Hydrogen is the smallest and most abundant element in the universe. It is lighter than air and produces heat energy when burned. Hydrogen gas is easily generated through a process called electrolysis, which involves running an electric current through salt water. Humans have been able to produce hydrogen for over 200 years but have rarely found a valuable purpose for it.
Early in the 20th century, people tried filling massive balloons with hydrogen, using them to float airships which carried passengers on what were essentially pleasure cruises. Like Frisbees, airships are often referred to by their most famous manufacturer Luftschiffbau Zeppelin. However, in 1937, an improbable and well-publicized accident with the world’s largest airship, the Hindenburg, put a quick end to this fad.
The United States has been rapidly deploying renewable energy systems like wind and solar in recent years, adding 17.6 gigawatts of solar alone in the last year — a 34% increase in the nation’s total solar deployment. Large amounts of energy can be produced on sunny or windy days, but these common renewable energy producers are not always active during peak electricity demand times.
Electric energy must be used at the same rate it is produced. If a renewable energy producer is producing more than is demanded, and there is no option for storing energy, its production is “curtailed” or stopped. This curtailment of a renewable energy producer can be thought of as a loss of energy, and it is happening more and more each year. In 2020, California curtailed what would have been 5% of its total solar power output that year, according to the U.S. Energy Information Administration. Storing renewable energy has been a constant challenge to full utilization of renewable sources. However, researchers are looking to hydrogen to solve this storage issue.
In January 2023, the University of Wisconsin-Madison will open the Hydrogen and Electrochemical Research for Decarbonization (HERD) Lab, directed by Dr. Luca Mastropasqua, an assistant professor in mechanical engineering. The lab is focused on using hydrogen to make decarbonized systems — which reduce carbon emissions — for power generation, energy storage and industrial applications.
“If you can produce hydrogen in a renewable fashion then you can use [it] as a carrier of renewable energy,” said Dr. Mastropasqua.
Energy produced by wind and solar can then be used in industrial processes such as cement, steel or chemical production, sectors which have not had solutions for decarbonization, according to Dr. Mastropasqua. These industries emit 2.3 gigatons (Gt) or 6.2% of global CO2 emissions, 3.3 Gt or 9%, and 2 Gt or 5.4%, respectively. This is about a fifth of global emissions which are overdue for decarbonization solutions.
Hydrogen gas is difficult to contain because it is small enough to fit through even the tiniest crack. At room temperature, hydrogen molecules are gaseous at normal temperature and pressure. If compared by weight, hydrogen contains more energy than other fuels but when compared by volume, hydrogen takes up much more space unless it is compressed or liquified — both processes which take energy and good safety practices.
Up until now, hydrogen did not have many feasible (or profitable) applications outside of a few chemical production processes, so little funding has gone into researching new hydrogen technologies, according to Dr. Mastropasqua. This has left both electrolysis and hydrogen storage as areas ripe for research and innovation.
The most common way people may think of energy storage is through batteries, such as the process of charging our phones with their nickel-cadmium or lithium-ion chemical batteries. However, at the scale of an energy grid, energy storage looks a little different.
Globally, 94% of existing energy storage is pumped hydro. Pumped hydro stores energy by pumping water into an elevated holding tank during periods of excess energy production. When there is high energy demand, the water is funneled back downward and through turbines which generate electricity. Pumped hydro facilities have massive footprints which disrupt environments and water cycles, so environmental regulations in the U.S. have limited their development in recent decades, according to the Federal Energy Regulatory Commission.
Similarly, hydrogen can act as a storage mechanism but on a molecular level. At times of high energy production, excess energy can be used to perform electrolysis and hydrogen can be stored in many ways: large gas tanks, enormous underground caverns, combined with other chemicals, such as ammonia, to reduce storage challenges, or, given the right circumstances, within the existing natural gas systems.
