Design and implementation of a low cost solar PV backup system for low reliability grids

Electricity is the driving force in a country´s economy and the developing world needs reliable low cost electricity for its rapid growth. In light of the challenges faced by these countries, we have proposed a low cost PV based back-up system for critical loads in low grid reliability regions. In addition, the system can also be used in remote places where no access to grid is available. The proposed system extracts maximum available power from PV generator by employing a simplified MPPT algorithm, implemented through a low cost 8-bit microcontroller. The control mechanism ensures that the load and the system components are protected from sudden failures and fluctuating grid power. The control system also maintains the battery at a specified state of charge ensuring a longer battery life and an increased reliability of the system. The whole system was implemented and tested for up to 500W loads which showed highly satisfactory results.