The maritime industry is one with a long and rich history. It has been around for centuries, and the industry is still continuing to grow and progress in many areas, one of which is advancements in marine propulsion system technologies to enable cleaner and greener operations.
This sustainable development of the maritime industry is also known as marine electrification, a term that has been actively debated and discussed within the industry for many years as a result of the industry’s impact on the environment and climate change. Although much has been done to minimise the maritime industry’s carbon footprint, it does not appear to be sufficient, and more businesses should join in on the green initiatives.
1.0 AN OVERVIEW OF THE MARITIME INDUSTRY
1.1 A Dive Into the Growth of the Maritime Industry
Maritime refers to anything that has to do with the sea or the waterways that connect us to the rest of the world. It encompasses not just the shipping of consumer goods but also navigation, marine engineering, and even military activity. It is an integral part of living in modern-day today, particularly in Singapore, where the majority of the items we use on a daily basis are imported and directly impacted by the industry.
Travelling by sea has long been a key mode of transportation; in ancient times and the few centuries after that, it was even the only form of transport around the world, serving as the only connection between countries.
The first ‘ships’ ever invented were known to be single logs that floated down rivers for trade. Only small cargo could be attached to them then. Eventually, these single logs became bigger boats where they were made by tying many logs together, allowing people to carry a lot more items with them.
These trading routes then evolved from short trips down the river to longer distances during the Chalcolithic Period, when countries in Southeast Asia, Western Asia, the Mediterranean, China, and the Indian subcontinent formed major trading routes by sea. This is around the time when the maritime business started to grow.
1.2 Evolution of Marine Propulsion Systems
Marine propulsion systems, as we all know, are the mechanisms or technology utilized to generate thrust in order to push and move a vessel or boat over water. Manpower, in the form of paddles and sails, was the initial type of marine propulsion. Many rowed galleys with sails were also an important feature of the early marine propulsion system.
While some smaller boats today still use paddles and sails, most modern ships are propelled by mechanical systems that include an electric motor or engine turning a propeller or operating a thruster.
The marine steam engine, which was introduced in the early nineteenth century, was the first advanced mechanical marine propulsion system invented. It was used in conjunction with paddle-wheel propulsion and coal-fired steam.
Prior to the application of coal-fired steam engines to ships in the nineteenth century, oars or the wind were the primary forms of watercraft propulsion. However, coal-fired steam engines are no longer a commodity and have even been criticised for their coal pollution and detrimental impact on the environment.
Combustion engines and diesel engines were then invented in 1876 and 1892 respectively, with diesel engines being used a lot more commonly in replacement of steamships following World War II because many steamships were destroyed during the war and diesel engines were considered a lot more economical.
The Liquefied Natural Gas (LNG) ships were then developed, it is nearly sulphur-free and can significantly reduce particulates and harmful emissions. These solutions were, however, still not the most environmentally friendly.
In 2008, due to stringent environmental regulations and rising fuel prices, the maritime industry had to turn to wind and sun for their propulsion solutions. This was when the first solar-powered ship was launched, followed by many other ‘green shipping’ efforts.
Fast forward to today, the advances in technology have given way to many more marine propulsion systems that offer greater benefits to the maritime industry and our environment. Especially with the increased emphasis on sustainable practices and the rise in green consumerism amongst consumers, the industry will need to continue evolving and developing new and cleaner technologies to protect our environment and reduce their impact on global climate change.
1.3 Maritime Industry’s Impact on the Environment and Climate Change
The maritime industry is the primary driver of global trade, transporting approximately 80 to 90 per cent of all goods by sea, amounting to more than 10 billion tons of containers, solid, and liquid bulk cargo transported annually across the world’s seas.
In 2018, more than 90,000 ships travelled the oceans, burning nearly 2 billion barrels of fuel while transporting oil, gas, chemicals, metals and other goods. This figure is anticipated to climb even further as online shopping from global platforms and international shipping becomes more popular.
The maritime industry, particularly shipping, has a tremendous impact on our global economy, generating billions of dollars in revenue each year. However, it is also one of the world’s most polluting industries, contributing greatly to air, water, oil and noise pollution.
Ships account for around 18 percent of some air pollutants, including 18 to 30 percent of nitrogen oxide and 9 percent of sulphur oxides. These emissions are generated by diesel engines that burn fuel oil with high sulphur content, also known as bunker oil, producing sulphur dioxide, nitrogen oxides and particulate matter.
On top of that, these emissions also include pollutants such as carbon monoxide and hydrocarbons, which lead to the formation of aerosols and secondary chemical reactions. They have been recognised by the EPA to contribute to ozone and carbon monoxide nonattainment (failure to meet air quality standards) and adverse health effects endangering human health, especially along key shipping routes.
High sulphur content in the air creates acid rain which will damage crops and buildings. When inhaled, it is also known to cause respiratory problems and even increases one’s risk of a heart attack.
