From Manhattan Contrarian
Francis Menton
In New York, we have our own unique and special acronym for how we’re going to make the future a zero-emission grid dominated by wind and solar power. The acronym is DEFR – “Dispatchable Emission-Free Resources”. When the sun goes down and the wind dies down in the middle of winter, we crank up the DEFR to keep us warm and comfortable. Of course, there are zero carbon emissions because DEFR is, by definition, “zero emissions.”
Unfortunately, no one knows exactly what this DEFR is. There are only a few options. Nuclear energy works, but in New York it's completely stymied by regulatory hurdles and the certainty of decades of litigation. Batteries are very expensive and physically incapable of doing the job. This has led many green energy advocates to view hydrogen as a last resort. Granted, we haven't yet produced any meaningful hydrogen from carbon-free sources. But it seems simple: Just use wind and solar generators to run electrolyzers to make hydrogen from water; then store the hydrogen in some large caverns and burn it when needed. No carbon involved. Problem solved!
Over the past few years, I have published a number of posts commenting on the many issues that make this “green” hydrogen fantasy unfeasible. This June 2022 article states that the cost of making hydrogen from water is unlikely to be lower than or even close to the cost of extracting new natural gas from the ground; this August 2024 article discusses many other issues with hydrogen, such as its relationship to natural gas That compares to lower energy density and the potential need for entirely new infrastructure such as pipelines, power plants, delivery trucks and consumer appliances.
Now a new study has emerged focusing on different parts of the costs of using hydrogen as the economy's primary energy source. The problem is the cost of storing hydrogen from the time it is produced until it is needed. The new study was published on October 8 in the scientific journal Joule and is titled “Carbon Abatement Costs of Green Hydrogen in End-Use Sectors.” (This link only leads to the lengthy introduction and summary. You'll have to pay $35 to get the full article, but the introduction at the link will tell you what you need to know.)
Perhaps the most important thing about this new study is the authors. They are Roxana Shafiee and Daniel Schrag, both at Harvard and with impeccable climate cult credentials, including at various Harvard sub-schools and institutes (Center for the Environment at Harvard University, Department of Earth and Planetary Sciences at Harvard University, Paulson School at Harvard University) holds multiple positions. These people cannot be dismissed as “climate deniers”.
Shafee and Schrager correctly recognize that the cost of producing hydrogen from water is only a fraction, and likely only a fraction, of the cost of delivering useful hydrogen to consumers. They criticize green hydrogen enthusiasts for not paying enough attention to other costs, especially “storage and distribution” costs:
Hydrogen produced by electrolysis using renewable energy sources (green hydrogen) is gaining attention as a potential strategy for decarbonizing hard-to-abate sectors of the economy where electrification is technically challenging or prohibitively expensive. Many governments have set policy targets and, in some cases, financial incentives for green hydrogen production, and production costs are expected to fall rapidly over the coming decades, providing low-cost carbon reduction opportunities for many industries. However, Many recent analyzes do not consider the storage and distribution costs of delivering green hydrogen to different sectors, or how these costs vary based on end use.
So Shafei and Schrager set out to correct these flaws. To its credit, S&S found that the cost of distribution and storage infrastructure depends largely on how intensively the infrastructure is used. (As far as I know, thousands of people in New York's vast energy regulatory agency haven't figured out this simple principle yet.) The more cycles of storage, the less expensive it is per unit of stored energy then used. S&S notes that some industries, notably those such as petrochemicals and steel, can cycle hydrogen storage multiple times per month, thereby reducing costs. Unfortunately, this does not apply to the power industry:
Although the cost of hydrogen storage and distribution can be reduced (<$1/kgH2) through economies of scale, this requires high utilization of storage and distribution infrastructure, which is not applicable to all end-use sectors. If storage and distribution infrastructure is underutilized, costs can increase significantly. If storage is cycled less than 10 times per year, for example where demand changes seasonally (eg for heating or power generation), salt cavern storage costs will increase on average from less than $0.50/kgH2 to $6/kgH2.
That’s right: Hydrogen produced and stored to heat homes can only be recycled no more than once a year. To understand the significance of the costs quoted, remember that the energy equivalent conversion factor from $/kgH2 to $/MMBTU (the unit in which natural gas prices are commonly quoted) is 8. This is only the storage capacity during the year. Meanwhile, Henry Hub natural gas is currently priced at $3.06/MMBTU, much of which does not need to be stored for long periods of time as it can be produced roughly as needed to meet demand.
S&S therefore deserves credit for identifying hydrogen storage costs as a significant and unrecognized issue. But unfortunately, they only considered storage during the year. If green hydrogen is to become a backup to a grid powered primarily by wind and solar, there's also the huge problem of years of storage. In an article on September 28, 2023, I described a then-just-released report from the Royal Society on long-term energy storage to support wind and solar generators. Some 37 years of UK weather data collected by the Royal Society show that the most severe wind and solar “droughts”, similar to rain droughts, may only occur every 20 years or more. Storage solutions to support wind and solar generation without fossil fuel backup are needed to cope with these worst-case drought conditions.
The Royal Society report includes the following chart showing how much money might need to be drawn from storage to deal with these worst-case drought scenarios:
This graph shows that fully half of the storage required for a complete backup over a 37-year data period will be called only twice, and about a quarter will be called only once. Maybe S&S should go back to their laptops and figure out how much it costs per unit of energy stored in salt caverns that are only used every 37 years. If the storage cost for one cycle per year is $6/kgH2, would the storage cost for one cycle every 37 years be $222/kgH2? The blending cost between storage that is cycled annually and the rarely used fraction that is cycled every 10, 20 or even 37 years is about $100/kgH2, equivalent to $800/MMBTU of natural gas. This is more than 250 times the current price of natural gas, and of course this is just the storage cost. The cost of actually producing the hydrogen will be additional.
I understand that there is a push to build some hydrogen infrastructure, funded by government subsidies. It is almost impossible to imagine how much subsidies would be needed to make such a system fully functional. It will never happen.
Relevant
