Xcel Energy is planning tests of plug-in hybrid electric vehicles in Boulder.
The plug-ins with vehicle-to-grid technologies would not only charge up from the electricity grid but also discharge power back, essentially acting as mobile energy storage devices.
The first phase of the test involves four cars with special inverters that would allow the utility to pull power from the car's batteries during times of peak power use.
Xcel eventually plans to add 500 plug-ins to the grid and conduct tests involving smart charging stations around Boulder.
The utility is providing $150,000 to launch the project. It said Thursday it is seeking about $6 million in state and federal funding for future phases.