Title: Combined heat and power with fuel cells or internal combustion engines using nearly green hydrogen for decarbonisation

Authors: Birol Kilkis

Addresses: OSTIM Technical University, OSTIM, 100, Yıl Bul, 55/F 06374, Yenimahalle/Ankara, Türkiye

Abstract: The carbon footprint of fuel-cells and internal combustion engines for cogeneration with green hydrogen are compared. A new definition based on the exergy destructions by the renewable energy systems is introduced for the green hydrogen concept. With six rating and evaluation metrics, 11 major emission-responsible points were identified in comparing fuel cell and internal combustion engine type of combined heat and power. Flat-plate solar panels, and geothermal energy are considered for temperature peaking to replace heat pumps. Results show that they cannot meet the emission minimisation objective. Case studies provide ways and for minimum carbon dioxide emissions responsibility.

Keywords: CO₂ emissions; exergy destruction; fuel cell; combined heat and power; solar and geothermal energy; heat pump.

DOI: 10.1504/IJGW.2025.145099

International Journal of Global Warming, 2025 Vol.35 No.2/3/4, pp.213 - 229

Received: 05 Sep 2023
Accepted: 25 Mar 2024
Published online: 19 Mar 2025 *

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