Though LNG plants are large and sophisticated industrial facilities, their inner workings are not rocket science.
The plants are effectively factory-size freezers designed to chill natural gas to minus 162 degrees Celsius—the point at which the fuel becomes liquid and transportable. As with home refrigerators and freezers that use compressors to cool air, LNG facilities use compressors to cool natural gas. Larger LNG plants such as the Gorgon Facility under construction in Australia will run six such compressors (Chevron, 2009). Taken together, these compressors effectively comprise the “heart” of a given LNG plant.
Though an LNG plant has other so-called ancillary energy requirements—think large pumps, valves, and lighting—a given plant’s carbon and air pollution impacts are largely a factor of how it powers its compressors.
LNG producers can run their compressors using either electric motor drives, also known as E-Drives, or gas turbine drives, also known as direct drives or D-Drives. Electricity powers the former—which can be generated from renewable or fossil fuel sources—while the latter operate by burning a portion of the natural gas supply piped into the plant.
Though D-Drives are the more polluting of the two options, they are also the industry’s de facto standard. This is rooted in the industry’s history; early LNG plants were constructed in isolated areas with poor access to electricity infrastructure. Of the 17 plant proposals now on the table in British Columbia, only Pacific Northwest Energy (principally owned by Malaysian energy conglomerate Petronas) and Woodfibre LNG (owned by Woodfibre Natural Gas) explore E-Drives as an option in their respective project descriptions (Stantec, 2013 & Golder Associates, 2013). Without provincial policy directing LNG proponents to install E-Drives, industry will very likely “lock in” to D-Drives at the expense of permanent and secure regional jobs.
In a variety of public remarks and private conversations, British Columbia’s LNG proponents have cited a number of reasons for their lack of interest in E-Drives, including cost, timelines, and perceived reliability of electricity supply.
The core technology underpinning E-Drives is neither new nor sophisticated. They are readily available from established manufacturers, such as Siemens, and are, at this moment, in reliable operation at Statoil’s Snøvit LNG plant, in Norway.
Timelines are certainly a practical consideration for proponents; however a headlong rush to reach market with old technology threatens to cast a pollution shadow that stretches for decades—as a D-Drive plant cannot feasibly be retrofitted for the cleaner alternative. As for affordability, this report finds that E-Drives using renewable electricity translates to a two percent cost premium in the selling price of LNG when compared with their more polluting counterparts.
The Cleanest LNG in the World? concluded that British Columbia’s petroleum industry will not be able to credibly produce the “cleanest LNG in the world” unless and until it powers its plants with E-Drives that in turn run on a combination of new renewable power, existing British Columbia grid electricity, and efficient combined-cycle natural gas generators. That assessment concluded that E-Drives would reduce emissions by the equivalent of 0.11 tonnes of carbon dioxide per tonne of LNG produced.
Clearly, compelling employment and environmental evidence exists for the Government of British Columbia to establish policy that would require or enable the industry to maximize its use of renewable energy through E-Drive technology.