In 2021, the Biden Administration announced “The Hydrogen Shot,” which “establishes a framework and foundation for clean hydrogen,” according to the Department of Energy (DOE). The initiative, which echoes President Kennedy’s “Moonshot,” aims to reduce the cost of producing hydrogen to “one dollar per kilogram in one decade.” Biden’s initiative promises DOE resources and incentives to get there. One of these resources is the Regional Clean Hydrogen Hubs program.
Wisconsin Gov.Tony Evers announced two efforts with nearby states to submit proposals for funding from the federal Hydrogen Hubs program. These hubs aim to connect hydrogen producers, researchers and consumers in order to increase the use of hydrogen as a clean energy carrier. Wisconsin’s flagship universities are certain to play a role in the development of these proposals.
“Right now across the U.S., people, including us, are focusing their work in developing hydrogen hubs. There will be between four and eight across the U.S. by the time they get funded and those are regional hydrogen hubs that will coordinate with each other. Their goal will be to research, demonstrate, design and build hydrogen projects,” said Dr. Mastropasqua. “Every person I talk to in the hydrogen field is basically coordinating for that. The legislation has had a major effect on the industry and on the research, so it’s an exciting time.”
Dr. Mastropasqua said he is moving from the University of California-Irvine to UW-Madison to continue his research in hydrogen because of the state’s proximity to water and wind resources. Wisconsin also has several industries, particularly in concrete and metals production, which currently lack decarbonization solutions. Proximity to these industries could allow the HERD Lab to perform groundbreaking experiments and immediate reduction in fossil fuel emissions, he said.
“There is some research that needs to be done, not in the lab because these things are difficult to reproduce in the lab as compared to real life,” said Dr. Mastropasqua.
Wisconsin has had a long history in renewable energy innovation. The state lacks fossil fuel resources, so Wisconsinites have found creative ways to meet their energy needs. For example, the Wisconsin River is known as “the hardest working river in the nation,” a nickname it earned for having nearly 50 hydropower facilities — more than any other river in the U.S.
WEC Energy Group manages utilities in Wisconsin and surrounding states. Their energy production portfolio includes 20 years of wind farms, more than 100 years of hydropower and even a nuclear plant which it no longer manages.
“We've long had a commitment to renewable energy, carbon free energy,” said Brendan Conway, director of media relations for WEC Energy Group.
In mid-October, a natural gas power plant in Upper Michigan tested blending hydrogen with natural gas as part of a first-of-its-kind experimental pilot program. Michigan Energy Resources, a subsidiary of WEC Energy Group, partnered with the Electric Power Research Institute to conduct this experiment. While they have yet to release complete findings of the experiment, the simple fact that these natural gas units could operate for a week using a hydrogen and natural gas blended fuel is evidence for using existing natural gas systems for clean energy storage through hydrogen.
Gas transmission lines are an immediate storage option for cleanly produced hydrogen. The United States has 3 million miles of natural gas pipelines which delivered 27.7 trillion cubic feet of natural gas in 2020, according to the U.S. Energy Information Administration.
“If you consider you just convert 5% volume of natural gas into hydrogen, you are able to store massive amounts of renewables into the natural gas pipelines,” said Dr. Mastropasqua. “The natural gas grid can become a hydrogen storage system, and so a renewable energy storage system.”
Countries like the United Kingdom, the Netherlands and Japan allow between 12% and 20% mixtures of hydrogen into natural gas lines while the United States only allows five percent, even for experiments, according to Dr. Mastropasqua.
“We are suggesting to policymakers that they should allow portions of the natural gas grid to be converted so we can actually study the long term effect of hydrogen on the grid,” he noted.
Using hydrogen this way would also be an immediate effort towards decarbonizing the electric grid, Dr. Mastropasqua added. Research in renewable energy technologies is important for climate and economic reasons, but Dr. Mastropasqua also emphasized the potential positive impacts on public health in marginalized communities near ports or industrial areas.
“It has as much importance as climate change because the cost of health that is due to exposure to pollutants is a major problem,” he said.