So for the last 5 years the Iowa Energy Center at Iowa State University has been holding annual conferences on the use of ammonia as a fuel, and some of that dreaming is now coming out of the lab.
The chemical formula for ammonia is NH3. Combined with CO2 you know it as urea, the main component in urine. There are patents on producing anhydrous ammonia (the kind useful as fuel) from urea but currently the main feedstock for it is natural gas. Ammonia produced in this way is called "brown ammonia."
The most recent Iowa State ammonia conference was held in Kansas City, and featured demonstrations of a car running on ammonia, and explanations of ammonia as a direct fuel (replacing hydrogen) for fuel cells, as well as many sessions on storing and transporting it.
Wizard Power in Australia has demonstrated a closed loop energy system. In this system solar energy converts hydrogen and nitrogen gas to ammonia, the ammonia is a feedstock for energy production, and nothing gets out.
A hydrogen energy cycle solves many of the problems we have with carbon energy, and with water as the "pollution" it can help solve the world's water shortages. Ammonia has all these advantages, plus it can deal with agricultural pollution. And it's more cost-efficient.
That's why SunBorne Energy of India is funding research at the University of South Florida that hopes to use ammonia to cut the costs of solar energy by half, and produce energy at lower temperatures.
But note that connection with urea again. A coal-fired power plant in Wisconsin is testing the use of chilled ammonia to extract carbon directly, which could make clean coal a reality.
So hydrogen is smart energy. It bypasses the carbon cycle and gives us water as a by-product. But ammonia is smarter, because it is more energy dense, it is readily transported, and because it connects with carbon in the same way your own bladder does.