Unfortunately ammonia is about 82% nitrogen, which adds nothing energy-wise, so we're looking at storing, transporting, etc. a product that's only 20% useful from an energy viewpoint... most novel ideas run up against basic physical and chemical laws when you involve change of state (liquefaction,compression,etc.) due to the energy costs of transitional operations, on top of any chemical changes as well. If you wanted to be really green you could use ammonia as fertilizer to produce biomass as renewable fuel for your thermal power plant and claim all sorts of green credits from the government for the energy produced.(See British power from Canadian and U.S.woodchips).
