Denmark serves as a model of adoption and market integration of renewables—particularly wind power. This success story has resulted from a favorable geographical location, cross-border cooperation with neighboring countries, and a well-struck balance between centralized planning and market-oriented policies. However, the transition between the successful present-day and a future fossil-free Denmark still presents several unresolved conundrums. We identify four challenges in Denmark’s transition to even more renewables. First, greening the transportation sector. Second, reforming the district heating sector while increasing its renewable usage. Third, removing the cost barriers for end-users to adopt electric transportation and heating. Fourth, meeting increasing flexibility requirements alongside dwindling domestic backup capacity. In addition, we identify lessons learned and transferrable experiences for other countries, to determine the extent to which the Danish success story can apply to other regions of the world.