In the United States, utility-scale solar initiatives face growing local resistance despite their cost-competitiveness and potential in mitigating greenhouse gas emissions. This study investigates the marginal effects of knowledge levels related to solar, information treatments, and their interconnections with peoples' attitudes toward utility-scale solar energy systems and explores some key drivers of the different knowledge levels. We designed and implemented a survey targeting both public officials and the general population in the U.S. state of Iowa. Among 862 respondents, 79.8% self-reported having a low level of knowledge about solar energy. Additionally, 77.7% expressed at least moderate support for hosting such projects in their community. Our empirical results suggest that individuals with a higher level of knowledge of utility-scale solar energy tend to express a higher degree of support for adopting such projects within their community. Individuals' attitudes are more responsive to the negative information treatment. Notably, there are significant differences between public officials and the general population in attitudes and responsiveness to information treatments. We also find that landowners' support for utility-scale solar projects is unlikely to change regardless of knowledge levels, while non-landowners show increased support with higher levels of knowledge. This study provides insights for developing context-specific outreach programs to enhance public awareness and support for utility-scale solar projects and promote future solar development.