Industry collaboration, incentivisation and guarantees to help protect bold investments, with clear policy direction, are needed for the energy transition to be successful, writes Malin Group principal naval architect Chris Dunn
The quest for vessel operations to be more energy efficient officially began in April 2018, when IMO announced its strategy to reduce greenhouse gas (GHG) emissions from ships.
This strategy set out ambitious goals of reducing CO2 emissions by 70% by 2050, with the target of phasing out GHG emissions from international shipping as soon as possible, during this century.
While several drivers are pushing forward the need for this energy transition, the most prevalent is climate change; natural disasters such as the catastrophic bushfires in Australia in 2020 burned through 10M hectares of land following the country’s hottest and driest year on record.
In 2019, the marine sector was responsible for 90% of world trade; it represents a lifeline industry but also impacts on our quality of life. Indeed, shipping is notorious as a leading contributor to GHG production and as the IMO has outlined, this must change.
The shipping industry must be transformed to meet the targets being set, with the implementation of reduced emissions technologies – adapting and improving vessel designs and ultimately replacing fleets with zero-emission ships.
Transportation response to climate change
To meet IMO targets, vessels running on clean alternatives must be operational well before 2030. If IMO legislation continues to tighten, we could see current vessels forced to retrofit green propulsion technologies to avoid being outlawed within the next few years.
As we look ahead, I predict the main players through the early stages of the energy transition will be batteries, hydrogen, and synthetic ammonia, made with green hydrogen – all of which are technologies currently being heavily researched and explored across the world.
“To meet IMO targets, vessels running on clean alternatives must be operational well before 2030”
Batteries, while readily available, are currently only suitable for a small range of vessels. Their suitability is restricted owing to their heavy weight and the requirement for charging infrastructure at all, or at least a subset, of ports.
Hydrogen can be readily produced, stored, and distributed without as much invasive port infrastructure demand. However, hydrogen takes up a large amount of space, and the associated volume requirements on board currently makes it a viable option only for smaller domestic vessels that travel known routes and return to the same ports regularly to refuel. These volume constraints will be the biggest limiter on the adoption of compressed hydrogen systems, although research into methods of carrying more energy in an equivalent volume, for example using liquid hydrogen and liquid organic hydrogen carriers (LOHCs), is advancing rapidly and these could resolve some of the issues.
Synthetic ammonia, which has almost double the energy of compressed hydrogen by weight and exists in liquid form at only 10 bar, is much easier to handle and store. Although toxic to humans and 75% more expensive than the hydrogen used to synthesise it, ammonia’s enhanced power density will offer significant advantages over hydrogen for larger ships on longer journeys.
There is a growing movement which heralds hydrogen as the best potential short-term solution; specifically, green hydrogen, produced from the electrolysis of water using renewable power.
To break this down, if you take nine tonnes of fresh water and between 50 and 55 MW hours of clean electricity generated through renewables, and combine this in an electrolyser, you will obtain a tonne of (green) hydrogen and eight tonnes of oxygen. The hydrogen created can then be compressed and stored for long periods of time, with the only limit being the availability of storage space. This can be distributed via pipes or on vehicles. Then, when you are ready, you can put it back into a fuel cell along with fresh air and you will get 23 MW hours of clean electricity – to do with what you like, in this case to propel a boat.
Today, the end-to-end process has an efficiency of between 35% and 40%, but this is consistently improving as technology advances. Given this, one may ask, what is not to like, particularly if it uses waste electricity? Indeed, why aren’t we doing this with all of our constrained energy? Well, we have started.
Some would argue green hydrogen “is too expensive” and “it can’t compete with diesel”. Such arguments are valid at the moment, with diesel cheap and technology expensive. However, this is a short-term issue, and it is changing quickly.
“Shipping is notorious as a leading contributor to GHG production and as the IMO has outlined, this must change
A comprehensive Australian report published in 2017 vastly underestimated the speed and scale of deployment of electrolysis and related technology developments, stating that the cost of green hydrogen would not be cost competitive with blue hydrogen until 2050. Everything has changed since then, with a huge research effort.
For example, Chinese manufacturers have reported making systems that can create hydrogen with renewable energy for up to 80% less than the Australian report predicted three years ago. The price of an electrolyser today is approximately US$800 per kW, and the US Department of Energy predicts that this will drop to US$200 by 2040. But in India, entrepreneurs are already promising electrolysers at US$550 and India’s forecasting to generate green hydrogen at US$1 per kW in the next couple of years – blowing all previous projections out of the water.
The renewable prospects are fantastic, but we are stuck in a brutal supply and demand trap. There will be no convincing business case to justify making hydrogen available at this scale until there is sufficient demand for it. And similarly, few are prepared to invest in a hydrogen-fuelled machine when there is no guarantee of hydrogen supply, let alone a price promise.
The energy transition is not likely to happen without the alignment of three crucial factors, namely: joined up industry collaboration; incentivisation and guarantees to help protect the bold investments; and a clear statement of direction from the legislators and regulators. The first goal is therefore to raise awareness, doing all we can, collectively, to lobby, discuss, debate, and demonstrate the need to tackle this issue, in as many forums as we can – we need to add pressure to the decision makers until the issue can no longer be ignored.
The next step is innovation – but not just through meetings and drawing things on screens; instead, we need to move our myriad of ideas to expertly engineered proposals, which are then utilised to deliver demonstrator projects of all shapes and sizes. Some will work, some will not, but this didactic approach will add momentum to the movement, helping to produce more effective technologies, combined with a demand that will stimulate electrolyser installation. In turn, this will create some resilience in the hydrogen supply and hopefully market forces will take it from there.
The challenge presented to us is of an unprecedented scale, but also one that offers unrivalled opportunities to influence change and have an impact. It is increasingly being addressed across the world – and we must continue to play our part, as we together embark on this green revolution of recovery.