Most of us when looking at the recent changes in the world’s climate are reasonably convinced that global warming is a reality. Whether this is solely a man-made phenomenon or not, most governments now recognise the need to reduce environmental pollution and particularly the emissions of carbon dioxide.
There can be few people in the developed world who have not heard of the potential of hydrogen as a clean fuel which used in fuel cells or burnt in internal combustion engines, would produce power with only water as a by-product. More correctly, since hydrogen has to be made rather than extracted from the earth, it would be an energy vector like electricity, rather than a fuel. In which case, what is wrong with electricity? The simple answer is that whilst electricity can be made in a variety of ways that would reduce pollution, it is very difficult to store in any large quantities and unless battery technology undergoes a step-change in energy density, it is not very portable.
Hydrogen has been viewed as having the potential to provide both a means of transmitting energy and of being both storable and transportable.
The modern story really starts in California in the late 1980’s when legislation was proposed to reduce pollution from urban transport against some key deadlines. Since then billions of dollars have been spent both by governments and private organisations to identify and test the best technological solutions. The driving force for much of the effort was not just the huge current energy demand, but the prospective demand as developing nations improved their standard of living. Few of us realise that over 1.6 billion people have no access to electricity and 2.6 billion have only biomass for heating and cooking. Projections, such as that by Shell above, look at how the energy need could be met, but do not comment on how the energy would be distributed. Many of the sources shown also have problems of seasonality or diurnal changes. The wind doesn’t blow all the time and even in deserts night falls on solar arrays.
... to continue reading you must be subscribed
