In recent years, science and technology has progressed very rapidly and brought tremendous benefits to our lives. For instance, the development of transportation has dramatically extended the range of human activities, genome research makes personalized medicine possible, and the advancement of information and communications technology has minimized time and distance in communications.
Despite the fact that technology brings these lights, it also brought shadows. Advances in this matter have led to serious problems for humanity, such as climate change, ethical concerns in the biosciences, nuclear proliferation, and privacy and security issues in communication. Thus, it is essential to control the negative aspects on the one hand and develop the positive factors on the other. When we talk about science and technology, transportation and logistics is one of the largest industries that have been affected by these developments with both positive and negative ways. In last 50 years, developments in engineering and mechanics allowed us to build larger general cargo vessels, tankers and dry-bulk carriers.
Therefore, ship-owners and shipping companies have been able to take the advantage of ‘economy of scale’. This was a win-win game and since the economies of the countries have begun to intertwine with international trade, transportation and logistics became even more important. Consequently, none of the participants of this business was complaining.
However, at the beginning of the 21st century, the environmental effects of transportation have become a topic of increasing importance around the world. People started to realize that consequences of this ignorance could destroy our planet. Accordingly, some studies have been placed on this matter. Most recent ones show that in the seas surrounding Europe (the Baltic Sea, the North Sea, the North-Eastern part of the Atlantic, the Mediterranean and the Black Sea), sulphur dioxide (SO2) emissions from international shipping were estimated at 2.3 million tons a year, nitrogen dioxide ones at 3.3 million tones, and particulate matter (PM) at 250,000 tons. In a business as usual scenario, these emissions are estimated by the International Maritime Organization (IMO) to rise by up to 75 percent by 2020 if no action is taken.
Award-winning science writer Fred Pearce from Daily Mail UK says:”As ships get bigger, the pollution is getting worse. The most staggering statistic of all is that just 16 of the world’s largest ships can produce as much lung-clogging sulphur pollution as all the world’s cars.”
The problem is not just air and ocean pollution, studies show. An article from New Scientist Magazine takes the topic to a higher level. Catherine Brahic says:”Pollution from ships, in the form of tiny airborne particles, kills at least 60,000 people each year, says a new study. And unless action is taken quickly to address the problem – such as by switching to cleaner fuels – the death toll will climb, researchers warn.”
The good news is that it’s not impossible to prevent this harm to the environment. Technical measures to cut air pollution from ships by 80 to 90% are easily implementable. The benefits would considerably outweigh the costs involved. These include the adoption of cleaner fuels, adding ‘scrubbers’ or other exhaust gas cleaning devices to ships and wider use of alternative sources of energy.
For example, wind power has been used by ships as a means of propulsion for thousands of years, but with the advent of the steam and internal combustion engines during the Industrial Revolution the use of sail power fell away sharply from around the mid-19th century. Today however there is a resurgent interest in the use of sails for commercial vessels as shipping companies seeks ways to reduce fuel costs and comply with new airborne maritime mission standards. Traditional flexible sails with rigging are generally not suitable for large commercial ships, however rigid sails could be a practical way to utilize wind power on modern ocean-going vessels in order to lower fuel consumption & reduce noxious gas emissions.
Rigid sails are not a new concept and designs vary widely. In the 1970’s & 1980’s for example two ships in Japan were fitted with curved rigid sails and in the 1980’s Jacques Cousteau, Professor Lucien Malavard and Dr. Bertrand Charrier developed a turbo sail which was then fitted to the research ship ‘Alcyone’. Both of these innovative concepts reduced fuel consumption but for a variety of reasons, rigid sails have to date not gained widespread acceptance.
Another renewable energy technology suitable for ships is solar power. Over recent years significant advances have been made in terms of developing solar panels that are lightweight, more efficient and suitable for the harsh marine environment. Already a number of commercial ocean-going ships have been fitted with solar panels such as Nippon Yusen’s (NYK) Auriga Leader. At this stage solar power alone is unable to provide the energy required for propulsion on large ships; however it can be an important alternative source of power for on-board electrical systems thereby helping to reduce fuel consumption and noxious gas emissions.
The challenge for system designers is to develop a solution for ships that can tap into the power of the wind and sun – yet be cost effective, practical and not endanger the crew or vessel. Unlike land based renewable energy solutions such as solar or wind farms, the area or space available on ships for installing wind & solar power systems is quite limited. Taking this into account it would appear advantageous to develop a system that can use both wind and solar power as energy sources plus harness this energy via the same system.
Alternative energy systems are not intended to be a ship’s primary source of propulsion. Instead the systems are being designed to work alongside other technologies in order to reduce fuel consumption and harmful gas emissions for a variety of ships such as bulk carriers, oil tankers and cargo ships. Depending on the number, size, shape and configuration of the rigid sails it is estimated that these systems can reduce a vessel’s annual fuel consumption by up to 20%.
As a conclusion, the large scale use of modern renewable energy technology on ships is still in its infancy. As various technologies develop in the years ahead, we are likely to see the adoption of wind & solar power solutions in a variety of forms become widespread across the shipping sector.
The control, energy storage and power management systems for these solutions is sometimes over-looked but they will play a critical role in terms of making renewable energy a viable source of energy on-board the ships of the future.