Many researchers have worked on energy efficient policies. But although there is solid evidence that energy efficiency saves money, pollution and carbon, many sound policies and projects have still been collecting dust on the shelves of policy makers, energy suppliers, businesses and consumers. This paper tries to give insight in what aspects of entrepreneurship are important to come to an entrepreneurial venture. The activity of entrepreneurs represents one of the major engines of economic growth, which accounts for a majority of new businesses and hereby jobs are created. This research involves a placement of these new businesses in the context of sustainable economic growth. The process of discovery, evaluation and exploitation of the opportunities will be discussed. Furthermore will a set of individuals who discover, evaluate and exploit them be analysed. This will eventually lead to insight in how entrepreneurs are approaching the market of sustainability.