Innovative Design of Excess Electricity Usage from an Islanding Micro-Hydroturbine System as an Alternative to Dump Load. A Case Study of Hhaynu River – Mbulu, Tanzania

In rural electrification projects, microhydro turbine systems are suitable for supplying electricity to off-grid areas where water resources are available. The design configuration of micro-hydro turbine systems consists of a water intake system, turbine system and generator system. The power of the water drives the turbine to produce mechanical power that drives the generator to produce electrical power that is supplied to the load demand. In many off-grid and rural areas of developing countries such as Tanzania, where the population density is low, the energy demand is relatively low compared to the power supply at most times of the day. To bridge this gap with the existing microhydro turbine system design, new knowledge on energy storage technologies needs to be studied. This phenomenon is demonstrated in this research project by using hydrogen energy storage. The available excess electricity, instead of being stored into the batteries or sent to dump ballast loads, is used to power the electrolyser system that produces hydrogen gas, which is stored as energy. This new energy utilization approach has been proven to increase the energy storage capacity by eliminating 68.37% of the excess energy needed for the dump load and increasing the excess energy storage from 31.63% for the battery system to 100% for the electrolyser system.