The electric power system is being modernized to enable sustainable energy. This chapter presents analyses of different new technologies and solutions for such modernized power systems. Analyses presented include the integration of wind and solar power, electricity consumption, dynamic rating, and energy storage. The main contribution is to considerate effects of weather parameters to find synergies. A national smart grid demonstration project at Gotland island in Sweden has been used as the case study. Results show how the power systems can handle more electricity consumption and generation. The study shows new technology solutions that are beneficial for resource-efficient electricity grids. The case study results show that, most of the time, the energy storage will be unused, but that it can be used to increase the system reliability during that time.