Let’s go to Washington D.C. this morning, where the Department of Energy is holding an annual summit for its ARPA-E program. The DARPA-modeled program has invested some $400 million into 121 projects representing the risky cutting edge of clean energy and green technology, and the Obama Administration is seeking $550 million more in the 2012 fiscal year budget. But with federal programs supporting green technology under attack on multiple fronts, it’s possible that the program’s budget could be drastically cut next year. Energy Secretary Steven Chu opened Tuesday’s summit with a keynote speech positioning ARPA-E as a critical part of the United States’ strategy to retain its technological lead against Europe and China in industries from solar and wind power and advanced battery technology to more energy-efficient buildings and power grid systems. That’s just a start to the list of technologies that are being worked on by companies and research institutions using ARPA-E funding, including a few startups that have recently raised additional private investment, such as Transphorm and Phononic Devices. Earth2Tech’s Katie Fehrenbacher is at the conference this morning — stay tuned for more updates.