Stealthy Spanish ethanol fuel cell submarine overbudget and behind schedule

In Spain, the highly advanced bioethanol fuel cell-powered S-80 submarines currently under construction in Cartagena now won’t likely be ready until 2022 and are expected to cost nearly $1.14 billion each after delays and overruns to the project doubled the costs and pushed the delivery date for the four vessels by nearly a decade. The vessels are also three meters too long for the docks where they’re being built. That said, the engines will be the most advanced in the global fleet with the vessels able to keep a constant speed of four knots underwater for four weeks without having to surface, compared to just a few days for diesel counterparts that must surface to let out air. The ethanol fuel cell engines will expel carbon dioxide-byproduct into the water via a special waste extractor that minimizes bubbles, increasing stealth capacity.