Across the EU, significant infrastructure investment is needed in both generation from renewable energy sources (RES) and the electricity grid to meet the European targets on emission reduction and RES expansion. Experiences show, however, that citizens may object to new energy infrastructure in their localities which may cause delays in achieving the targets. To avoid delays, it is crucial to understand what drives people's opinions. To explore people's opinions of different electricity generation and transmission technologies in Ireland, we conducted a nationally-representative survey. Concerning the drivers, we distinguish between socio-demographics, technology-specific perceptions, and energy policy preferences. Our results show that people generally have positive views of RES technologies. While this indicates that Irish citizens agree to move towards cleaner electricity sources, we find reluctance amongst people to have these technologies located close to their places of residence. We find that, across most technologies, the tradeoff people make between economic and environmental policy objectives drives their opinions of, and their tendencies to oppose, technology developments. The significance of most socio-demographic variables, however, is largely technology-dependent. This highlights that policy makers need to understand how people make tradeoffs between policy objectives and how these tradeoffs relate to their opinions of different technologies.