Towards techno-economics of green hydrogen as a primary combustion fuel for recreational vehicle vapor absorption refrigeration system

The drive towards the integration of hydrogen in the global primary energy mix to achieve a carbon–neutral and sustainable society requires both minor and major technological modifications in current energy systems. In this study, the viability of green hydrogen as a combustion fuel and its economics have been investigated for an absorption–desorption-based cooling system. Specially designed burners have been retrofitted with the portable ammonia-water-based cooling system (cooling area: 1.4 ft3). Furthermore, the effect of hydrogen flow and the distance from the burner has been investigated and optimized. The system has been compared with both electrical resistive heating using a 12 V DC power supply and propane gas. An increase in hydrogen flow rate leads to high cooling rates. Furthermore, the reduction in the distance between flame and heating surface improves the heat transfer rate. The system running on hydrogen exhibited highest performance compared to both electricity and propane at optimum flow rate and distance. The optimum flow rate and distance was observed to be 29.2l/h and 2 cm respectively. System running on optimum hydrogen conditions consumed 77.37Wh energy with is 9.10% less compared system running on electric resistance heating and 29% less compared to system running on propane. In terms of carbon–neutral economics, 1 kg of hydrogen can potentially replace 3.28 kg of propane (costing around 3.60 to 4.30 USD). Whereas, 8–9 kg of CO2 reduction can be achieved per kg of hydrogen being used. The 3.30 to 4.30 USD/kg may be considered a competitive cost of green hydrogen in comparison to propane as a combustion fuel for the portable refrigeration sector. These results are the first time, highlighting the efficient use of hydrogen in space cooling.