The practical fuel cell

A revolution in on board charging is on its way
Rarely is there wholescale revolution in our sport, but one admittedly fairly niche area where there is set to be considerable change is in the electrics systems on offshore race boats. Firstly there has been the advent of high efficency lithium-ion batteries as the modern day hi-tech replacement for conventional lead-acid ones. A substantial bank of these for example is being fitted to the new 182ft Eco-superyacht Ethereal, Ron Holland has designed for owner and co-founder of Sun Microsystems, Bill Joy. These will power not only the electrics but also the engine of this giant yacht. On race boats Li-Ion batteries are compact and lightweight and more robust than conventional batteries and retain no charging 'memory'. A more recent development is on the charging side, with the advent of fuel cells. These come with significant benefits over conventional diesel generators. For readers not up to speed with this Star Trek-sounding technology, a fuel is similar to a battery, except that where batteries are for the most part 'closed cell' (ie what's in there doesn't change until the cell runs 'out of juice'), a fuel cell requires a regular supply of fuel for its anode and 'oxidant' for its cathode - imagine a replenishing battery. While anode and cathode are constantly refuelled, a fuel cell also contains a fixed electrolyte just as a conventional battery has. We'll spare you the explanation of how fuel cells work at an electron level, except to say that they do work but in a slightly different way - they are more efficient the less current is applied to them. While typical lead-acid battery cells produce 1.5v, an individual fuel cell will produce 0.86v, and so like conventional batteries they tend to be clustered to output in the region of 30-50v. There are significant benefits of charging