Ecosystem of SG has always attracted novel ideas and latest engineering techniques. As the smartness of power grid progressed the power quality aspects improved drastically. DT has recently continued to flourish and will definitely have great effects on main industries such as SG. At the moment, DT testbeds can provide simulation-based results to facilitate research activities. In parallel, restricted commercialized DT platforms fulfill particular industrial purposes. DT design for any domain of SG is open to ideas and will play definite roles in future SG development. This chapter discusses DT for SG of the future.