American utility consumers face a compelling generational challenge: satisfy the need for a reliable power supply, at a reasonable price, while also reducing greenhouse-gas emissions and building...
The Carbon Conundrum
(see Chart 2). But while carbon sequestration in oil and gas wells looks promising, one big hurdle is simply getting the CO 2 from its production source to the oil field site. With the exception of Texas, most oil and gas reservoirs are not located close to power plants. It's no secret that adding miles of CO 2 transportation will add substantially to the costs of sequestration.
The good news is that another type of geologic formation promises even more storage potential than oil and gas formations. Deep saline aquifers, aka deep brine formations, are projected to have enough storage capacity for 10,000 gigatonnes of carbon. Put another way, saline aquifers alone could store Europe's entire CO 2 production for the next 400 years, Klara says. "Saline storage blows away oil and gas capacity." (For other sequestration possibilities, see Figure 1.)
The Sleipner project off the coast of Norway is the first to try to exploit a deep saline aquifer for carbon sequestration. The big unknown with deep saline carbon storage is just how permanent that storage is. Sleipner is also an EOR project, sitting in the North Sea atop a huge gas field. Periodic seismic shoots-seismic measurements designed to assess changes in seismic amplitudes-have shown an increasing volume in the Utsira saline formation.
But the jury is out on whether Sleipner and the Utsira formation are a successful carbon sequestration experiment. Herzog says that since the aquifer is under the seabed, it's a very difficult site to monitor closely. "It looks pretty good and isn't showing any problems," he says, "but just because it's not showing problems doesn't mean there aren't any." He points out that the project is only 7 years old-the blink of an eye, geologically speaking. Also, due to the difficulty in monitoring the site, Herzog says it is too much of a jump to say that there are no leaks at all at Sleipner.
Talk of leaks at Sleipner makes Klara a little testy. "There are more unsubstantiated claims of leakage than evidence," he says. In fact, he says, "there's absolutely no evidence" of leakage at Sleipner.
But there's also little doubt that a land-based sequestration project using a saline aquifer could quiet critics and doubters of Sleipner. That may be where FutureGen comes in.
FutureGen, Gasification, and the Future of Sequestration
In February, Energy Secretary Abraham announced FutureGen to great fanfare. Billed as the world's cleanest full-scale fossil fuel power plant, the $1 billion project, basically a large-scale testing lab, will use industry partners to design, build, and operate the first coal-fired, emissions-free power plant. In addition, FutureGen will be the first power plant designed to sequester greenhouse gases and to provide a new source of hydrogen.
The Department of Energy (DOE) solicited a Request for Information (RFI) from potential industry partners in the spring. The results of the RFI are expected to be released in mid-July, shortly after press time. While the RFI results may give more particulars, a couple of things about the project are already certain, says George Rudins, deputy assistant secretary for