About 17% of global population lack access to electricity and around 80% of them are in remote areas. One of the solutions to this problem could be remote microgrids, which are a small-scale power supply network designed to power small communities within clearly defined electrical boundaries. The reduction in the cost of electricity in such microgrids can make electricity accessible in remote locations. Renewable energy integration and use of batteries in diesel-based microgrids have been effective in the reduction of fuel consumption. A battery can enhance generator or load in microgrid operation to ensure full load operation. Moreover, battery improves photovoltaic (PV) utilization by storing extra energy. However, due to low lifetime of batteries, the operational cost increases. In addition, batteries have limited energy throughput. Hence, a balance between fuel consumption and battery lifetime throughput is required to lower the operational cost.
A two-layer coordinated control approach for power management can be used for remote microgrids. These two layers are schedule and dispatch layers. Power set points of dispatchable energy resources are calculated in the schedule layer and these scheduled set points are dispatched in real time in the dispatch layer. A novel algorithm considering battery lifetime is proposed to reduce the operational cost of the microgrid. This method can help to reduce battery wear cost and fuel cost. The effectiveness of this method was evaluated through a simulation study of PV-diesel hybrid microgrid, which consists of a 27 kW PV system, 30 kW and 75 kW diesel generators, 170 kWh lead acid battery bank and residential load with annual peak demand of 64 kW. The results from the simulation showed improvement of battery lifetime from 1.42 to 5.28 years and reduction in the operational cost by 9%.
- Prolongs battery life
- Reduces operational cost of the remote microgrid system