Multi-objective optimisation of a grid-connected hybrid PV-battery system considering battery degradation

Abstract

Variable nature of solar energy leads to inconsistent performance of photovoltaic systems. Integration of photovoltaic systems with storage and grid mitigates variability issues and helps maximise self-consumption. This work presents a design methodology for a grid-connected photovoltaic system integrated with storage to meet an annual hourly average demand of 135 kWh of an establishment situated in northern India which receives a daily average solar insolation of 5.16 kWh/m2. System design has been carried out to meet the energy demand at minimised annualised cost. The annualised cost of the optimised system has been found to be US$115184.20/year. Analysis shows that the proposed model results in reduction in annualised cost by 32.27% and a net reduction in emissions by 610 MT as compared with the traditional grid power. Furthermore, multi-objective optimisation carried out to explore system design trade-offs between annualised cost, peak to average ratio of grid energy, and emissions, indicates that overall reduction in emissions by 15% could be obtained at 6.5% increased cost. It is also observed that reduction in grid-outages by 25% leads to reduction in AC by as high as 42.4%.