Abstract:
Electrical energy storage has been an interesting research area in the recent years. It is due to the development of renewable energy usage that has been shown as a greater solution to the problem of climate change which is striking the major part of the world nowadays. To reduce the effect of climate change, Rwanda adopted the use of Renewable energies in different sectors including agriculture. Nasho solar powered irrigation scheme is the greatest irrigation project not only in the country but also in the region. This is a project in which solar energy is used to supply the water pumps used in irrigation. This project is an off grid solar power system that adopted batteries energy storage system as an alternative solution to the problem of power outage due to uncertain continuity of solar irradiation. The storage system presents the problem of reduced capacity to supply the water pumps. The major cause of this problem has been described in this research. Hybridization of batteries and super capacitors is proposed as a good solution to the problem stated. Batteries have high specific energy density but a low specific power density. They are combined with super capacitors that have low specific energy density but a high specific power density. The simulation done in matlab/simulink (R2021a_v9.10.0.1602886) proved that super capacitors provide the high current needed by electric motor when it is starting. It is a good solution to the degradation of batteries that were required to supply high current in a very short time while they have a low specific power density. This was the major cause of reduced battery capacity.
