Cities occupy approximately 2% of the world territory but account for 70% of the greenhouse emissions and consume almost two thirds of the world’s produced energy. Cities can reduce the negative footprint by transitioning to renewable energy or investing in smart grids. Smart grids cut energy waste and give the consumer a chance to enter the energy market through self-supplying (renewable) energy and rerouting the excesses to the city gird. Smart energy helps cut down energy losses, use energy efficiently and reduce the negative effects on the environment.