An ABB platform-to-ship frequency conversion solution is helping a floating storage and offloading vessel get electric power from a nearby oil and gas platform, eliminating the need to power ship systems with its own diesel engines. The resulting energy savings and displaced carbon emissions are considerable.
By ABB Communications
The solution is an innovative variation of ABB's pioneering shore-to-ship electric power connections that lets ships draw electricity from the quayside instead of using their own diesel generators while in port to generate electricity.
Installed in a floating storage and offloading vessel (FSO) called the N'Kossa II, the solution enables the vessel to power all its operations with electricity generated by gas turbines at 50 Hz from a nearby oil and gas production platform, and convert it to the 60 Hz frequency used onboard the N'Kossa II.
ABB's PCS100 SFC static frequency conveter shifts power to and from the 50 Hz and 60 Hz frequencies. Its uniquely high level of efficiency ensures maximum power availability, and its modular design and compact footprint provides a high and stable level of reliability.
N'Kossa II is a fully-refrigerated, liquefied petroleum gas (LPG) carrier operating in a fixed positon in the N'Kossa oil field, 50 kilometers off the coast of the Republic of the Congo in West Africa. Gas from the field is transferred from the production platform to the N'Kossa II for storage, before being offloaded onto other LPG carriers for transport to market.
The solution comprises two ABB state-of-the-art PCS100 SFC static frequency converters, as well as ABB medium voltage switchgear and transformers that are specially designed for the demanding 24/7 operating conditions of marine applications.
ABB supplied the world's first shore-to-ship alternative maritime power solution at the Swedish port of Gothenburg in 2000.
The PCS100 SFC uses the latest ABB power switching devices to provide clean, reliable and high efficiency power conversion from 50 Hz to 60 Hz or from 60 Hz to 50 Hz in industrial and marine applications. N'Kossa II requires around two megawatts of electricity to power its round-the-clock operations, power that was previously provided by the vessel's diesel generators at huge cost and high carbon impact.
Prior to that, an onboard and low-efficiency rotary converter provided the frequency conversion. The platform-to-ship solution was designed, installed and commissioned by ABB in October 2010, and has brought significant benefits to both the vessel's owner, Maersk FPSOs, and its operator, Total.
Maersk FPSOs has been able to equip this valuable asset with a cutting edge solution that provides safe, reliable and efficient energy for the vessel's operator; and Total is able to power the vessel at considerably lower cost and with significantly reduced emissions than previoiusly.
Built in 1992, and converted in 1994-6 into an FSO by Maersk FPSOS, N'Kossa II is a 49,000 ton liquefied petroleum gas carrier operating as a floating storage and offloading vessel in the N'Kossa oil and gas field off the Republic of the Congo coast.