[Paper Review] HyMGP: A Customized MILP-Based Tool for Techno-Economic Planning of Islanded Microgrids

Andres Intriago, Rongxing Hu+10 more|arXiv (Cornell University)|Jan 15, 2026

Hybrid Renewable Energy Systems0 citations

TL;DR

HyMGP is a customized MILP-based tool for techno-economic planning of islanded microgrids, benchmarked against HOMER Pro, and demonstrates how wind and Li-ion BESS can reduce NPC in a Saudi desert standalone microgrid. It also analyzes battery autonomy effects and compares lead-acid vs Li-ion storage.

ABSTRACT

This paper presents a customized microgrid planning algorithm and tool, HyMGP, for remote sites in arid regions, which is formulated as a Mixed Integer Linear Programming (MILP) problem. HyMGP is compared with HOMER Pro to evaluate its performance in optimizing the sizing of microgrid components, including photovoltaic panels (PVs), vertical axis wind turbines (VAWTs), and battery energy storage systems (BESS), for remote and off-grid applications. The study focuses on a standalone microgrid in the Saudi Arabia, considering high solar irradiance, limited wind availability, and a constant load profile composed of continuous cathodic protection and daytime cooling. In the simulation environment, comparisons with HOMER solutions demonstrate the advantages of HyMGP, which provides optimal and more flexible solutions by allowing user-defined component specifications and strictly enforcing all constraints. Further analysis shows that incorporating wind turbines reduces the Net Present Cost (NPC) by decreasing the required PV and battery capacities. Increasing battery autonomy leads to a higher NPC in both PV-only and hybrid systems due to the need for larger storage. Finally, lithium iron phosphate (Li-ion LFP) batteries are found to be more cost effective than lead acid, offering lower NPCs due to their longer lifespan, deeper discharge capability, and fewer replacement cycles.

Motivation & Objective

• Develop a MILP-based microgrid planning algorithm tailored for remote desert sites.
• Compare HyMGP results with HOMER Pro to show advantages in constraint handling and optimality.
• Evaluate the impact of wind integration and battery autonomy on total net present cost (NPC).
• Assess cost-effectiveness of Li-ion LFP versus lead-acid BESS in standalone microgrids.

Proposed method

• Formulate microgrid planning as a MILP to minimize NPC over a 25-year horizon.
• Define decision variables for the number of PV, WT, and BESS units with investment and operating costs.
• Incorporate operational constraints for PV, WT, and BESS including SOC, charging/discharging, and reserve requirements.
• Allow controlled unserved load and unmet reserve to balance cost and reliability.
• Solve with Gurobi in MATLAB and compare results to HOMER Pro across scenarios.

Experimental results

Research questions

• RQ1 How does HyMGP optimize component sizing (PV, WT, BESS) to minimize NPC for islanded microgrids?
• RQ2 What are the comparative advantages of HyMGP over HOMER Pro in terms of constraint enforcement and optimality?
• RQ3 How do wind integration and battery autonomy affect NPC and system design?
• RQ4 Are Li-ion LFP batteries more cost-effective than lead-acid batteries in long-term standalone microgrids?

Key findings

• Wind integration reduces NPC by decreasing PV and BESS sizing (18%, 28%, 23% reductions in the three cases).
• Allowing small unmet load (0.05%) lowers NPC by 5.4% for PV-only and 10.8% for PV+WT cases.
• HyMGP achieves solutions with strictly satisfied constraints and can yield up to 10% lower NPC than HOMER for PV+WT under comparable unmet-load levels.
• Li-ion LFP batteries are more cost-effective than lead-acid, with NPC reductions of 5.54% (PV) and 7.48% (PV+WT) at zero unmet load, increasing with unmet-load allowances.
• Increasing battery autonomy narrows the cost difference between PV-only and hybrid systems due to storage dominance.
• Inclusion of wind reduces required renewable capacity and storage, improving overall economics.