Optimal design and technical analysis of a grid-connected hybrid photovoltaic/diesel/biogas under different economic conditions: A case study

Supplying energy to small villages, which are far from the grid or are located in remote areas, due to the high cost of installing and maintenance of transmission lines, has become a challenge for governments around the world. Since many villages, which are already connected to the grid, suffer from frequent blackouts especially during peak hours of load demand, using a hybridization of renewable resources with regard to the potential in the region is a suitable solution for having more reliable energy and reducing emissions. This paper investigates the use of a hybrid photovoltaics, biomass and diesel to meet the energy needs of a grid-connected village, located in east of Iran. Because of unstable economic conditions and rapid changing of the economic factors in Iran, several possible rates of inflation and discount rates were considered to find an optimal scenario. Before identifying an optimal scenario, a comparison was made to determine which way of installing photovoltaic panels, as centralized plant or top-roof, will be more beneficial in the region. It was concluded that, when the inflation is 10% and discount rate is equal to 18% (most recent economic condition of Iran), the best scenario includes 63 kW photovoltaics, 10 kW biogas generator and 10 kW and 15 kW diesel generator, which could produce energy with 0.193 $/kWh. It was also concluded that with the changes in fuel prices, interest rates, and inflation rates within the reasonable range of expected economic conditions for the project lifetime, the energy cost of the optimal system will vary from 0.085 to 0.238 $/kWh.