Research aimed at understanding the role of the affective domain in student learning in classrooms has undergone a recent resurgence due to the need to understand students' affective response to science instruction. In a case study of a year 8 science class in North Queensland, students worked in small groups to write, film, edit, and produce short videos about the socio-scientific issue of coal seam gas mining as part of a unit on energy. Student emotions over the course of the unit of work were recorded using emotion diaries (a self-report measure), video recordings of lessons, and end-of-project interviews. We identify trends in student emotions and analyze their relation to classroom activities using two constructs for interpreting the affective dimension of student learning: emotional energy and emotion regulation. By analyzing a salient classroom event, we report students' regulation of negative emotions like frustration and anger as they worked together to complete the video project successfully. Furthermore, we propose that emotions, particularly positive emotions, elicited by the video task and not the socio-scientific issue dominated students' experiences and perceptions of the unit. This raises questions about how students' positive emotions might be regulated effectively so that they remain focused on the intended learning.