We are inching closer to an emission-free hydrogen-based future.
By the end of the year a 20 megawatt (MW) electrolyzer that runs on hydropower is expected to be up and running in Canada where it will produce on the order of 3,000 tons of hydrogen every year.
There’s a lot of unpack here, so let’s have a closer look.
Hydrogen is the most abundant element in the universe. That’s the good news. The bad news is that it almost always comes attached to something else. We know it most familiarly when two hydrogen atoms hook up with one atom of oxygen to form water (chemical formula H2O).
That “H” shows up in many other common forms such as methane (one carbon atom and four hydrogen atoms: CH4), bituminous coal (C137H97O9NS) and even table sugar (C12H22O11).
Hydrogen also has the highest energy content by weight of all known fuels—around three times higher than gasoline—and has long been used as a critical feedstock for the chemicals industry, including for liquid fuels.
The trouble is that it takes energy to separate hydrogen from whatever else it is attached to. (Read “Will hydrogen ever be more than the future’s greatest fuel?“.)
Hydrogen can be produced from diverse domestic resources, including fossil fuels, nuclear energy, and renewables (hydro, wind, solar, geothermal, biomass, and waste, including plastics).
The primary processes for producing hydrogen include thermochemical processes (such as reforming, gasification and pyrolysis) and through electrolysis via water splitting.
One big drawback with thermochemical methods is that carbon emissions result. By contrast, renewable energy resources such as wind, solar and hydro can power electrolysis and result in a virtually emission-free source of “green” hydro.
Colleagues who write the Electrifying blog identify three factors that they say are critical to contributing to hydrogen’s overall viability: (i) the initial capital expenditure for the electrolyzer, (ii) the cost of input electricity to be used for the process, and (iii) the base load (number of operating hours per year). They note that with the costs of wind energy and solar PV energy having fallen over the past decade or so, green hydrogen production is more economically feasible than ever, as input energy costs play a significant role in its production.
The U.S. Energy Department weighed in on hydrogen’s future in a report issued in mid-November. It said the primary demand for hydrogen today is as a chemical feedstock in petroleum refining and ammonia production. Around 10 million metric tons (MMT) of hydrogen are currently produced in the U.S. each year for these end uses. Most of the production comes from natural gas.
By the middle of the century, DOE estimates that production could rise to as much as 41 MMT with the largest share of that (on the order of 17 MMT) devoted to transportation uses. At present, hydrogen makes up a negligible amount of transportation fuel.
Given the focus that the outgoing administration has had on fossil fuels, it’s not surprising to see the DOE report tout both natural gas and coal as primary sources for hydrogen production. The report points out that natural gas and coal can be used with carbon capture to produce hydrogen “with no carbon dioxide emissions.”
To be sure, carbon capture and sequestration methods are available, but they are expensive and energy intensive in their own way. What’s more, coal mining and natural gas production present additional environmental costs that need to be accounted for.
With all that as background, let’s get back to the Air Liquide facility in Canada. Engine maker Cummins is supplying the electrolyzer, which will use surplus renewable hydroelectricity to generate green hydrogen. The electrolyzer technology is a relatively new addition for the engine maker, which a year ago bought a manufacturer called Hydrogenics.
Cummins estimates that the current cost of hydrogen produced from natural gas is somewhere between $1.50 to $2 per kilogram. It says that can power about 60 miles of travel for a hydrogen fuel cell passenger car. Green hydrogen, by contrast, costs around $5 to $6 per kilogram to send that same family the similar distance down the road.
The engine maker may be better known for the power trains it produces for big rigs. Last year, Cummins rolled out a demonstration Class 8 truck truck designed for 90 kW hydrogen-based fuel cells. The fuel cells are scalable in 30 kW or 45 kW increments up to 180 kW. The fuel cell truck also has a 100 kW lithium-ion battery capacity with a range of 150 – 250 miles between filling up.
The engine maker admits that without subsidies fuel cell vehicles are not cost competitive. That may well change in the next 10 years as technology advancements take place.
In yet another Canadian application, hydrogen produced during periods of excess renewable generation will be injected into an existing network of natural gas pipelines to boost the renewable energy content. People living the Toronto suburb of Markham will be the first to receive the blended natural gas.
“Small quantities of hydrogen can be manageable in existing natural gas pipeline networks,” according to a press release issued by energy company Enbridge and Hydrogenics. The venture also plans to deploy utility-scale facilities to produce green hydrogen, store it and then combust it at a later time for electric power generation.
The Canadian ventures are the latest steps in a widening effort to develop and deploy green hydrogen as a source of energy for industrial processes and large-scale electric power generation. For more on those topics, read this and this.
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The illustration is of an Air Liquide hydrogen facility in Denmark.