Universities are cradles of innovation, with many start-ups involved in sustainable energy solutions. The extent in which such solutions reach the market and the kind of risk-related factors young firms encounter, are hardly known and understood. We aim to clarify market introduction and focus on the empirics of firms’ risk-taking behavior related to strategic choices, competences, and interactions with (national) ecosystem conditions. We use a unique dataset of almost 110 university spin-off firms and a small selected sample from this set. A total of 60% of spin-offs are able to reach the market, most of them in the first five years of spin-offs’ lives. Wind energy provides the best chances, as compared to such things as solar photovoltaics (PV) and advanced biomass. In-depth results suggest the high probability of quick market introduction in ‘Innovation Leader’ countries, like Sweden and Denmark, if combined with employing rich collaborative networks. A second set of favorable influences includes a practical mindset and accessing substantial investment capital. In contrast, strong risks tend to be connected to activity in fundamental inventions, highly specialized technology, weakly developed (sub) markets, poorly built networks, and short refunding time of substantial investment. This study provides a unique contribution to understanding the market introduction of sustainable energy solutions and risk-taking in this effort by young high-tech firms, among others, connected to differences between countries.