Friday, April 22, 2011


How does the Alaska natural gas pipeline fit into the overall domestic energy demand picture? The image below is a Sankey diagram of US energy flows based on the 2009 Energy Information Agency Annual Energy Review.

I like this diagram because it shows the relative contribution of various energy sources and puts the Alaska natural gas pipeline into perspective.

The proposed Alaska gas line will deliver 4.5 billion cubic feet per day. In units of "Quads" that equals 1.67 Quads per year. That equals 7% of the current total natural gas demand or 1.7% of the total energy used. If consumed for electrical power it would equal 4.4% of the total energy input for electrical power. Now 2% of all energy or 4.4% of fuel for electricity may not sound like much, but we're talking about a single project.

Compared to Coal: One thing the diagram does not show is the relative efficiency of fuels. Natural gas can be burned for power generation in a combined cycle power plant at efficiencies of 55-60%, an average coal plant converts BTUs to kW at an efficiency of around 33%. On an efficiency basis, new high efficiency gas fired plants can be expected to replace aging coal fired plants.

Compared to Nuclear: Again gas fired combined plants are thermally more efficient than nuclear power plants. Unlike nuclear fuel, natural gas plants don't require cooling water utilities for years after shutdown. Gas fired plants are extremely less expensive to build.

Compared to Oil: Today, with our current infrastructure you can't beat the ease of fueling your vehicle with a petroleum product (gasoline or diesel) and jumping back on the road. On a cost per BTU basis it makes less and less sense to use gasoline or diesel instead of natural gas. You can't beat the concept of switching our motoring paradigm from imported oil to domestic gas. Projects like the Alaska gas pipeline can help make that switch possible. Gas can even be used to produce ultra clean grades of diesel fuel via gas to liquids (GTL) technologies. Gas can also fuel the projects in Canada that recover heavy oil and oil from bituminous sands. Sooner or later natural gas or products of natural gas will fuel your engine.

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