Benefits of Hydrogen for Combined Heat and Power Systems



By Gavin Dillingham, Ph.D., Program Director, HARC

In the energy space, there is significant discussion around grid decarbonization, or reducing the carbon intensity and level of greenhouse gas emissions per unit of electricity generated. Across the public and private sectors, individuals and groups are identifying, building, and implementing the technologies and projects that will potentially speed up the decarbonization of the power system. As we look to mitigate climate change impacts with a goal of carbon neutrality, it is becoming clearer that although we should be reducing these emissions quickly, our planet is already and will continue to feel the effects of climate change. Extreme weather events are increasing and numerous studies attribute these extreme weather events to a rapidly changing climate and a need for investment in a decarbonized grid.  

It is imperative that as the momentum grows to decarbonize, there is a similar effort to have a more resilient power system. Fortunately, technologies exist that can do both. For nearly a decade, via the U.S. Department of Energy Combined Heat and Power Technical Assistance Partnership (US DOE CHP TAP), HARC has been working in the space of combined heat and power microgrids. Combined heat and power microgrids can be stand-alone CHP systems or can include a variety of other sources including solar and battery storage.  

Our work includes helping communities reduce emissions and improve the resilience of their critical infrastructure. In our most recent webinar, we discuss the use of hydrogen to fuel combined heat and power microgrids. CHP microgrids are already known for their ability to lower operating costs, reduce emissions, and improve site resilience; by using hydrogen the emissions footprint is significantly and further reduced.  

Thanks to recent technological innovations today hydrogen can be mixed in with natural gas and renewable natural gas to reduce the overall emissions profile. Several widely available smaller CHP packaged systems are currently able to use a hydrogen blend fuel; search the CHP eCatalog to learn more. With these changes, it is anticipated that numerous CHP systems will operate on 100% hydrogen by the year 2030. 

This opportunity to produce onsite power and thermal services with a no emission fuel can go a long way in reducing emissions, particularly in sectors that will face difficulty moving to full electrification. While hydrogen is a promising energy source, the emission benefits are largely dependent on the source from which the hydrogen is produced, whether that is grey, blue, or green. Grey hydrogen is the most common and cost-effective form of hydrogen, however, as it is produced from fossil fuels, it has the highest emissions profile of the different types of hydrogen. 

Fortunately, there have been dramatic improvements in the production of blue and green hydrogen. Blue hydrogen comes from the same feedstock, but a carbon capture and storage system is used to capture the carbon from that process resulting in a lower emission fuel source. Green hydrogen has the lowest emission profile; it is produced from water running through an electrolysis process that is fueled by a renewable energy resource.

Hydrogen is poised to play a significant role in our clean energy future, however, that will require a shift from grey to green hydrogen and related technology systems changes. CHP can employ hydrogen as a fuel anywhere there is a need for coincident electric and thermal loads. An example of this is a pilot green hydrogen co-firing CHP operation at Clemson University. This project was developed in partnership with Duke Energy, Siemens, and DOE, and showcases how CHP microgrids, and hydrogen fuel, can be a significant part of your emissions reduction and resilience strategy.

Hydrogen is poised to play a significant role in our clean energy future, however, that will require a shift from grey to green hydrogen and related technology systems changes.

Dr. Gavin Dillingham, HARC