Emission-averse techno-economical study for an isolated microgrid system with solar energy and battery storage

This paper proposes an optimal stochastic operation strategy for renewable energy (RE) supported isolated microgrids (IMGs). It incorporates an emission-averse model to reduce the negative impact of CO2 emission on the environment by optimally utilizing carbon capture-based technology. The emission from dispatchable sources, viz. diesel engines used to produce electrical energy, adversely affects the environment. Although imposing a penalty cost on carbon emissions reduces its production from such sources, but still, it cannot be avoided. The proposed work introduces a carbon capture-based reduced emission model that incorporates a small-scale carbon capture unit (CCU) incorporated with a fossil fuel-based unit. Depending upon the CCU system efficiency, a fractional penalty has also been imposed on carbon emissions. From the analysis point of view, the efficiency of the CCU is considered as 90%. The overall problem is formulated as a multivariable constrained cost optimization problem to obtain the optimal dispatch of various connected sources and is solved through a hybrid function approach using the 'fmincon' solver in the MATLAB environment. The results are analyzed for the techno-economically viability of the IMG system with different RE penetration levels and the carbon emission factor (EF). It is found that the microgrid is operated most economically with a 40% RE penetration (corresponding optimal cost is 1.521e + 03 $), and it is also obtained that with an increase in emission factor, the overall economics of the system is adversely affected considering a certain RE penetration level in the system.