Many countries around the world are considering using solar energy technologies in their future energy planning. The intermittency and unpredictability nature of solar power generation, which can influence the power quality and reliability of the power grid especially at large-scale solar energy systems, constitute a drawback for use of solar technology. Precise research and investigations are needed to overcome this weakness helping solar power be used in power network in large scale. The variation in sun radiation may lead to over-production of electricity from solar PV generators at one time, and lack of production to satisfy the energy demand at another time. As a result, solar PV systems demonstrate a low-level of reliability in power systems. However, an energy storage technology would play a significant role in increasing the reliability of solar power generation systems. The objectives of this study are: firstly to review the issues in relation to grid-integration of solar PV systems, secondly, to review a range of storage devices that could technically and economically be used in association with solar PV energy in order to increase the solar energy penetration level with appropriate reliability in weak electric systems, and finally to present a model for solar PV system combined with battery and super-capacitor.