Mitt Romney heaped fresh criticism on the White House green energy agenda Tuesday after the bankruptcy of A123 Systems, a stimulus-backed manufacturer of electric car batteries that President Obama has personally touted.

The company, which won a $249 million Energy Department (DOE) grant for Michigan-based manufacturing in 2009, has an agreement to sell its automotive business to the company Johnson Controls, Inc.

A123’s Chapter 11 filing is fueling new GOP criticism of green energy ventures backed by the 2009 stimulus law. Republicans have repeatedly pointed to the collapse of Solyndra, a solar panel manufacturer that received a $535 million federal loan guarantee, as evidence the program isn’t working.