Global adoption of small-scale liquefied natural gas (LNG) could be a reality soon thanks to Wärtsilä’s LNG floating storage and regasification barges (FSRBs). They facilitate access to tricky locations that were once impossible to reach to deliver, store and distribute LNG.
While small-scale LNG has the potential to help solve many of the energy challenges faced by developing countries, complex, off-the-grid locations, lack of infrastructure and the absence of small-scale terminals for delivery, storage, and redistribution are the main obstacles to its more widespread acceptance. However, as the capacity to supply LNG around the globe continues to grow, with larger LNG supplies coming from Australia, as well as from the United States, both international oil majors and state-owned oil companies are looking for innovative ways to make LNG available for small-scale applications.
The global LNG infrastructure of today consists of large land-based terminals and floating storage and regasification units (FSRUs), which store the LNG and send out gas to large national pipeline networks. This format will not work for more
remote areas which are not served by pipelines, nor for those, such as islands in Indonesia or the Caribbean, where any pipeline grid will have to be small scale. Small- and medium-scale LNG infrastructure is the optimal solution to supply
energy to such remote or isolated regions.
Even though LNG is often the most cost competitive energy source in these tricky circumstances, some locations are simply not suitable for establishing an LNG terminal. This may be due to remoteness, a lack of available land, high cost of building, or insufficient infrastructure to support the building of a terminal.
In situations such as these, an FSRB is that crucial piece in the LNG puzzle that has previously not been available as an alternative. Until now, that is.
Wärtsilä has more than 20 years’ experience in designing, constructing, and delivering power barges. Its barges are in operation in a variety of global locations from South and East Asia to the Caribbean islands and Central
America. Going forward, Wärtsilä will take advantage of this extensive experience and apply it to designing, constructing, and implementing a new generation of FSRBs, intended to secure access for LNG to locations where it had
previously been impossible or unfeasible to do so.
Using modular designs, Wärtsilä’s FSRBs are configured according to the specific project requirements. This modularity also brings flexibility as it enables the barge to be modified for use in a different place or application. Flexibility in an LNG barge solution is what gives competitive advantage to Wärtsilä. Not only can it be implemented with lower capital expenditure (CAPEX) costs and more quickly than a terminal at a remote location, it can also easily be moved to another location if the market for LNG in one place changes over time. Similarly, a second barge can quickly be added to the same location should demand continue to grow.
Permits are often more straightforward to obtain for a barge than for a land installation, enabling a faster project implementation. The FSRB can be delivered from a shipyard within a clear and controlled timeframe and budget, with highly
controlled quality, compared to a terminal that is subject to local, sometimes arbitrary, construction risks, delays, and quality issues. The controlled schedule and budget significantly reduces the risk of the FSRB project, making it
much easier to achieve funding. Last but not least, it is easier to secure financing for a movable, re-sellable asset, than it is for one at a fixed location.
These days, most floating regasification of LNG is performed by FSRUs. A typical FSRU carries anything from 140,000 m3 of LNG and up, which it supplies to an existing gas pipeline network, such as a national gas grid.
The FSRB, on the other hand, is a smaller-scale solution, storing LNG volumes ranging from 7,500 to 30,000 m3. While an FSRU can sail the seas, an FSRB instead fulfils the same purpose as a small, land-based terminal would. It is stationary, usually situated at the shoreline, or within a few hundred metres of the shore, and only moves if it is decommissioned and transferred to another location.
In addition to lower capital costs, an LNG barge is also more cost efficient than an FSRU from an operational point of view. The barge is remotely operated, requires no crew, and is only visited by operators for inspections and maintenance.
When it comes to the process of delivering LNG to land-based applications in its gaseous form – through the process known as regasification – the FSRB is a differentiator. While FSRUs typically use seawater to heat the LNG to convert it into gas, the FSRB can make use of heat sources at shore, from a power plant for example. Hot water or steam is fed into the regasification module on the barge, where it is cooled while gasifying LNG, and returned to the heat source. In this way, the system performs double work, gasifying the LNG while also cooling the power plant or industrial unit, thereby reducing overall energy consumption. Because of the higher heating media temperatures, the FSRB regasification module is more compact and cost efficient.
If there is no heat source available on shore, the FSRB may also use ambient air vaporisers as a regasification solution for small-scale LNG. Mounted on the barge itself, the vaporisers transfer heat from the air to LNG to transform it into gas. This is a more self-contained process than with seawater, the use of which is restricted in many coastal locations as changing the temperature of seawater can have a negative impact on marine ecosystems.
A key advantage of the at- or near-shore FSRB is that it can also send LNG to shore in its liquid phase. This can be used to load LNG trucks or ISO containers, which will then further extend the small-scale LNG delivery chain to the local
region and beyond.
Wärtsilä is deeply committed to supporting the establishment of LNG as an enabler of sustainable power generation of the future. With its knowledge of LNG technology and extensive experience of delivering power projects with a full Engineering, Procurement & Construction (EPC) scope, Wärtsilä is also uniquely positioned to provide the missing piece in the LNG puzzle, identify, and implement feasible solutions in situations where there are currently no solutions, and provide the know-how, equipment, and infrastructure needed to facilitate growth of the small-scale LNG market around the world.
Author: Raymond Walsh, General Manager, LNG Technology, Wärtsilä Energy Solutions, mail: raymond.walsh@wartsila.com
