AUSTIN – New homes in Texas would have to be at least 15 percent more efficient in energy use and new appliances would have to use significantly less electricity under clean-air legislation that the Senate tentatively approved on Wednesday.

Also under the bill, Texans who purchase plug-in hybrid motor vehicles – now being developed by most major automakers – would qualify for $4,000 rebates.

The measure was tentatively approved on a 22-9 vote and must receive one more vote in the chamber before it moves to the House. All nine votes in opposition were cast by Republicans.

Senate Natural Resources Committee Chairman Kip Averitt, R-Waco, pointed out that his bill also would require three state agencies – including the Texas Commission on Environmental Quality – to begin preparing for new federal global-warming regulations.

"If and when the feds decide to adopt climate-change-related regulations, we want to be in a proactive position, because we have more to lose in that situation than any other state in the union," Averitt said.

Another provision in the bill would create a new grant program to encourage more innovative clean-air technologies. The environmental commission and two other agencies with jurisdiction over energy and natural resources would work jointly on the program.

"It's another aggressive step forward to implement cutting-edge technologies," Averitt said. "We're going to put some of the state's smartest people together at the same table and allow them to incentivize new technologies so that the state can help get those technologies to the market faster."

Continuing an existing program, the bill also contains $100 million in incentives for Texans who replace old, polluting vehicles.

And the legislation would allow state regulators to consider the cumulative effects of multiple permits for industrial polluters rather than just the impact of single permits.

That provision caused some Republicans to oppose the measure.