Heightened concerns over energy prices, energy security, fossil-fuel scarcity, and climate change are spurring a revival of interest in renewable forms of energy in the United States. Potential for significant solar-based energy production has helped place solar policies high on the nation’s policy agenda. This renewed interest comes after more than thirty years of experimentation with solar policies, primarily at the state level. Indeed, since 1974 almost every state adopted some type of financial incentive directed towards encouraging solar-power production and many states adopted and modified multiple types of solar incentives over time. Thus while the current interest in solar power may yield major federal initiatives, historically it has been the state governments – America’s laboratories for policy innovation – that have provided support for solar energy (Rabe 2004) and it may prove the case that support for solar remains primarily a state-level policy. Consequently it is important to understand the factors across the states that affect the adoption of solar incentives. In this paper we perform an event history analysis on solar incentive adoption from 1974 to 2007. Unlike the far majority of event history analyses in public policy studies, which examine policy adoption as a single event, we examine solar-incentive adoption as a multi-event phenomenon with individual states at different points adopting different types of incentives or otherwise changing incentives already in place.