*1.2. Research Contribution*

In view of the above, the main contribution of this work is to introduce a suitable cost-effective framework for incorporating short-term flexibility managemen<sup>t</sup> requirements into the long-term planning of renewable energy-based microgrid. The total cost of investment and flexibility management, and the supply reliability requirements are investigated and compared under different system design scenarios using the multi-objective optimization approach. The effectiveness of ensembled data-driven renewable energy generation forecasting using the Gradient Boosted regression trees (GBRT) techniques for DSM/DRP flexibility planning and efficient coordination of FDRs is analyzed and compared with the critical peak pricing DRP alternative. The economic advantage of using PHES, compared to BESS, in microgrid applications that requires high renewable energy fraction has been demonstrated through simulation using the data for a real Kenyan microgrid case study.

The rest of the paper is organized as follows; Section 2 presents the methodology and system modeling, Section 3 provides an overview of the FDR, and the techniques of each DRP is described. The optimization problems are formulated in Section 4 while Section 5 provided the details of the case study and simulation parameters, simulation results are outlined and discussed in Section 6 and finally, Section 7 provides the conclusion of the work.