The industry also creates between 3.5 per cent and 4 percent of the world’s total greenhouse gas emissions, primarily carbon dioxide, contributing substantially to global warming and climate change.
The International Maritime Organization (IMO) then adopted new sulphur limitation regulations in 2016 which came into force on 1st January 2020. This marked a big step towards improving air quality, preserving the environment and protecting human health.
This regulation, also known as “IMO 2020”, limits the sulphur content of fuel oil used on board ships operating outside designated emission control areas to 0.50 percent mass by mass, a significant decrease from the previous limit of 3.5 per cent. Limits within designated emission control areas were already stricter, at 0.10 per cent.
In order to meet the new regulations and lower their impact on the environment, businesses began adopting marine electrification efforts.
2.0 MARINE ELECTRIFICATION
2.1 What is Marine Electrification
As the world’s industries shift toward more environmentally friendly operations, the maritime industry has also been encouraged to cut its greenhouse gas emissions by half and adopt green practices to lessen its negative impact on the environment.
However, in the world of sea transportation, energy comes from predominantly petroleum-based sources of fossil fuels, which pose a significant environmental challenge. To push for marine electrification, the new regulations force the sector to explore sustainable energy, batteries, and additional energy storage technologies.
Marine electrification is a generic term that refers to the transition of the maritime industry from the use of fossil fuels to the use of electricity for operational needs. It covers the entire boat propulsion system, which includes everything from the generators to the propellers and thrusters.
Electrical marine propulsion systems provide numerous benefits to our world and to the operators in the industry. Switching to cleaner energy and implementing sustainable practices can be far more beneficial than burning fossil fuels, from enjoying cost savings to improved operational efficiency.
2.2 Electrical Marine Propulsion Systems
Before the development of electrical boat propulsion systems, there were many other propulsion systems such as diesel, wind, gas turbine, fuel cell and even nuclear propulsion systems. Some of them are a lot more cost-efficient and eco-friendly compared to the rest, others offer a variety of other benefits. However, with electrical propulsion options, the benefits you get far exceed fuel consumption cost savings and energy efficiency. Marine electrification has made it possible to explore a plethora of new propulsion systems, take a look at some of the environmentally friendly propulsion systems below.
2.2.1 Hybrid Marine Propulsion System
Unlike the conventional propulsion systems, where there is only one source of propulsion or power, the hybrid marine propulsion system actually combines two or more sources of propulsion into a single design; diesel electric, battery, etc.
When operating a boat running on hybrid propulsion, it can either be powered solely by the diesel electric, battery, or both simultaneously. This provides the boat with a wide range of operational capabilities.
From reducing your company’s carbon footprint and contributing to climate change prevention to other advantages such as comfort onboard and economic savings, switching to a hybrid marine propulsion system presents an array of benefits to your company. Some of the other benefits include a quieter, vibration-free and emission-free operating system and lower fuel consumption while experiencing higher power output levels, and better performance.
2.2.2 Battery-Powered Ship Propulsion
As the name suggests, the battery-powered ship propulsion system is a fully electric system that consists of an electric motor powered by a battery pack.
Some of the benefits of the battery-powered ship propulsion system include a zero-emission operation, reduced noise pollution, no fuel consumption, and lower maintenance costs. The low noise and vibration levels on board also provide all crew and passengers with a higher level of comfort.
2.2.3 Diesel-Electric Marine Propulsion System
The diesel-electric drive was initially introduced in the early 1900s and has been around for over a century, with considerable improvements in recent years. It is a rising technology that consists of several gensets used to power vessels and boats.
The diesel-electric drive is an extremely efficient system in which one or more diesel gen-sets can power several electric thrusters at the same time. This is possible because the diesel gen-sets are only activated when needed, based on the load requirements of the boat; they will even start and stop automatically depending on the load demand.
A single diesel genset can even be used to power multiple devices at the same time, such as the main propulsion, bow thrusters, hotel electrical load and pumps. This eliminates the need for many engines to be running concurrently just to power various devices on the vessel.
Unlike conventional propulsion systems, where energy is transferred via a long shaft, the diesel-electric propulsion system transfers energy via cables, which makes it versatile and employable in boats of varying sizes. Their flexibility allows them to be situated in various spots within the boat, allowing for better distribution of all equipment and mechanical systems.
The diesel-electric drive is also capable of tailoring electrical power outputs to the changing needs of the boat’s systems, helping you to save costs and reduce fuel consumption. As a result, your electrical system’s overall performance improves and becomes more optimal.
With optimal performance and more energy efficiency, the diesel-electric marine propulsion system will consume far less diesel fuel and emit fewer pollutants into the atmosphere.
Furthermore, the diesel-electric propulsion system is much quieter in operation, delivering a significantly more comfortable voyage for both passengers and crew on board.