Danish researchers at the Technical University of Denmark may have taken an important step towards hydrogen based transport systems. In a news article they say that they store the hydrogen as ammonia absorbed in sea-salt tablets [cached]. “Within the tablet, hydrogen is stored as long as desired, and when hydrogen is needed, ammonia is released through a catalyst that decomposes it back to free hydrogen. When the tablet is empty, you merely give it a “shot” of ammonia and it is ready for use again.” They are working on commercializing the technology, and they claim to already meet the US DOE 2015 goals for volume and energy density. What is particularly interesting here is that one of the possible outputs from an OTEC plant is just that, ammonia (PDF). And ammonia is easy to transport in comparison to hydrogen. The question is whether this method of producing ammonia from solar energy will be economically competitive or not.