General Motors has entered into an agreement with Nel Hydrogen U.S., a subsidiary of Norwegian company Nel ASA to develop cheaper sources for renewable hydrogen.
Using GM’s fuel cell knowledge in concert with Nel’s experience with electrolyzers, the pair hope to speed up the development of Nel’s proton exchange membrane (PEM) hydrogen electrolyzer platform.
“General Motors is one of the global leaders in hydrogen fuel cell propulsion with more than 50 years of experience. We believe this collaboration will give us a competitive advantage in industrializing the production of our PEM electrolyzers and further improving the efficiency of our technology,” said Nel ASA’s CEO, Håkon Volldal.
Electrolyzers are one of the best ways to create free hydrogen by splitting water molecules into their hydrogen and oxygen components. The free hydrogen can be stored and used to generate electricity in a fuel cell.
How electrolysis works
According to the U.S. Department of Energy (DoE), “electrolysis is the process of using electricity to split water into hydrogen and oxygen. This reaction takes place in a unit called an electrolyzer. Electrolyzers can range in size from small, appliance-size equipment that is well-suited for small-scale distributed hydrogen production to large-scale, central production facilities.”
An electrolyzer works like a fuel cell in reverse. It uses electricity and water to produce hydrogen and oxygen, while a fuel cell reverses the process, using hydrogen and oxygen to produce electricity and water.
Within the electrolyzer, there is an anode side and cathode side, which are kept separate with a barrier. In the technology being pursued by GM and Nel, that barrier is a polymer Proton Exchange Membrane, or PEM.
In the anode side, water is exposed to electrical current and splits into oxygen, positively charged hydrogen ions known as protons, and electrons. The hydrogen ions pass through the membrane, while the electrons flow through an external circuit to the cathode side. In the cathode, the electrons recombine with the ions to form free H2, or Hydrogen gas, that can be collected and stored.
In addition to PEM electrolyzers, there are also alkaline and solid-state electrolyzer designs, but those are not the subject of the GM/Nel development effort.
Well-suited for renewable energy
Creating free hydrogen for use in fuel cells requires the application of electrical energy. Ideally that energy would come from renewable sources such as solar, which can at times produce an excess of energy that is challenging to store. Hydrogen is a reasonably efficient storage medium, and an electrolyzer requires only water in addition to the electricity, so it is a clean solution. The free oxygen that is produced is an added benefit.
PEM electrolyzers also have the benefit of scalability, and can be as small as a household appliance, producing enough hydrogen to potentially fuel a vehicle at home. Or they can be larger, up to industrial scale.
“Electrolysis is key to creating consistent, clean sources of hydrogen to power fuel cells,” said Charles Freese, GM executive director, Global HYDROTEC. “Nel has some of the most promising electrolyzer technology to help develop clean hydrogen infrastructure, and we believe our HYDROTEC fuel cell IP can help them get closer to scale.”
Inflation Reduction Act provides tax credits
The United States government is backing development of electrolyzer and fuel cell technology. The Inflation Reduction Act, signed into law earlier this year, provides tax credits of up to $3 per kilogram of clean hydrogen.
“This is a fantastic development — and one that completely transforms the outlook for green hydrogen in the U.S.A. The U.S.A. is going to be one of the cheapest places in the world to produce clean hydrogen,” Volldal said.
Europe is also boosting hydrogen production. The EU’s RePowerEU initiative aims for 10 million tons of green hydrogen production within the bloc by 2030, and a further 10 million tons to be imported in the same timeframe. Additionally, several European nations now have their own hydrogen plans. Germany is in the lead with a commitment to billions of euros of investment both domestically and internationally.
“The international picture shows the power of market-based incentives and government support for green hydrogen. We of course hope to see more of the same both in Norway and overseas in the near future,” Volldal said.
The picture for hydrogen is not only commercial, as Nel has also been granted $5.6 million in funding from the U.S. Department of Defense to develop its advanced PEM electrolyzer stack. The goal of the grant is to reduce both operating and capital costs for PEM electrolyzers. That work is being done in collaboration with the U.S. Army’s Engineer Research and Development Center- Construction Engineering Research Laboratory (ERDC- CERL).
High level activities include development of membranes optimized for electrolysis applications, development of advanced catalysts including high volume manufacturing and recycling techniques, surface coating techniques to reduce precious metal usage, and cell stack integration and testing. The project also has options for additional funding.
“Hydrogen generation provides a unique energy source that can be used to support national energy security and resiliency,” said Nicholas Josefik, senior researcher, Energy Branch, ERDC-CERL.
Hydrogen is part of a global solution
As research and development into greener energy continues, hydrogen electrolysis technology is just one of many solutions being considered. The DoE has stated, “Electrolysis is a leading hydrogen production pathway to achieve the Hydrogen Energy Earthshot goal of reducing the cost of clean hydrogen by 80% to $1 per kilogram in one decade.
Hydrogen produced via electrolysis can result in zero greenhouse gas emissions, depending on the source of the electricity used. The source of the required electricity—including its cost and efficiency, as well as emissions resulting from electricity generation—must be considered when evaluating the benefits and economic viability of hydrogen production via electrolysis.”
All players recognize that the source of the electricity used for electrolysis is critical to the green credentials of hydrogen as a storehouse for energy. “In many regions of the country, today’s power grid is not ideal for providing the electricity required for electrolysis because of the greenhouse gases released and the amount of fuel required due to the low efficiency of the electricity generation process,” according to the DoE.
Hydrogen production via electrolysis is best coupled with solar, wind, hydroelectric, geothermal, and even nuclear power generation. All of those generation sources come with their own costs. However, when all costs and benefits are evaluated, it seems likely that hydrogen will find a permanent place in the future energy supply.