Siem Offshore goes on battery shopping spree for three OSVs

All three battery retrofits will occur in Q1 2022 and follow the hybrid-battery upgrade of the dual-fuel LNG-powered Siem Symphony at Norway’s Westcon shipyard in Q2 2021.

Once the upgrades are completed on Siem Thiima and Siem Pride, all three of Siem’s LNG-powered PSVs will have battery-hybrid modules.

In the case of the subsea construction vessel, the Vard Electro double battery system with DC-link will allow the vessel to operate for one hour in fully electric mode, in addition to providing estimated fuel savings in excess of 20%.

The SeaQ ESS stores excess energy, either generated by the vessel or derived from shore connections with renewable power sources. This allows the use of battery power to drive propulsion and thruster systems, replacing engines running on fossil-based fuels.

Additionally, battery storage will be used as a spinning reserve in place of generator sets, enabling the vessel to run on fewer engines with better-optimised load while still maintaining the requirement for redundancy. An added benefit with batteries is peak shaving that takes the strain off the engines during big load variations by levelling the power and delaying the need for engines to restart.

This results in significantly lower fuel consumption and reduced maintenance costs due to less wear-and-tear on engines.

There are safety benefits with batteries as well, as Vard Electro head of commercial sales Gisle Anderssen pointed out.

“A significant benefit of battery storage is that it enhances the responsiveness of propulsion and other systems due to instant power response in line with load variations, offsetting slower ramp speeds with less responsive engines,” he noted.

This safety element is particularly useful for OSVs that are heavily dependent on DP systems for fast manoeuvrability in safety-critical situations, Mr Anderssen explained.

The batteries for Siem Offshore will be supplied together with a DC grid for power distribution to consumers, with control and monitoring of the battery storage solution handled by the SeaQ Energy Management System (EMS) that interacts with existing control systems onboard.

Mr Houge said “The flexibility of the SeaQ ESS system that enables it to be easily integrated with a vessel’s existing systems, as well as its advanced functionality, were key factors in our selection of Vard Electro for this retrofit to reduce our environmental footprint.”

Vard Electro will act as system integrator for the turnkey project that will entail engineering, installation, integration, testing, and commissioning of the system comprising batteries, DC grid, EMS, energy storage inverter, filter and/or transformer, fire detection, and a cooling and ventilation system.

Mr Anderssen said there is increasing demand for such hybrid retrofits both for offshore support vessels such as PSVs as well as larger ships.