In the last few years, a quiet revolution has been taking place in the shipping industry. Shipping companies are beginning to transition toward fully renewable or cleaner energy sources to drive their vessels, and gradually giving up their use of fossil fuels. In an industry first, Finnish shipping firm Wartsila installed a hybrid energy system with solar power onboard the Paolo Topic bulk carrier in 2021.
Image Credit: Aun Photographer/Shutterstock.com
Need for Change in the Shipping Industry
Most of the goods traded between countries are transported on large container ships that require huge amounts of energy to get from Port A to Port B. By volume, around 80% of all world trade takes place between countries and across waters; 70% of world trade by value is carried by international shipping.
For the last couple of hundred years, these ships have been mostly powered by burning fossil fuels. Fuel combustion also typically provides power for auxiliary equipment such as heating and appliances.
As has become all too clear by now, this means of harnessing energy has a devastating impact on the health of the planet. Shipping accounts for 3.1% of the world’s annual carbon dioxide (CO2) emissions according to the latest research, plus 13% of sulfur oxide (SOx) emissions and 15% of nitrous oxide (NOx) emissions.
Recently, shipping companies have been trying to reduce the environmental damage caused by their industry by installing solar energy systems on merchant vessels. These systems bolster or even replace fossil fuel energy needed to drive the ships or heat their living and storage areas.
However, while inland solar energy is a relatively mature technology with wide-ranging applications, its marine use remains limited. Most solar installations in the marine industry supply static lighthouses and buoys, or battery charging for small sailing yachts.
With current technology, researchers estimate that solar energy investments for ships could take between 10 and 27 years to pay themselves back in reduced fuel costs, depending on solar radiation levels and fluctuations in fuel costs.
The Paolo Topic’s High-Tech Makeover
Wartsila, a leading shipping company based in Finland, announced its successful installation of a new hybrid energy system using solar power on a bulk carrier, the merchant vessel Paolo Topic. The company says that with this new installation the Paolo Topic is the most technologically advanced ship of its class to ever set sail.
Wartsila announced its plans to upgrade the Paolo Topic in 2019. The company completed the project in partnership with Marfin Management, the firm that operates the Paolo Topic, and leading solar panel manufacturer Solbian.
An energy management system optimizes the flow of power between an auxiliary battery bank and the ship’s electric grid. The system fits into a shipping container, making it ideal for use in the maritime industry. Wartsila said that it is suitable for tugs, ferries, coastal vessels, offshore vessels, and many more oceangoing deployments.
As well as the containerized design, the energy management system also benefits from specific application tuning, reduced maintenance costs, and increased energy efficiency onboard commercial vessels.
As a hybrid system, it can combine stored energy from batteries with dynamic energy sources such as solar power. The system already had supervisory control over the ship’s engines, batteries, and power distribution. Now, installing solar panels on the ship’s deck and including them in the energy management system represents a first for the maritime industry.
Solar Power in Shipping
Solar power is still a long way off being widely adopted in the shipping industry. Despite the allure of potential carbon-free international trade, marine solar power is still not a mature enough technology to make widespread adoption commercially viable.
Unlike static land- or even ocean-based solar panel installations, solar panels on ships must deal with unpredictable and dynamic conditions. These situations create new technical challenges for the mechanical systems that support solar panels and optimize their position for maximum energy capture.
For example, ships can change location very quickly – by up to a degree of latitude or longitude in one day. This means that the sun is at different points in the sky, so directing solar panels to point straight at the sun for maximum conversion efficiency is challenging.
The constantly changing location of a merchant's vessel also means that it moves between different prevailing weather conditions. This means that solar panels must be able to deal with quick changes in temperature and extreme conditions that would not generally occur in one location.
The unpredictable nature of the weather at sea is another factor that makes solar power in shipping such a difficult problem to tackle. Not only can clouds cover the sun, but storms and great swells can also appear quickly.
Even when the sea is relatively calm, the frequent pitching and rolling motion of a ship on gently swelling water constantly change any deck-fastened solar panels’ incidence angles to the sun, making them less effective at generating solar power.
Finally, while ships generally maintain a mostly straight line for much of their voyage, they are still capable of turning and often do. This also alters the incidence angle for any onboard solar panels, affecting their ability to generate power.
For solar power to completely replace fossil fuels in the shipping industry, these and many more unique challenges for moving, sea-based solar energy generation must be tackled.
References and Further Reading
Mircea, C. (2021). Bulk Carrier Gets a Unique Hybrid and Solar Energy System in a Maritime Industry First. Autoevolution.com. Available at: https://www.autoevolution.com/news/bulk-carrier-gets-a-unique-hybrid-and-solar-energy-system-in-a-maritime-industry-first-177147.html.
Visa, I., et al. (2016). Adaptability of solar energy conversion systems on ships. IOP Conference Series Materials Science and Engineering. Available at: http://dx.doi.org/10.1088/1757-899X/147/1/012070.