In this episode of Earthlings 2.0, we sit down with Aaron Goodman, CEO and co-founder of Petra Power, to explore a practical bridge solution for hard-to-abate sectors like trucking, shipping, and defense. As hydrogen infrastructure remains limited, Aaron explains how solid oxide fuel cells can convert diesel or hydrogen directly into electricity without combustion, and even reverse the process to generate hydrogen from electricity. We discuss why Petra Power is targeting auxiliary power units (APUs) on heavy-duty trucks rather than replacing engines outright, how support from the Department of Defense helped accelerate development, and why incremental efficiency gains may be more realistic than sweeping infrastructure overhauls in the next decade.