After a succession of jobs and projects in the nonprofit sector and an early internet startup, he gained attention after 2002 as the founder of the California Cars Initiative, promoting mass production of plug-in hybrid electric vehicles.
He built the company with a small international staff, raised angel funding and remained as CEO until it was bought in early 2001.
[5] In 2001, interrupted by surgery for an acoustic neuroma, Kramer moved his focus from high-tech back to his earlier environmental concerns.
He approached Amory Lovins of the Rocky Mountain Institute (RMI), and entered into discussions with RMI-spinoff HyperCar to advance its concept of a fully optimized, 99 mile/gallon, fuel-cell-powered SUV.
[7] Within four years, many of the major automakers began to offer some type of plug-in hybrid or all-electric vehicle, beginning with the Chevrolet Volt.
"[8] His activities and writing about global warming emerged from his work on plug-in cars as he focused on powering electric vehicles by renewable energy.
[13] On climate change and clean energy, he has authored or co-authored with renewable energy experts and advocates including Dan Kammen, Gil Friend, and Hunter Lovins, op-ed pieces for the Huffington Post, the San Jose Mercury-News, Salon, Grist, Alternet, The Guardian and the Houston Chronicle.