This paper reviews the research work done in the last 11 years in the area of green computing and analyzes the associated hypotheses, which are then structured in taxonomy and explored to pave the way for a comprehensive view of future research in the area. With the help of the taxonomy, we can understand which of the problems needs more attention. For example, when there is a small number of studies related to a problem, research needs to be conducted on this topic, while a huge number of studies could raise contradictory results that can be aggregated to a unified answer with a meta-analysis. Among the hypotheses generated, one can choose to investigate the hypotheses with a sufficient number of papers.