It’s hard not to get caught up in the optimism on the exhibition hall at the ARPA-E Innovation Summit, which is taking place this week in the D.C. area. Nearly every booth features a promising—indeed, potentially revolutionary—energy technology concept or prototype. But it’s also hard to ignore the fact that very few of the projects the Department of Energy’s six-year-old agency has funded have made a commercial impact. And with venture funding for energy startups in short supply, it’s worth asking: should the government do more to help commercialize transformative energy technologies? President Obama clearly thinks the answer is yes. His latest budget request for the Department of Energy includes a 21 percent increase for 2017 in clean-energy R&D funding. That includes a 20 percent increase in funding for ARPA-E, which is charged with identifying and investing in promising early-stage technologies. Obama also proposed a so-called “ARPA-E Trust” for developing “larger-scale investment-ready outcomes,” which would begin with $150 million in funding in fiscal 2017 and provide $1.85 billion over five years to ARPA-E.