The mission of the UMass Amherst Energy Transition Institute (ETI) is to enable a fast and fair transition to a decarbonized energy system in the United States. ETI's stakeholder-engaged interdisciplinary research, with a dual focus on technological and human systems, seeks to advance a clean and just energy system throughout its technological and social lifecycle. ETI engages collaboratively with community partners to co-create knowledge that empowers marginalized groups, with particular attention to those vulnerable to harm from climate change or the energy transition. We communicate scientific research relevant to real-world technology and policy decisions in an accessible way. Projects include environmental justice analysis of electricity-system decarbonization, community-engaged co-design of residential electrification for a just and sustainable energy transition, income and racial disparities in financial returns from solar PV deployment, enabling an equitable energy transition through inclusive research, and understanding equity across disciplines.