Also, NRG Energy and JX Nippon each will contribute about $300 million in equity. This amount includes the company's combined 50% equity interest in Texas Coastal Ventures, the joint venture with Hilcorp Energy that holds the working interests in the West Ranch oil field.

The project's technology was developed jointly by Mitsubishi Heavy Industries and the Kansai Electric Power Co.; it already is being used at 10 natural-gas-fired units overseas and has been tested on a smaller, 25-MW scale for three years at a coal unit at Southern Co.'s Plant Barry in Alabama.

In essence, the project at Parish Unit 8 will divert roughly 40% of the unit's flue-gas emissions to the carbon-capture system. The diverted flue gas will be cooled to the desired temperature, then fed into an absorber, where 90% of the CO₂ will be captured through contact of the flue gas with a special amine-based solvent, which has emerged as the leading method for removing CO₂ from post-combustion flue gases. Then, the CO₂ is stripped from the solvent and compressed for piping to the oil field.

Banskota says that although NRG Energy's current focus is on building the carbon-capture project at Parish Unit 8, the company believes the project could be duplicated at other coal-fired units that are close enough to depleted oil fields that would benefit from CO₂-based enhanced oil recovery.

Banskota says that U.S. oil producers need far more CO₂ than is currently available for use in enhanced oil recovery and that additional carbon-capture projects would help provide it. He says that, at most depleted oil fields, two-thirds or even three-quarters of the oil cannot be recovered through conventional drilling and that enhanced oil recovery is needed to capture most of the rest. According to one estimate, he says, the U.S. could recover 67 billion barrels of oil through enhanced oil recovery.

DOE's Smith notes that NRG Energy's initial plan was to capture CO₂ from only a 60-MW portion of Parish Unit 8's emissions and that, when the company later determined that more CO₂ was needed at the West Ranch oil field to make the project economical, it and JX Nippon quadrupled the project's ability to capture CO₂. That the project could be economical at a larger, more commercial scale is a positive, given the extra energy CCS demands.

Smith adds that he, too, believes the favorable economics of the technology, when tied to significant enhanced oil- recovery opportunities, suggest it will be used in additional projects soon and would enable many newer, more efficient coal units to continue operating even as proposed limits on CO₂ emissions from existing units are implemented.

NRG spokesman David Knox says construction activity is now beginning, with a focus on "building the workforce and acquiring supplies needed to start construction." Knox says initial "work will be clearing the area where the [carbon-capture project] is to be built. Currently, there is a warehouse there."