Techno-economic evaluation of an off-grid hybrid PV-wind-diesel-battery system with various scenarios of system?s renewable energy fraction

An off-grid hybrid PV-wind-diesel-battery system with the best hybrid combination of system?s components is designed to fulfill the electricity demand an off-grid village. For this purpose, five scenarios of system?s renewable energy fractions (namely 0% renewable energy, 25% renewable energy, 50% renewable energy, 75% renewable energy and 100% renewable energy) were modeled, simulated, optimized and analyzed. The results obtained using the Hybrid Optimization of Multiple Energy Resources (HOMER) software of the National Renewable Energy Laboratory (NREL)/USA showed that the hybrid system with 50% renewable energy fraction is the optimal one in terms of both its technical performance and the cost of generated electricity which was found to be $0.202/kWh. It was also proved that deploying this system for electricity generation reduces the emissions by 49% compared to the conventional system comprising only diesel generator sets. Moreover, a sensitivity analysis was conducted to reveal the impact of diesel prices, solar radiation and wind speed on the cost of generated ? by this optimal system ? electricity. The obtained results indicated that diesel price is the most influential factor in the cost of generated electricity. It changes from $0.168/kWh to $0.0.237/kWh for a variation in diesel prices from ?30% to +30% of its current prices. The effect of battery bank?s storage capacity on the performance and cost of electricity, generated by the optimal system was investigated as well. The results showed that varying the storage capacity from ?30% to +30% (from the base case value of 2971 kWh) increases the hybrid system?s capital cost, but reduces each of the excess electricity, diesel generators operation hours, the annual diesel consumption and consequently the CO2 emissions. However, increasing the storage capacity from ?30% till 0% (the base case), reduces the cost of electricity, while increasing the storage capacity from the base case of 0% to +30% does not affect the cost of generated electricity.

Automated summary

An off-grid hybrid PV-wind-diesel-battery system with 50% renewable energy fraction was found to be the optimal choice in terms of technical performance and cost of electricity generation. Sensitivity analysis revealed that diesel price is the most influential factor affecting the cost of generated electricity. The study also showed that varying the storage capacity of the battery bank has complex effects on system performance and cost.