“The argument of energy security for hydrogen doesn’t make much sense anymore,” says Daniel Simmons, deputy secretary of the energy ministry for energy efficiency and renewable energies. “But hydrogen has always been a very flexible fuel that can be made from a variety of sources, and this flexibility looks very attractive these days.”
Almost all of the hydrogen produced in the United States today is so-called “gray” hydrogen, which means it is made from fossil fuels such as natural gas. The rest is generated by electrolysis, in which water molecules are broken down into oxygen and hydrogen using electricity. Electrolysis can be climate neutral if the electricity is generated from renewable sources such as wind or sun. However, producing this green hydrogen is up to five times more expensive than producing gray hydrogen. “We really have to cut costs,”
Earlier this year, the Department of Energy announced $ 64 million in new funding as part of its H2 @ Scale program to support R&D in scalable green hydrogen projects. The DoE’s call for proposals highlighted six main research areas, including manufacturing techniques for hydrogen storage tanks and the development of fuel cells for heavy commercial vehicles. However, in terms of actual hydrogen production, the DoE mainly focuses on improving electrolysis technology.
“Electrolysers are already in use,” said Sunita Satyapal, director of the Department of Hydrogen and Fuel Cell Technologies at the US Department of Energy. “To cut costs, we also need to improve their efficiency because the bulk of the cost of hydrogen is electricity.”
According to Satyapal, the efficiency of electrolyzers is currently around 60 percent, but the DoE wants companies to find ways to increase it beyond 70 percent. At the same time, government officials want to double the average lifespan of electrolyzers to around 10 years of continuous use, which is necessary to ensure that they are inexpensive to use with gray hydrogen and natural gas. DoE officials may see electrolysis as the quick way to scale hydrogen production, but are also investing in other ways, including waste hydrogen technologies. Last year, the agency donated $ 1 million to Oregon State University researchers to develop a reactor that uses microbes to produce hydrogen from biomass, such as food scraps and wood chips.
“Waste-to-hydrogen approaches would be regionally specific and would be limited by the content and amount of the available waste raw material,” says Simmons. “This is in contrast to electrolysis, where the main raw material is water, which is more commonly available. Nevertheless, there are interesting regional options for using waste streams. “
Not everyone is convinced that waste hydrogen solutions can make a significant contribution to scaling green hydrogen production in the United States. Thomas Koch Blank, industry and heavy traffic analyst at Rocky Mountain Institute, a non-profit research organization for clean energy, says that problems with waste availability could be a major obstacle. He points to Sweden and Norway, two countries that have invested heavily in waste incineration systems and quickly faced garbage shortages as the demand for garbage exceeded supply. Today, both countries import their waste from other parts of Europe to supply their waste energy systems.
“I’m not saying it’s a bad idea,” says Koch. “It is good to use our waste streams productively for secondary purposes. However, I find it difficult to see that this source is really relevant to hydrogen scaling in the big scheme of things. “
Neither Kindler nor Mintzer claim that their waste-to-hydrogen systems will be enough to meet the growing demand for hydrogen alone. Instead, they see it as a technology that can work with other hydrogen production technologies while helping the United States to deal with increasing waste problems. “We urgently need more hydrogen and at the same time we have to get rid of the garbage that accumulates,” says Kindler. “Waste to hydrogen is a path that complements hydrogen production through electrolysis. Every hydrogen production solution must coexist. “
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