The Electric Reliability Council of Texas (ERCOT) - which manages 85% of the state's electric load - has released a report on the near-term impacts of proposed federal climate change legislation. Among other things, the report finds that if natural gas prices are $7 per MMBtu, the carbon allowance costs must be between $40 and $60 per ton to reduce carbon emissions in ERCOT generation to 2005 levels, resulting in an annual increase in wholesale power costs of approximately $10 billion.
A copy of the report can be found here, posted by the Texas Public Utility Commission.