Those supporters weren't sure, however, whether they'll try to override the veto or draft another bill. They need two-thirds majorities in both chambers to nullify a veto, and they appeared to be short in the House.
"The people of Kansas expect, and they need, affordable electricity, and so we'll be working to make sure that happens, whether it's a veto override in the next few days or some other way to achieve it," said House Speaker Neufeld, an Ingalls Republican. "We'll just continue to hold options open."
The bill also stripped some power from the secretary of health and environment, who has blocked the two plants because of their potential carbon dioxide emissions. Sunflower Electric Power Corp. wants to build them outside Holcomb, in Finney County.
"There's a lot of people in the Capitol building with an interest in configuring another bill," said Sunflower spokesman Steve Miller. "They all have good ideas."
But Senate President Steve Morris, a Hugoton Republican, promised to attempt an override of "this unfortunate veto." Once legislators formally receive Sebelius' veto message next week, they'll have 30 days to try.
Mark Brownstein, a managing director for Environmental Defense, said the debate in Kansas has been more intense than in other states and that the Legislature's attempt to save coal-fired plants is unusual.
Stephanie Cole, a Sierra Club spokeswoman, said other states' attempts to control greenhouse gas emissions would be damaged if Sunflower builds its plants. Many scientists link CO2 emissions to global warming.
"It sends a message that Kansas is willing to be part of the solution, rather than part of the problem," Cole said. "Kansas is sort of ground zero right now for the global warming debate."
But Ed Legge, spokesman for the Edison Electric Institute, a trade group representing investor-owned utilities, said the veto is not likely to tip the balance away from coal.
"This is an ongoing process, and what we all are trying to figure out is where we're going to get energy in the future," Legge said.
Sebelius also issued an executive order establishing a new advisory council to make recommendations for reducing greenhouse gases.
And she reiterated that she's willing to allow one of the proposed plants, if Sunflower commits to use technology to capture greenhouse gas emissions and develop wind power. Sunflower said such a deal isn't financially feasible.
But Senate Minority Leader Anthony Hensley, a Topeka Democrat who opposed the bill said, "Sometimes in the legislative process, you have to go through these hoops in order to bring people to the table."
The bill is a response to a decision in October by Rod Bremby, secretary of health and environment, to deny an air-quality permit for Sunflower. The Hays-based utility's $3.6 billion project has bipartisan legislative support.
Many legislators, including some of Sebelius' fellow Democrats, saw Bremby's decision as arbitrary because the state has no rules on CO2 emissions. They argued the decision made Kansas less business-friendly and made future power shortages more likely.
Only days before the veto, Neufeld and other Republican legislators said Kansas had been passed over for a proposed $10 billion refinery because its regulatory environment was too uncertain. Sebelius' administration disputed the claim.
On Friday, Earl Watkins Jr., Sunflower's chief executive officer, said: "If not resolved, this veto will unnecessarily raise electric rates for Kansas families and punish our Kansas workers and industries."
Sunflower and a sister company serve about 400,000 customers in 55 western Kansas counties. Its two plants would have a combined generating capacity of 1,400 megawatts, enough to supply the peak electric needs of 700,000 households, according to one state estimate.
Initially, two out-of-state partners of Sunflower's would claim 86 percent of the new power, something critics of the project noted often in suggesting Kansas doesn't need both plants. But supporters of the bill said exporting electricity would be like exporting any other product.
Sebelius objected strongly to provisions in the bill limiting the secretary's power to deny air-quality permits for such projects and to block him from writing new emissions standards without the Legislature's approval.
Sunflower estimated that its new plants would produce 11 million tons of CO2 a year. The utility planned a bioenergy center for capturing all but 4.5 million tons and using it to grow algae that could be converted to fuel. Critics said the technology is too experimental.
The bill's supporters hoped to win over some reluctant legislators by including provisions in the bill to give utilities a financial incentive to help consumers conserve power and to encourage homes and businesses to use solar-power generators.
The most significant "green" provision mandated that renewable resources, such as wind, account for 10 percent of each investor-owned utility's and electric cooperative's generating capacity by 2012. The figure would rise to 20 percent by 2020.
But environmentalists said the benefits from such provisions were far outweighed by allowing the two coal-fired plants.