This study designed a teaching unit in a chemistry course to engage students in discussing the complex issue of renewable energy development. In the 11-week learning activities, 66 ninth-grade students experienced individual exploration, group collaborative learning, and the operation of a web-based instant response system. Their learning outcomes were measured by the scientific conceptual test and the scientific literacy questionnaire, while their decision-making and argumentation processes were recorded using the instant response system. Results indicated statistically significant gains on the scientific concepts regarding solar cell and energy sources, as well as on the scores of scientific literacy. Likewise, students performed a substantial increase in argumentation skills, especially for those related to evidence-based arguments. Different science achievers showed a mixed pattern in proposing evidence to support their arguments. Using web technology in teaching argumentation on environmental issues is promised to raise students’ interest in acquiring scientific knowledge to deal with relevant issues.