Ammonia and hydrogen will be the main marine fuels if the world reaches net-zero in 2050, accounting for about 60% of the market together and with ammonia occupying the largest share, the International Energy Agency said May 18.
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Outlining its first road map for how the global energy sector can achieve net-zero emissions, the IEA said in such a scenario ammonia will account for 45% of energy demand from shipping.
Cost will be an issue. Small ammonia plants are expected to emerge worldwide beginning 2025, to produce green ammonia at $650-$850/mt ($34.95-$45.70/Gj), the Korean Register of Shipping, a not-for-profit ship classification society, said in a recent report.
After that, the cost is expected to drop to $400-$600/mt as larger plants are constructed in 2030 and then to further drop to $275-$450/mt in 2040, as consumption increases, favoring its use, it said.
By comparison, S&P Global Platts assessed delivered 0.5% fuel oil at Rotterdam at $484/mt May 17, equivalent to $11.10/Gj. Platts assessed methanol T2 FOB Rotterdam at $17.35/Gj.
Role of major ports
In any case, the supply of ammonia could be centered on major bunker ports, potentially at the expense of smaller ports.
"The 20 largest ports in the world account for more than half of global cargo [in the net-zero emissions scenario]; they could become industrial hubs to produce hydrogen and ammonia for use in both chemical and refining industries, as well as for refueling ships," the IEA said.
Internal combustion engines
Ammonia can be burnt in an internal combustion engine -- one of its advantages -- and such engines for ammonia‐fueled vessels are being developed by two of the largest manufacturers of maritime engines. They are expected to become available on the market by 2024, the agency said.
Pure hydrogen is unlikely to play a major role in any large-scale marine international transportation because of its lower energy density, S&P Global Platts Analytics said February in its Future Energy Outlooks: Annual Guidebook 2021.
Ammonia does better on the energy density front but still compares unfavorably to diesel, although newly built vessels might be able to accommodate this, Platts Analytics said.
Biofuels and electricity
Sustainable biofuels will provide almost 20% of total shipping energy needs in net-zero 2050, the IEA said.
Electricity would occupy only a very minor share as the relatively low energy density of batteries compared with liquid fuels makes it suitable only for short-sea routes of up to 200 km (124 miles). Even with an 85% increase in battery energy density as solid state batteries become commercially available, only short‐distance shipping routes could be electrified, the IEA said.
Net-zero in 2050 will be a tall order. The global rate of energy efficiency improvement also needs to ramp up to 4% per year through 2030 -- about three times the average over the last two decades, the IEA said.
Meeting the net-zero target requires total annual energy investment of $5 trillion by 2030, adding an extra 0.4 percentage point a year to global GDP growth, the agency said.