Howard Herzog, a research engineer at MIT's energy and environment lab, cautions that the return of FutureGen isn't without its challenges. "The key barrier for moving ahead is money," he says. "The amount currently committed by government and consortium members is not adequate to fund the original version."

Despite the energy department's renewed commitment, the FutureGen Alliance still needs to come up with $700 million to $900 million to go ahead with what's now estimated as a $2.4 billion project, up from the original $1.5 billion price tag.

The alliance has until January to come up with a more detailed cost estimate and present a full funding plan to the energy department, which must still give its final approval in order for the project to go ahead. "Everything will be reviewed," says Lawrence Pacheco, spokesman for the alliance, which is mostly made up of large electric utilities and coal companies. "Many different options will be considered to reduce cost and technical risk. Once the DOE and alliance make a decision to move full-speed ahead, we will be able to break ground and begin procurement in 2010, with operations beginning in 2014."

Another difference between the original and revived FutureGen is the carbon-capture goal. The early plans called for a 90 percent CO₂ capture rate--a target that won over the support of environmental groups that reluctantly accepted clean coal's role in curbing global greenhouse-gas emissions. The new plan is less ambitious to start, calling for a 60 percent target. But Pacheco says that the higher target is still in play: "The plant will be built to reach, eventually, a 90 percent capture rate."

Mead says that what's important is that the plant be built and demonstrated, allowing utilities to discover many of the unknowns surrounding the technology and share in the FutureGen Alliance's experiences. "It may not have breakthrough or revolutionary features in every step of the process, but together, it's going to be a demonstration of the best we can do today," he says.

The technology in FutureGen, however, is targeted at new power plants and does little to address the more than 600 existing coal plants scattered across the United States. A report released last week from MIT urged the U.S. government to bolster research in post-combustion approaches to reducing CO₂ emissions from coal plants.