Motivated by a recent surge of research related to energy and sustainability, this paper presents a review of energy-related work within HCI as well as from literature outside of HCI. Our review of energy-related HCI research identifies a central cluster of work focused on electricity consumption feedback (ECF). Our review of literature outside of HCI highlights a number of emerging energy systems trends of strong relevance to HCI and interaction design, including smart grid, demand response, and distributed generation technologies. We conclude by outlining a range of opportunities for HCI to engage with the experiential, behavioral, social, and cultural aspects of these emerging systems, including highlighting new areas for ECF research that move beyond our field's current focus on energy feedback displays to increase awareness and motivate individual conservation behavior.