The adoption rate of residential solar photovoltaic (PV) systems in the US has grown exponentially in the past two decades. However, from a human-centered design perspective, there is a lack of clear understanding of what current users need and want from solar PV systems and from the experience of installing solar. In this study, we interviewed 18 solar stakeholders and conducted surveys of 1,773 homeowners including both solar adopters and non-adopters in California and Massachusetts. We analyzed the data using discrete choice theory and showed that cost savings, solar system reliability, installer warranty, and reviewer ratings of the installer were the most important factors when these homeowners considered purchasing a solar system. Preference differences were discovered between adopters and non-adopters, and with state, age, and income. Via surveys of current solar adopters' experiences of installing residential solar panels, we found that solar owners ranked installer reliability as even more important than price. The findings are intended to inform designers, engineers, and manufacturers as they create more compelling residential solar PV systems and to inform installers in designing better installation services. The ultimate goal is to promote renewable energy technology and reduce global greenhouse gas emissions. (C) 2019 Elsevier Ltd. All rights reserved.