Martin Cartwright, Global Business Director Gas Carriers & FSRUs at DNV, explains why the over fifty very large ammonia carriers (VLACs) that have been ordered recently, will, most likely, initially operate as LPG carriers.
Surge in newbuild costs changes the dynamic
According to Martin Cartwright, the price of constructing a 93,000 cbm LPG carrier has risen to around USD 125 million in 2024, a significant increase on a price of around USD 75 million in 2020. Making amendments to these LPG carriers so that they are capable of carrying ammonia adds between USD 1 million and USD 1.5 million to the cost. With this accounting for around 1% of overall costs, it makes sense for shipowners to make this investment and secure transportation flexibility for the next 15 years. This has also been a huge factor in the almost even split between dedicated VLGCs and multipurpose VLACs contracted this year.
From LPG carriers to ammonia carriers
Most of these new VLACs are expected to initially trade as regular LPG carriers in the earlier years of their existence, particularly as large-scale supply chains for ammonia are still some years away from development. Nonetheless, making this extra investment means that shipowners will be in a position to serve the ammonia market when the time comes.
Owners ordering very large ammonia carriers today will be serving the burgeoning LPG market in the short term before switching their vessels to ammonia cargo in the future.
Whilst there are currently many VLACs in the orderbook (or VLGCs capable of carrying ammonia), these vessels are not yet fully optimized for carrying ammonia as their core cargo. These vessels will be sufficient to absorb higher volumes of ammonia when the market initially gets to this point, but they are still primarily constructed – and optimized – with LPG in mind. In the longer term, we are likely to see a reversal of the trend. New trade routes, different charterer requirements and higher traded volumes of ammonia are likely to lead to growth in the number of vessels constructed as VLACs primarily for ammonia transportation are optimized for this purpose, Martin Cartwright explains.
Design changes required for ammonia transportation
Equipping these vessels to be primarily capable of carrying ammonia requires design changes focusing on some key differentiators.
Cargo capacity is one of the main considerations. The different properties of LPG and ammonia mean that the filling limits of tanks will vary. LPG has a lower specific gravity – 0.61 compared to 0.68 for ammonia – whilst the different thermal expansions of the two substances also differ. When tanks are designed for the lower density of LPG, filling volumes have to be reduced when transporting ammonia. However, according Martin Cartwright, making design adjustments to the tank to allow for the gravity and density of ammonia will make filling ratios the same for both products.
Healthy market ahead as LPG and ammonia demand set to increase
Looking ahead, seaborne trade is expected to continue to grow for LPG/ammonia carriers. LPG demand is on the rise from China, India and South Korea, whilst the global trade of low-carbon ammonia is expected to grow on average by around 4% per year, reaching around 69 million tonnes by 2040.
In the short term, this surge will mainly be handled by medium gas carriers (MGCs) and this remains one of the most dynamic spaces to watch in 2024. However, when larger volumes of green and blue ammonia begin to hit the market in five to ten years’ time, VLACs will become much more relevant with the switch from LPG to ammonia as the main transportation cargo, Martin Cartwright concludes.
