An investigation into the design of a standalone photovoltaic water pumping system for supplying rural areas is presented. It includes a study of system components and their modelling. The PV water pumping system comprises a solar cell array, DC DC buck chopper and permanent magnet DC motor driving a centrifugal pump. Thesis focuses on increasing energy extraction by improving maximum power point tracking (MPPT). P&O MPPT algorithm is investigated which uses to automatically adjust stepsize to better track maximum power point. These use PV source output power and the speed of the DC pump motor as input variables. Both generate pulse width modulation (PWM) control signals to continually adjust the buck converter to maximize power from the PV array, and thus motor speed and the water discharge rate of a centrifugal pump. System elements are individually modelled in MATLAB/SIMULINK and then connected to assess performance under different PV irradiation levels. First, the MP&O MPPT technique is compared with the conventional direct method .The results show that the MP&O MPPT has faster dynamic response and eliminates oscillations around the MPPT under steady state conditions. The MPPT methods are implemented in the simulated PV water pumping system and compared. The results confirm that the new methods have improved energy extraction and dynamic tracking compared with simpler methods.

India is a tropical country which has large amount of available solar radiation which can be harvested and converted to suitable from that is required by the energy utilizing process of our industries. Sago is one of the main food items that are in taken by the most people of India. The raw sago is not consumed directly instead it is processed by sago processing industries which produce processing of a consumable from of sago called starch. The sago include of drying of sago particles in open air convection method or by using electrically operated oven for sago drying. In open air convection the area required for drying sago is more and suitable for large scale processing and the usage of electric oven requires huge amount of electricity for the effective drying of sago particles, to avoid these constraints we have designed an device known as step type solar dryer which use solar energy as its energy source and has high efficiency by reducing the total time for drying out the moisture content in sago particles. We have employed glass covers which the entry of dust particles to the sago particles thereby increase the purity of sago processing. The main advantage of this device is its efficiency in energy conversion of solar radiation it is exposed to it. We hope this device would be transformed in to an essential device in sago processing industries in near future due to its clean and green energy of operations which reduce the cost of production.