Ammonia (NH₃) is a combustible gas that does not contain carbon (C), it can be used  in existing power generation facilities as a fuel which does not emit CO₂ when combusted.  

The combustion method which IHI is pioneering involves liquid ammonia being directly sprayed into the gas turbine combustor, which presents numerous advantages for social implementation, such as the simplification of the liquid ammonia fuel supply system from the storage tank to turbine, as well as improved controllability, while minimizing harmful emissions of nitrogen oxide.

Building the ammonia society and adding massive amounts of renewables to the global energy supply is not a matter of either/or, it is in fact a false dichotomy. Renewables and ammonia are complementary and will work in tandem for the energy transition, as “Green ammonia” creates a virtuous cycle of increasing the penetration of renewables. 
In actuality, "Green Ammonia" is a primary driver to drive untold additional renewable energy to the grid where it could not otherwise be managed. That is the whole point of renewably producing ammonia via hydrolysis in regions with surplus renewable energy potential, such as Saudi Arabia and Australia, enabling the "shipping of sunshine" to renewably poor Japan, the EU, etc.

This is not true—while we are pioneering the ammonia combustion with coal in a step-by-step fashion and have achieved a 20% ammonia mixture, the goal is to achieve 100% ammonia mono-firing. Thus, ammonia combustion with coal is an intermediate step, not a permanent condition, that realistically considers the deployment of blue and green ammonia supply infrastructure to meet the demand for ammonia in the power sector.

At a basic level, hydrogen and ammonia are both viable decarbonized fuel options. In most cases, ammonia is produced from hydrogen, resulting in an energy loss during conversion. Therefore, (gaseous) hydrogen has a cost advantage if it can be transported by pipeline. Ammonia is advantageous when used as an energy carrier to enable efficient, low-cost transport and storage of hydrogen. When transported by ship overseas, ammonia has a higher volumetric energy density than liquid hydrogen or organic hydrate, making it more efficient for transport and suitable for storage.

*In addition, direct combustion of ammonia offers lower energy loss and cost than decomposing ammonia to extract and use hydrogen, furthermore, has cost advantages over liquid hydrogen and organic hydrite. 

Ammonia is very safe if handled correctly according to well-established and regulated procedures. Ammonia is actually much less dangerous than many combustible energy sources due to its low flammability, as seen from the widespread use of ammonia-based fertilizers, household cleaning products, disinfectants, etc. - even as science experiments for children.
However, “ammonia” is instantly recognisable by its pungent smell and induces an immediate physical reaction in people, so the public will need to be convinced of its safety before it can be widely adopted in an ammonia society, and IHI understands the need to educate the general global public regarding the safety of ammonia when handled properly.

Regarding the broad ammonia society, there has already been positive engagement with EU peers in the industry and we would wish to engage further with partners in academia. For the European maritime sector, ammonia presents a great opportunity for European shippers as a hydrogen carrier, bunker fuel, and is readily applicable to shipping via the existing technologies possessed by LPG tankers. European academia already appreciates the potential of ammonia as a hydrogen carrier, and also its essential role as a fertilizer precursor in a European economy that faces massive disruptions in its traditional supplies of natural gas for ammonia synthesis.

Finally, establishing relations with public institutions such as ports and road authorities in the EU can help the ammonia society address regional regulatory conditions that are a key component of the larger global ammonia value chain.