Around the world, more and more hydrogen microgrids are cropping up.
For example, Gov. Kathy Hochul wants New York to become a green hydrogen hub and wants fuel cell microgrids — which use green hydrogen — to help it achieve this goal.
NTPC, the largest utility in India, planned to construct the nation’s first stand-alone fuel cell microgrid that uses green hydrogen at its guest house in Simhadri, a village near Visakhapatnam in southern India. The goal is to deploy multiple microgrids in various off-grid and strategic locations throughout India.
And the well-known Stone Edge Farm in California’s wine country uses hydrogen in its microgrid, along with other sources of clean energy.
Taking hydrogen use to a new level, now hydrogen microgrids are being developed that produce electricity to help manufacture hydrogen gas and provide fuel for trucks that run on green hydrogen.
California hydrogen highway
This could be a double win for the planet, said Don Turner, COO, H2 Energy Group, which is based in Austin, Texas and plans a “hydrogen highway” between southern California and Oregon along Interstate 5.
H2 Energy Group’s project calls for two microgrids to be up and running next year in southern California.
“We were only going to build a hydrogen fuel microgrid. Then we saw that we could produce electricity more cheaply than the grid,” said Turner. And that electricity would be cleaner than grid power.
One microgrid feeds the other
The first microgrid, based on hydrogen and clean energy, will produce 5 MW of electricity that will power the second microgrid, which will produce 10,000 kilograms of hydrogen per day.
Because the microgrids will be located in California, where grid power is pricey, it will be less expensive to use microgrid power than to obtain electricity from the grid, said Turner. Grid power in California is generally 9.5 cents/kWh to 18 cents/kWh, while creating hydrogen-based electricity in a microgrid costs about 12.5 cents kwh, he said.
He’s not the only one to find that hydrogen-based electricity in California is at par with or less expensive than the grid.
Ways2H, which uses waste as a feedstock from which to extract hydrogen, found that in some regions of the country — especially California — the company can produce hydrogen that matches electricity prices on the grid, at a price of 8 to 10 cents/kWh.
H2 Energy Group, which is financing the Hydrogen Highway project with the help of investors, plans to create five hydrogen filling stations along the highway, hopefully at existing gasoline stations. But they’re encountering competition from owners of electric-vehicle charging stations who want to use the sites. If needed, H2 Energy Group could build its own stations, said Turner.
One of the main goals of the effort is to eliminate the release of carbon dioxide by big trucks. An 18-wheel truck fueled by diesel emits about 4.4 pounds of carbon dioxide per mile, or 240 tons a year, said Turner.
A typical truck will travel 100 miles with 7 kilograms of hydrogen fuel, he said.
Uses pyrolysis not electrolysis
Hydrogen is often created using electrolysis, which is energy intensive. But H2 Energy Group chose a less-known approach — pyrolysis — and says it will be less expensive than other options and will emit no carbon.
With pyrolysis, woody biomass is put in boilers, where the heat separates carbon and hydrogen. The material undergoes a post processing step that yields 99.5 % pure hydrogen. The process is carbon negative, said Turner.
Electrolysis, on the other hand, involves using electricity to split water into hydrogen and oxygen. Electrolyzers can be small units, the size of household appliances, or large central facilities tied to renewable or other clean forms of electricity production, according to the U.S. Department of Energy.
The DOE noted that electrolysis can yield zero greenhouse gas emissions, but the electricity used must be based on clean resources.
Learn more about microgrid innovations at Microgrid 2022: Microgrids as Climate Heroes in Philadelphia, Pennsylvania June 1-2.
Estimates of cost savings
Pyrolysis is 30% to 50% of the cost of electrolysis-generated hydrogen on a dollar per kilogram basis, according to Turner.
Based on a price of $25 a ton for biomass, the cost of producing hydrogen using pyrolysis is $1.85 per kilogram, said Turner. For electrolysis, the cost is $5 to $9 per kilogram, depending on the cost of electricity, he said.
H2 Energy also chose to use pyrolysis because the company can use woody biomass to create hydrogen, yielding a carbon-free process. The company plans on using trees as biomass, either by acquiring downed trees from federal government lands or building its own plantation.
Turner said that the company can acquire enough biomass to ensure the microgrids operate 24/7, even after disasters such as earthquakes. The company has relationships that allow it to buy biomass, he said.
“We will always have a 30 days’ supply of feedstock. Over time, we will have our own plantation where we will grow our own wood,” he said. For each tree harvested, H2 Energy will plant a new tree to ensure its work is carbon neutral. The company also wants to use downed logs and trees on federal lands, saying removing the woody debris will help prevent forest fires.
Build it and they will come
Not all trucks are equipped to utilize hydrogen gas, said Chris Hedrick, founder and executive chairman of H2 Energy Group. More truck manufacturers would build hydrogen trucks if the infrastructure were available, he added. H2 Energy Group’s project aims to help solve that chicken-or-egg problem by providing infrastructure for fueling with hydrogen gas. In the meantime, the company will supply hydrogen gas to one manufacturer, Hyzon Motors, which produces zero-emission, hydrogen-powered commercial vehicles that utilize fuel cell technology.
Meanwhile, the H2 Energy project is expected to yield a bonus: The pyrolysis process will produce a byproduct called biochar, charcoal created by heating biomass without oxygen. It’s basically pure carbon.
When fed to cows, it reduces flatulence and, along with it, emissions into the atmosphere of polluting methane.
“When you feed it to cattle, it makes them healthier and reduces the amount of methane they emit,” said Turner.
If Turner is right, make that a triple win for the planet.
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