HOUSTON — In the five days of CERAWeek by S&P Global, participants raised questions about hydrogen as an energy source, including in trucking, mostly over the enormous challenges to build infrastructure for a hydrogen-fueled future.
But the environmental movement checked in here as well, represented by the Environmental Defense Fund. The EDF has generally been considered one of the more moderate environmental organizations, often working with companies rather than reflexively opposing them. And it has found itself criticized by other parts of the green movement for its politics.
EDF’s message on hydrogen can be pretty much summed up as “let’s slow down a bit.”
“We need to move from the hype and enthusiasm to a very realistic look to understand where hydrogen is really well suited, where it is likely to be used and places where we’re not sure,” Steve Hamburg, EDF’s chief scientist said in an interview with FreightWaves at CERAWeek.
“It’s like any energy system,” Hamburg said. “It has complications and it has unintended consequences, and there is a lack of data on which to differentiate between those things that meet the goals and those that don’t.”
EDF’s founder, Fred Krupp, sounded a more pessimistic theme in a Wall Street Journal opinion piece earlier this year. Its foreboding title: “Hydrogen isn’t as green as it looks.”
While Hamburg was more ambiguous about the environmental benefit of hydrogen, his primary reason for being at CERAWeek was the question of leakage.
Hydrogen is not a greenhouse gas, Hamburg said. But he called it a “potent indirect greenhouse gas” which reacts with other components in the atmosphere to generate gases that can be accurately labeled GHG.
Hydrogen also can create a set of chemical reactions to produce ozone in the lower atmosphere, and can react to produce water vapor, which acts as a GHG, Hamburg said.
“So these collective effects are not from hydrogen itself, but it does cause climate impact,” he added.
Research on those hydrogen-related reactions is 20 years old, Hamburg said, but the impact of a shift toward more hydrogen usage on climate change as a whole has not been fully studied.
The environmental benefits of hydrogen were mostly viewed as a given across the many hydrogen-themed panels at CERAWeek. The optimism mostly rests on the model of green hydrogen, where renewables — and in some definitions, nuclear power — are used to extract hydrogen from water. Those molecules are then used to power a variety of applications, be they industrial like cement manufacture or transportation like heavy-duty or even lighter-duty trucks.
Hamburg expressed skepticism about the value of hydrogen in certain applications. Taking a green electron produced from something like wind and then converting the electron into hydrogen “is costing you energy” in the transition process, he said. “So there is an energy penalty to converting your electron into hydrogen,” he said. The preference, he added, is using that green electron directly if possible.
For mobility, that would mean putting those electrons directly into a battery electric vehicle (BEV), because the conversion process to hydrogen is not necessary and is costly when its efficiency and GHG impact is measured. “You’re going to have more rapid decarbonization that way than if you go through hydrogen,” Hamburg said, because the process to turn those green electrons into hydrogen reduces the efficiency of the power generated by the green generation process.
Given that “we only have a certain amount of green electrons,” Hamburg said the best applications might be places where they can be used directly. He cited heat pumps along with BEVs as examples.
The issue as Hamburg sees it is one of “additionality.” He defined that as ensuring that the “energy source you are using to produce the hydrogen wouldn’t otherwise be available,” so it is “additional” to what energy sources exist already. “So you are not diverting the electrons away from a higher and better use,” Hamburg said.
In his article for The Wall Street Journal, Krupp gave a similar argument about hydrogen usage.
“Hydrogen is most appropriate in activities such as steel and cement production, for which there are no better alternatives, or as feedstock for advanced low-carbon fuels for ships and planes,” Krupp wrote. “But it makes no sense to divert renewable energy to make hydrogen for use in cars or homes, where electricity can be used directly instead. And since transporting hydrogen likely increases leakage risk, it’s better to produce it close to where it’s used.”
But although Krupp’s failure to mention heavy-duty trucking as a potential area for hydrogen usage could be seen as disapproval of that path, Hamburg was less certain. While light-duty vehicles would work better than direct green electrons stored and drawn from a battery, “as you move to the heavier transport it becomes harder,” Hamburg said. “Where that line is, we’re still figuring it out. It is not clear what segment of the transport sector should be handled by hydrogen.”
EDF set up a booth at CERAWeek in conjunction with Aerodyne Research, which has created in conjunction with EDF what Hamburg said is the “first fast-response, high-precision hydrogen monitor.”
According to Hamburg, data on hydrogen leakage is close to nonexistent. But the Aerodyne system is designed to bring the first model to market, he said, having gone through testing in the past few months at Colorado State University.
EDF over the years has stood out among other environmental organizations in that rather than simply opposing fossil fuels and further exploration for them, it focused for several years on the question of methane leakage, particularly from the exploding production levels of shale oil and shale gas. Based on Hamburg’s statements and the work with Aerodyne, the EDF clearly intends to have the same role in hydrogen.
Aerodyne and EDF’s plans are to “go out and measure real value chains,” Hamburg said, likening it to similar programs the group undertook for methane leakage more than 10 years ago. “We have the equipment to start making the measurements and bring it online this year,” he added.
As Hamburg noted, hydrogen molecules are the smallest among the elements. Given that, EDF is concerned that leakage from hydrogen production and distribution systems may not be airtight enough to prevent those unintended emissions.
Measuring hydrogen leakage might differ significantly depending on the usage in a heavy-duty vehicle, Hamburg said (though he repeatedly noted the lack of data at this point). For example, fueling a vehicle with hydrogen that then is processed in a fuel cell to provide electricity might be better protected against leakage, because of the fewer connections than a hydrogen internal combustion engine where welds and other connecting joints create a lot more places where hydrogen might leak.
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