The amount of data generated by smart grids is increasing rapidly, and scientists are trying to find ways to analyse this data to make the grids more efficient. Big data is a new field of research that will become more and more important in the future. Big data can be used to analyse data from smart grids, and this analysis can help make the grids more efficient. In this paper we will discuss how big data can be used to analyse data from smart grids, and how this analysis can be used to make the grids more efficient. Finally, we will outline some of the open problems in this area that need to be solved in future research.