The shift toward sustainable electricity systems is one of the grand challenges of the 21st century. Decentralized production from renewable sources, electric mobility, and related advances are at odds with traditional power systems where central, large-scale generation of electricity follows inelastic consumer demand. Information systems innovations can enable new forms of dynamic electricity trading that leverage real-time consumption information and that use price signals to incentivize sustainable consumption behaviors. However, the best designs for these innovations, and the societal implications of different design choices, are largely unclear. We are addressing these challenges through the Power Trading Agent Competition (Power TAC), a competitive gaming platform on which numerous research groups now jointly devise, benchmark, and improve IS-based solutions to the sustainable electricity challenge. Based on the Power TAC community's results, we give preliminary empirical evidence for the efficacy of competitive gaming platforms, and for the community's contributions toward resolving the sustainable electricity challenge.