WHICH FUEL-CELL?

If you are going to buy a fuel-cell, or and FCV, or set your company on a course to use the technology, a PEMFC is the leading type, for very good reasons. Your first question when deciding which PEMFC to go with is 'What are its bipolar plates are made of?'

If the answer is 'graphite', stop talking to that supplier. Graphite plates will most definitely not win the day in fuel-cell technology. Any company making them or using them is going down a technological and financial cul-de-sac, flying into a commercial black hole.

If the answer is 'metal', carry on. Metal plates are cheaper, very much easier to mass-produce, tougher, easier to keep cool, etc. They beat graphite hands down.

Next determine efficiency, the efficiency of output, the efficiency of the cooling and humidification systems, the lifetime of the PEMs (proton-exchange membranes), the output in kW per litre, etc. Cost is the last consideration, and a comparatively minor one, because technical superiority will inevitably result in the best price. Even if the product were the most expensive at the start that disadvantage would not last.