It is extremely important to achieve maximal efficiency of an alternative energy system, as such; it provides the maximum power output. In order to be maximally efficient in utilizing the available energy, researchers will study several key factors that can enable the best sustainable energy in terms of utilizing alternative energies. They have studied several methods to design the best-distributed energy system which implements the alternative energies, energy storage, and the advanced materials for the alternative energy generation. In terms of the solar photovoltaic technologies, e.g., researchers have studied the perovskite solar cells. Perovskite solar cells are highly favored for their wide, tunable band gap and solution process ability. Stellar rise of the perovskite solar cells application partly attributed to factors like high energy efficiency. These factors include innovative design such as the tandem structure, tunable band gap, and encapsulation for each layer. At present, their single-junction efficiencies are comparable to those of multi-crystalline silicon, cadmium telluride and copper indium gallium selenide. Finally, researchers have studied an energy storage system at a capacity of 3MegaWattHour. This system can enable a maximum energy output that entails a system including such key factors as the alternative energy generation, energy storage, and an advantageous distributed energy system.