Hybrid ships that voyage across the deep blue could very well be the key to unlocking environmental sustainability.
The dream is alluring. A sleek ship on a sparkling sea, set against a sky of the purest blue, cleanliness and healthiness embodied in luxury. The reality is painfully different. Shipping is a major contributor to pollution and greenhouse gas emissions, responsible for an estimated 15 per cent of nitrogen oxide (NOx) and 8 per cent of sulfur gas emissions, said the Independentin February 2018. According to figures originally published in the Guardian in 2009, one giant container ship can emit almost the same amount of cancer- and asthma-causing chemicals as 50 million cars, and around 50,000 premature deaths in Europe have been attributed to international shipping.
To counteract the environmental and health impacts of ships’ air pollution, the International Maritime Agency (IMO) established Emission Control Areas (ECA) for waters around North America and Europe, in which sulfur standards for marine fuel are less than 0.1 per cent and, from 2020, a global 0.5 per cent sulfur limit in fuel will apply to all shipping.
Stricter emissions targets have encouraged ship owners to choose from a number of options including use of low-sulfur marine diesel, marine gas oil, ultra-low-sulfur heavy fuel oil and exhaust-cleaning devices such as scrubbers or alternative sources of energy including liquefied natural gas (LNG). But, for some ship owners, installing a hybrid propulsion system to existing or new vessels is seen as a rewarding way to meet emission targets.
In ECA waters and particularly around Norway, ferries, platform support vessels and cruise liners are pioneering the use of hybrid marine propulsion systems. Børre Gundersen, R&D manager for ABB’s marine activities in Norway, states that “hybrid propulsion systems significantly reduce both fuel consumption and emissions”. Gundersen’s colleague Sindre Sæter said: “Hybridisation of 230 offshore supply vessels operating in Norwegian waters could reduce CO2 emissions by 400,000 tonnes.”
Another attraction of hybrid marine engines is that they can be fuelled by diesel, LNG or hydrogen, and use a fuel cell, batteries or an electric motor. This capability makes hybrids particularly suitable for ferries in coastal or enclosed waters, explained DNV GL’s director of battery services and products, Narve Mjøs, who has seen increasing interest from cruise ferries between Portsmouth and Santander. UK shipbuilder Ferguson Marine has built Catriona, a £12.3m diesel-electric-battery-power hybrid ferry for CalMac to use on its Clyde and Hebridean routes. Also in the UK, Wightlink’s new flagship ferry for the Fishbourne-Portsmouth route will use diesel-electric hybrid batteries.
Hybrid systems are currently a niche segment worth just US$2,653.4m in 2015 but forecast to nearly double to $5,252.5m by 2024, according to Transparency Market Research report ‘Marine Hybrid Propulsion Market – Global Industry Analysis, Size, Share, Growth, Trends, and Forecast, 2016-2024’. Read more https://eandt.theiet.org/content/articles/2019/01/hybrid-ships-take-to-the-high-seas/