Balancing Marime Cost versus Risk in the Global Drive for Energy Resilience


past, construcon cost, programme and, oen, perming limitaons for nearshore convenonal LNG terminals and land‐ based regasificaon plants have been prohibive for small to mid‐scale schemes. However, with the introducon of floang liquefacon and regasificaon and storage systems, the capital investment cost, procurement process and construcon schedule can be significantly reduced, as can permissions and environmental restricons in many locaons.


Using figures quoted from the IGU (Internaonal Gas Union, 2016 World LNG Report LNG 18 Conference & Exhibion Edion), onshore terminals averaged capital expenditures (CAPEX) of USD$245 per tonne. For the average floang terminal, this cost is esmated to be halved, at USD$109 per tonne. For a 1.5 MTPA facility, this equates to a saving of USD$200 million. These savings may be overesmated, but there are logic‐based reasons for the trend. Vessels can be designed and built in significantly less me, and for less money, than permanent onshore facilies. Ageing LNG carriers bring greater value to the ship owner in conversion potenal. Storage can be provided offshore/floang as well, allowing flexibility and redundancy in supply. The minimisaon in onshore tanks/infrastructure may result in greater efficiencies both in construcon cost and in perming or environmental approvals, a costly hurdle in many countries.


However, a floang vessel, either a refurbished retrofit LNG carrier, or a specially commissioned process barge, is generally more vulnerable to the metocean condions at a site than an equivalent onshore or convenonal terminal. For such facilies, balancing cost versus risk becomes key.


Floang LNG facility, Caribbean Sea locaon


or regasificaon vessel may not be able to restart its engines in me, requiring it to survive at berth. When mooring floang process barges and vessels, the berthing parameters are uniquely different from those in a convenonal terminal servicing onshore facilies, since quick release mooring hooks are not designed to remain in constant load and fenders are designed to be regularly loaded and unloaded, not kept in constant compression.


Technological innovaon is always driven by operaonal and funconal challenges. So, in response to the parcular expectaons of the industry and, especially, the drive to provide small scale supply at a local level (think Caribbean or Malaysian islands), there are alternave mooring soluons emerging in industry, ranging from structural soluons to berthing/mooring criteria to hose technologies and operaonal innovaons to migate environmental condions. All have the same key objecves: ‐ lower CAPEX, lower OPEX (operaonal expenditure) and opmised berth availability.


Some, such as STL buoys (submerged turret loading), Tower Yoke and spread moorings, have been used in the offshore industry for years. Others, such as FRD (floang regasificaon docks), are sll largely unproven for LNG applicaon.


Floang LNG facility, India


As with any technological advance, tried and tested methods adopted from other comparable sectors/industries typically come with greater cost certainty and known outcomes, whereas innovave concepts bring development risk along with unconfirmed technical feasibility. In a convenonal terminal, mooring lines are the most common way of holding a tanker or other vessel type against a berth. Always, the key assumpon is that the floang body (specifically the LNG carrier) will leave the berth during an extreme event. However, with the adopon of a FLNG terminal, this may not be the case. Specifically, a semi‐permanent storage


Alternave soluons are being considered, adopng technologies from other marine applicaons, such as guide piles and arculated tug barge connecons, to reduce dynamics. Most are waing for their prototype project to prove their value and confirm that the risk is worth the reward. However, over the coming years, with the price of a BTU of gas is not expected to rise significantly, it will be interesng to see which providers are able to navigate the classificaon agencies, risk‐adverse financial backers and technology scepcs, and find opmised design soluons that enable energy resilience. Last decade, it was wind and renewables that drove design ingenuity. Going forward, floang LNG import is proving to be the new froner for marime engineers, smulang some of the most innovave design soluons to meet the demand for affordable and available lower‐emission fuels to local communies and developing countries, worldwide.


Gillian Millar CEng MICE RPEQ Coastal Discipline Leader, Moffa & Nichol


Society of Marime Industries Handbook & Members’ Directory 2018 31


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56