From John O'Neill, Dunedin, New Zealand
In your look at Japan’s promotion of a hydrogen economy to coincide with the Olympics, you mention the Suiso Frontier bulk carrier vessel, which will ship liquid hydrogen from Australia to Japan (29 May, p 18). It will carry 1250 cubic metres of the stuff, although some will boil off en route.
To illustrate the downsides, if a heavier element was chosen as a power source instead of the lightest, the same amount of energy could be transported in 10 kilograms of uranium pellets, which would fit easily in a handbag. Australia has the world’s largest reserves of uranium, and Japan has around replaced by .
