydrogen in one end (or a substance from which hydrogen can be released), air (providing oxygen) in the other and generate electricity and water.  On the face of it clean energy.

Fuel cells are not a new idea - they've been around since the 19th century, but they've never made it into mainstream production, primarily because of the cost and technical issues associated with them.

There are different types of fuel cell - some operate at low temperature, but require to be fed from an external source of hydrogen.  These tend to be expensive because they need platinum catalysts.  Others operate at high temperature.  They can form their own hydrogen from sources such as natural gas - but they take a while to get up to temperature.

There are all sorts of challenges to overcome if a hydrogen based economy is going to be viable.  Generation of hydrogen - if the goal is to get off fossil fuels because of the related greenhouse gas emissions, then the CO2 released as a by-product from reforming natural gas needs to be captured and sequestered.  If the electrolysis of water is to be used as a source then we need a lot more electrical energy than we currently produce.  Another problem is transportation.  The energy density of hydrogen per litre is only a third that of petrol - so moving it around using hydrogen is not very efficient.  It takes up a lot more space than the equivalent energy volume so requires bigger tanks.  It damages pipes that are used to carry it.  Being a very small molecule it leaks.  There are other health and safety issues that need resolved - for example if it does catch fire it burns with a clear flame making it impossible to see.

Stationary high temperature fuel cells seem to be a potentially viable option for buildings - but the energy and potential CO2 emissions required to generate the hydrogen need to be taken into consideration.  If not using renewable energy sources - which are currently in relatively short supply - then fuel cells are generally not more efficient than burning the natural gas in a power station - and a lot more expensive to make.

The bottom line is that there is no set of easy solutions to these problems.  Much more research and investment is needed to overcome them.  In the meantime, plug in hybrid vehicles and other forms of renewable energy being developed in Europe and elsewhere will rule the roost for some years to come.  Romm's plea is for the US government to change its policy and invest more in other forms of energy generation.  He doesn't advocate abandoning hydrogen - but suggests it should be seen as a longer term option.

This is an informative book.  It presents the numbers and the sources of information used.  It's not the easiest of reads - but I'd recommend it for those wanting to be better informed about the subject.