Batteries will be fundamental technology for reducing emissions and fuel consumption on tugs in ports if they are proven to be safe
They are already being deployed on tugboats worldwide in hybrid propulsion systems. Not all tugs will have an energy storage systems (ESS) as some have motors and generators to complement engine power. But as the price of battery technology decreases and pressure to lower emissions increases, battery installations on tugs will rise.
A few owners and port authorities already feel ESS costs are low enough to invest in electric-powered tugs. In New Zealand, the Ports of Auckland will receive fully electric ship-handling tug Sparky from Damen Shipyards soon.
This tugboat was launched at Damen’s Song Cam Shipyard in Vietnam in Q4 2020 and is the first to use Swedish company Echandia’s lithium titanate oxide (LTO) battery in a marine environment. Bureau Veritas approved LTO technology for maritime use in May. Echandia founder and chief executive Magnus Eriksson said, “It is a breakthrough for safe LTO technology as tugboats increasingly become battery-powered.” Echandia also has type-approval for its E-LTO system from DNV.
Class society approval is essential for deploying ESS units on tugs, but so is ongoing safety testing to ensure they do not start fires or create infernos. Positioning and designing batteries for safe hybrid or all-electric propulsion are equally important.
Boluda Towage Europe chief executive Geert Vandecappelle explained the challenges of batteries and hybrid propulsion during Riviera Maritime Media’s How tug operators are preparing for a new era in green marine propulsion webinar.
Mr Vandecappelle said there were operational and safety issues with the first hybrid propulsion tug which needed rectifying in the second generation of tugs. A key issue on Rotortug RT Adriaan (now named VB Kracht) was the high temperature battery packs created in the enclosed space. Boluda fixed this issue by splitting ESS units into different rooms on tugs RT Evolution and RT Emotion, said Mr Vandecappelle.
The lessons naval architects have learned from battery deployments on tugs will hopefully prevent fires in the future. But as has been seen in the ferry sector, battery fires can devastate vessels.
Placing ESS units in dedicated battery rooms is a key safety feature, but costly when designing new tugs where underdeck space is scarce. Sterling PlanB thinks it has a solution. It tested a battery module in extreme temperatures, demonstrating it could withstand an A60 test with a 950°C fire, as its internal thermal management and liquid cooling system continued operating.
These tests simulated a fire breaking out in the machinery space adjacent to the lithium ESS, examining the potential for batteries to contribute to the intensity of an existing fire.
With that test successfully passed, and tests completed by other battery manufacturers, tug owners can deploy ESS units with greater confidence in their safety to reduce emissions from port operations.
Therefore, the future looks very bright and safe for electric-powered tugs and operators looking to eliminate their emissions.
Riviera Maritime Media’s Maritime Hybrid, Electric and Fuel Cells Webinar Week is being held 22 June 2021 – use this link for more details and to register