The concept of adding liquefaction capacity to a Moss LNG carrier by a mid-ship extension can also be adapted to add power generation to create a combined FSRU/Power Ship. FSRU’s are commonly used to supply gas for onshore electrical power plants. For markets that need both LNG import/storage infrastructure as well as new gas fired power generating capacity or an expansion of capacity, the FSRU/Power Ship can be an ideal solution. The power vessel can be assembled in a shipyard and brought to site as a completed unit, ready for production, thus saving time over a conventional, “stick built” onshore plant.
The liquefaction vessel mid-ship section normally has 72 MW of installed power. However, up to 300 MW of power can be incorporated into the mid-ship section using either medium speed 4 stroke engines or slow speed 2 stroke engines. Efficiencies of 49% (6963 BTU/kW-hr) can be achieved with neat engines or up to 53% (6438 BTU/kW-hr) with auxiliary waste heat steam added.
For smaller, island markets in areas subject to hurricanes or cyclones, a self-elevating jack-up type platform can be used instead of a ship. The jack-up would be installed in 12 – 20 m WD to allow refueling by an LNG ship and elevates itself above the water sufficient to clear any storm surge or waves. Typical power capacity would be 50 – 150 MW with medium speed engines in the hull and Type C independent LNG tanks on deck. Like the power ship, the jack-up power plant would be completely assembled in shipyard and transported to location by dry tow vessel for installation. It offers a clean burning, high efficiency portable and relocatable solution for small, isolated markets.