Design and Construction of a Prototype Micro-combined Heat and Power Unit Operating on an Organic Rankine Cycle Fueled with Hydrogen-enriched Natural Gas Up to 100% Hydrogen

Transitioning to a green hydrogen economy requires end-use applications. Micro-Combined Heat and Power (CHP) systems provide both heat and electric power that can be used in residential homes, apartment complexes, and small commercial operations. In addition to higher overall energy efficiency compared with conventional residential heating units, they offer the added advantage of electrical grid independence.

Most CHP systems use an internal combustion engine (ICE) that drives a generator and uses the waste heat from the exhaust to heat water or produce steam. These ICEs can run conventional petroleum fuels, propane, or natural gas (NG) which offers reduced emissions. The use of an external combustion engine – the Stirling engine (SE) – has attracted much interest and offers the possibility of using hydrogen as the fuel.

However, these units are expensive and there are only two commercially available SE-CHP units, neither currently operating on hydrogen. Likewise, fuel cell CHP units are being developed but none are currently available. More recently CHP units fueled with biomass or NG, based on an organic Rankine cycle (ORC), where the working fluid is a low boiling point hydrocarbon or refrigerant, are attracting interest, but again there are no commercially available units.

This project aims to design, construct, and demonstrate the operation a novel prototype CHP unit operating on an ORC using hydrogen enhanced natural gas (HENG) mixtures with up to 100 vol. % hydrogen as the fuel source. As part of an ongoing project to test and certify natural gas appliances operating on HENG the unit would be evaluated for certification operating on HENG mixtures up to 100 vol. % hydrogen. Having hydrogen-ready certified appliances available when widespread use of green hydrogen becomes available would position Nova Scotia at the forefront of clean energy utilization.


Michael Pegg, Dalhousie University

December 1, 2023 – March 31, 2025