Fuel cell systems are already much more efficient than internal combustion engines with the latest designs getting upwards of fifty percent. That puts them at about double what a good gasoline engine gets. However fifty percent still leaves a lot of room for improvement. Swedish company Group Opcon AB has a subsidiary called SRM that focuses on renewable energy. Hydrogen is passed through a fuel cell stack where it reacts with oxygen in an electro-chemical process that produces electricity and water. As might be expected, not all the hydrogen reacts, so SRM is developing a new compressor that recirculates the hydrogen back through the stack to react again. This should help raise the overall efficiency of the stack system and increase the range while allowing for size and weight reductions.