Classification society DNV GL and French oil major Total have initiated a joint industry project (JIP) in cooperation with several industry partners to explore how hybridization in tanker shipping and, specifically, auxiliary engines on small tankers, can reduce operational costs and improve environmental performance.
Other partners include ship designer FKAB Marine Design, battery manufacturer SAFT Batteries, shipowner Viken Shipping, and ship operator Wallem Shipmanagement.
The JIP is focused on the long-term benefits of lithium-ion battery systems for auxiliary power management onboard smaller-sized oil or product tankers in the 17,000 dwt range. Reference data, such as trading patterns, typical modes of operation, and power loads were aggregated from conventional sister vessels, DNV GL explained in its May issue of DNV GL Tanker Update 2018.
Additionally, the project looked at potential benefits of batteries when used for various purposes:
- to boost the available supply of power at times of maximum demand, or in case of machinery failure (spinning reserve)
- to avoid loading down the generator sets excessively, which causes high fuel consumption (peak shaving)
- to achieve a more even loading of the generators (load levelling)
- to allow the generators to run at the most economical load levels and reduce the number of generator sets required on board
- to feed on-demand power to equipment as needed (such as discharge pumps, tank cleaning equipment and thrusters during port navigation)
- to provide propulsion power at very low transit speeds (in port) as well as in high-sea emergency operation
Based on the power needs of the reference ships, the required battery size when eliminating one generator set was calculated to be 400 kWh.
Over a 20-year operating period, all hybrid configurations investigated performed better than the conventional base scenario. It is thus safe to say that hybridisation of the auxiliary machinery is beneficial, at least for smaller tankers, and should be considered in all newbuilding projects. The required battery package size should be determined based on the ship’s power needs,
…said DNV GL expert Ole Vidar Nilsen.
