Regasifying and storing LNG offshore has allowed customers to import gas without committing to land-based infrastructure. The option also speeds up access to vast amounts of energy.

“Wärtsilä focuses on completing the LNG value chain,” says Timo Koponen, Vice President, Flow and Gas Solutions, Wärtsilä. “It’s basically creating an alternative to pipeline gas. The whole logic of the Floating Storage and Regasification Units (FSRUs) is to provide a floating receiving terminal that has a regasification plant on board, plus LNG storage tanks.”

The end users vary, from industrial clients connected to smaller FSRUs – essentially an LNG carrier equiped by the addition of on-board storage and regas facilities – to large utilities.

Last year, Hyundai Heavy Industries (HHI) ordered Wärtsilä seawater/propane based regasification modules for two FSRU customers, Höegh LNG and Gazprom.

A bait for all types of consumers is expediency.

“It’s just a more flexible and faster way to get the gas imported,” Koponen points out. “It allows new importers and that’s why it has become popular, it’s a faster way to kick off gas imports, and it is in many cases much easier to build offshore and not invest in expensive and very bureaucratic onshore terminals, plus the vessel can be deployed to another location. It’s not tied to land forever.”

And there’s the question of size. Part of marketing the idea of FSRUs to customers has been about communicating how much energy they store, underlines Reidar Strande, Director Midstream, Wärtsilä Gas Solutions, because not everyone truly understands how much energy LNG contains. Each of these FSRUs has a sendout capacity corresponding to electrical power of 2500 MW, similar to that of a nuclear power plant. “When you go from gas to LNG, you increase the energy content per unit volume by a factor of 600, so you’re bringing enormous amounts of energy with you,” he says.

And then there’s the question of speed. It isn’t simply a question of a lot of energy, but of a lot of energy delivered very quickly. “An FSRU new-build takes on average three years to build, a retrofit maybe two,” Strande says. “Compare that to the timescale of setting up other plants – buying the land, getting the permit.”

In some places, FSRUs can also add competition to the energy market. Wärtsilä and Hyundai Heavy Industry delivered an FSRU christened the Independence to Lithuania a few years ago. Once the two 170,000 m3storage capacity vessels were in place, the country eventually saw Russian pipeline gas become cheaper.

And while on the topic of Lithuania, it’s worth noting that technically it’s an ideal customer for a very specific Wärtsilä technology because of the grim winters.

 “[Other FSRUs] use only seawater to provide heat for vaporisation, but this runs the risk of frozen seawater clogging the heat exchangers,” explains Kenneth Engblom, Director, Business Development LNG, Wärtsilä. “Instead, Wärtsilä uses propane and seawater in a cascade loop to warm the LNG.”

Other technologies also offer ways to deal with the cold, but often at great fuel cost. Wärtsilä can thus bring down the price tag of regasifying in colder climates.

So cheaper, faster, bigger… a final advantage to FSRUs is the fact that they can be moved. “They are typically leased over a 10- to 15-year contract,” Strande explains. “Which brings down the capital expenditure compared to a project on land.”