- The first thing to know is that while hydrogen is energy-dense by mass, it isn’t energy-dense by volume.
- Different gases, different temperatures are required for liquification.
- That means that just the cost of the liquified hydrogen, excluding the energy costs of liquification or getting it into the ship, would be 1.9 times as high as the delivered price of LNG.
An old employer with whom I worked in Canada and Brazil recently contacted me with a question about a Wall Street Journal article he’d seen about a proposed Namibia project to create green hydrogen and send it to industrialised countries. He was unsure if this was financially feasible. Of course, it isn’t, but it provided me with an excuse to finally do the math as reported by Clean Technica.
LNG
Liquid natural gas (LNG) is the best comparison, as it requires liquification, which consumes about 10% of the amount of energy embodied in the LNG and oceanic shipping.
Those 266,000 cubic meters amounted to about $29 million in value before the recent spikes.
The first thing to know is that while hydrogen is energy-dense by mass, it isn’t energy-dense by volume.
Different gases, different temperatures are required for liquification.
This is because even liquified, hydrogen has less energy by volume than LNG, but also because liquifying hydrogen takes about 33% of the energy in the liquified hydrogen, as opposed to the 10% required for LNG. Different gases, different temperatures are required for liquification. Amazing stuff with liquid oxygen for space travel, but not so much anywhere less exacting.
Liquified hydrogen
The second problem is that hydrogen by itself is expensive.
These numbers are as likely as unicorns appearing worldwide and granting free rides to children.
A cubic meter of liquified hydrogen masses 71 kg.
That means that just the cost of the liquified hydrogen, excluding the energy costs of liquification or getting it into the ship, would be 1.9 times as high as the delivered price of LNG.
Currently, the average for trip durations, excluding loading and unloading periods, is around 23 days, and the pre-berthing, loading and unloading add another 4-5 days. Calling it 28 days results in an additional cost of $4.2 million.
Total costs
That brings the total costs of the delivered hydrogen to roughly $19 million for 27% of the delivered energy.
More realistic numbers from Lazard’s LCOE with still low $20/MWh electricity, still high 90% capacity factors, and more realistically priced but still cheap electrolyzers would be 40% more expensive, around 7x the price of LNG per unit of energy.
Doing the math with the numbers that most favour hydrogen shows how starkly bad the economics of using it for energy really are.
Of course, this is before the liquid hydrogen is converted to actually use energy, at a maximum of 60% efficiency, which is about the same as a well-combined cycle gas turbine.
What does all this mean for the actual sunshine falling in Namibia?
Well, take 20% off for electrolysis, 33% off for liquefication, 10% for efficiency losses for long-haul cooling and handling, and 40% off for conversion back into electricity, and solar energy in Namibia turns into perhaps 29% of the energy is useful.
Globally consumed
Of course, this doesn’t address the problem of distributing hydrogen in the country that imports it either, or the complete and utter lack of any large-scale hydrogen distribution network.
85% of hydrogen consumed globally is manufactured onsite because it’s so expensive to ship.
Of course, Namibia being in southern Africa next to South Africa, it would make more sense for it to deliver the electricity there instead.
Northern African solar, wind, and storage linked to fat HVDC pipes crossing the Strait of Gibraltar, crossing from Tunisia to Italy, and crossing the Bosphorus — as transmission lines already do today — makes much more economic sense.
Assuming the entire route is underwater, that would deliver about 88% of the generated electricity to market, not 29% — more than 3 times as much. Similarly, the Australian green hydrogen proposal originally ran HVDC transmission to Singapore, but has been distracted by the hydrogen hype and now proposes to manufacture hydrogen and ship it.
Shipping
Of course, there are even less efficient ways to ship hydrogen.
It could be converted into a liquid hydrocarbon with the addition of CO2 from somewhere and upgraded to a useful plug-compatible fuel, then shipped, at only multiples of the cost of just running things off of electricity, and with the added “benefit” of air pollution.
This isn’t to say that Namibian green hydrogen can’t be useful.
The country is dependent on South Africa for urea fertilizer and could be manufacturing that itself to supply the 9% of its economy dependent on agriculture.
Yet another straightforward analysis that accounts for both the physics, the engineering, and the costs makes it clear that hydrogen is not an economically viable store of energy for our future decarbonized economy.
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Source: Clean Technica
