Hydrogen production from Palm Oil Mill Effluent (POME) biogas via Dry Methane Reforming (DMR), integrated with a Proton Exchange Membrane Fuel Cell (PEMFC), presents a technically and economically viable solution to enhance voltage stability in Indonesia’s 20 kV distribution networks. Process simulation using Aspen HYSYS yielded 1,085 kg/h of hydrogen, stored in three spherical tanks (16.2 m diameter each), and used to power a 2.115 MW PEMFC system with 33.76% electrical efficiency. Grid analysis using PSS® Sincal demonstrated improved voltage levels from 12.51–19.67 kV to 19.5–22.16 kV, eliminating undervoltage and reducing reliance on the 150 kV grid. Economically, the system achieves a revenue-to-cost ratio of 2.42, supported by annual hydrogen revenue of USD 19.05 million and diesel backup cost savings of USD 7.88 million. Financial metrics confirm project viability with a Net Present Value (NPV) of USD 49.58 million, an Internal Rate of Return (IRR) of 53.61%, a payback period of 2.7 years, and a Benefit-Cost Ratio (B/C) of 2.8. The integrated system supports Indonesia’s national targets for 23% renewable energy by 2025 and a 29% GHG emission reduction by 2030. © 2026, Thammasat University. All rights reserved.