Blockchain has known a rapid rise in the last few years since it promises solutions for the decentralization of many traditional systems. Although it has gained a lot of interest, in most of the cases the current technology is not ready yet for production use. In this presentation, we will first make a short introduction to the technical aspects of the blockchain technology and continue with the challenges that arise from integrating real time systems with blockchain. We will then focus on the problems and opportunities of developing solutions for Smart Grids using blockchain.