In 1987, Brownell served as the Deputy Executive Assistant to Pennsylvania Governor Richard Thornburgh.
Her career in energy began when she served as a Commissioner of the Pennsylvania Public Utility Commission (PUC) from 1997 to 2001.
On April 30, 2001 President George W. Bush nominated Brownell to serve as a Commissioner for the Federal Energy Regulatory Commission.
She has been a Board Member for many corporations including National Grid, Spectra Energy, Oncor Electric Delivery, and Times Publishing Company.
[citation needed] Brownell is a native of Erie, Pennsylvania and attended Syracuse University.