This chapter deals with small high-technology firms introducing sustainable energy inventions to the market. The focus is on university spin-offs, which typically show weak skills in management and marketing, but strong technology skills – in this chapter, solar photovoltaics, wind energy, biomass and hydro-power. A simplified conceptual model is explored by focusing on institutional aspects (countries) and network access as well as firms’ entrepreneurial orientation. The exploration of time to market draws on a selected sample of spin-offs in northwest Europe using rough-set analysis. The results show that the highest probability for quick market introduction occurs in an ‘innovation leader’ country (Sweden, Denmark, Finland) and among spin-offs’ involved in multiple networks, followed by those with a practical orientation and access to substantial investment. There are no differences between entrepreneurial ecosystems in metropolitan areas and remote/small urban places. Rather, the results indicate a trend for compensation in ‘thin regions’ through long-distance networks and ‘workplace learning’.