As mentioned in the last post, my new energy storage report, The Energy Storage Conundrum, mostly deals with issues that have previously been discussed on this blog; but the Report goes into considerable further detail on some of them.
One issue where the Report contains much additional detail is the issue of hydrogen as an alternative to batteries as the medium of energy storage. For examples of previous discussion on this blog of hydrogen as the medium of storage to back up an electrical grid see, for example, “The Idiot’s Answer To Global Warming: Hydrogen” from August 12, 2021, and “Hydrogen Is Unlikely Ever To Be A Viable Solution To The Energy Storage Conundrum” from June 13, 2022.
At first blush, hydrogen may seem to offer the obvious solution to the most difficult issues of energy storage for backing up intermittent renewable generation. In particular, the seasonal patterns of generation from wind and sun require a storage solution that can receive excess power production gradually for months in a row, and then discharge the stored energy over the course of as long as a year. No existing battery technology can do anything like that, largely because most of the stored energy will simply dissipate if it is left in a battery for a year before being called upon. But if you can make hydrogen from some source, you can store it somewhere for a year or even longer without significant loss. Problem solved!
Well, there must be some problem with hydrogen, or otherwise people would already be using it extensively. And indeed, the problems with hydrogen, while different from those of battery storage, are nevertheless equivalently huge. Mostly, to produce large amounts of hydrogen without generating the very greenhouse gas emissions you are seeking to avoid, turns out to be enormously costly. And then, once you have the hydrogen, distributing it and handling it are very challenging.
Unlike, say, oxygen or nitrogen, which are ubiquitous as free gases in the atmosphere, there is almost no free hydrogen available for the taking. It is all bound up either in hydrocarbons (aka fossil fuels — coal, oil and natural gas), carbohydrates (aka plants and animals), or water. To obtain free hydrogen, it must be separated from one or another of these substances by the input of energy. The easiest and cheapest way to get free hydrogen is to separate it from the carbon in natural gas. This is commonly done by a process called “steam reformation,” which leads to the carbon from the natural gas getting emitted into the atmosphere in the form of CO2. In other words, obtaining hydrogen from natural gas by the inexpensive process of steam reformation offers no benefits in terms of carbon emissions over just burning the natural gas. So, if you insist on getting free hydrogen without carbon emissions, you are going to have to get it from water by a process of electrolysis. Hydrogen obtained from water by electrolysis is known by environmental cognoscenti as “green hydrogen,” because of the avoidance of carbon emissions. Unfortunately, the electrolysis process requires a very large input of energy.
How much is it going to cost to produce green hydrogen as the storage medium for a mainly wind/solar grid? My Report first notes that as of today there is almost no production of this green hydrogen thing:
To date, there has been almost no commercial production of green hydrogen, because electrolysis is much more expensive than steam reformation of natural gas, and is therefore uneconomic without government subsidy. The JP Morgan Asset Management 2022 Annual Energy Paper states that ‘Current green hydrogen production is negligible…’
So we don’t have any large functioning projects from which we can get figures for how expensive green hydrogen is going to be. In the absence of that, I thought to undertake an exercise to calculate how much capacity of solar panels it would take to produce 288 MW of firm power for some jurisdiction, where the panels could either provide electricity directly to the consumers or alternatively produce hydrogen by electrolysis that could be stored and then burned in a power plant to produce electricity. (The 288 MW figure was selected because GE produces a turbine for natural gas power plants with this capacity, and says that it can convert the turbine for use of hydrogen as the fuel.). Here is that exercise as written up in my Report:
Consider a jurisdiction with steady electricity demand of 288 MW. . . . The electricity needs of our jurisdiction can be fully supplied by burning natural gas in the plant. But now suppose we want to use solar panels to provide the electricity and/or hydrogen for the plant sufficient to supply the 288 MW firm throughout the year. What capacity of solar panels must we build? Here is a calculation:
• Over the course of the year, the jurisdiction will use 288 MW × 8760 hours = 2,522,880 MWh of electricity.
• We start by building 288 MW of solar panels. We will assume that the solar panels produce at a 20% capacity factor over the course of a year. (Very sunny places such as the California desert may approach a 25% capacity factor from solar panels, but cloudy places such as the Eastern US and all of Europe get far less than 20% of capacity; in the UK, typical annualised solar capacity factors are under 15%). That means that the 288 MW of solar panels will only produce 288 × 8760 × 0.2 = 504,576 MWh in a year.
• Therefore, in addition to the 288MW of solar panels directly producing electricity, we need additional solar panels to produce hydrogen to burn in the power plant sufficient to generate the remaining 2,018,304 MWh.
• At 80% efficiency in the electrolysis process, it takes 49.3 kWh of electricity to produce 1 kilogram of hydrogen. GE says that its 288 MW plant will burn 22,400 kilograms of hydrogen per hour to produce the full capacity. Therefore, it takes 49.3 × 22,400 = 1,104,320 kWh, or approximately 1,104 MWh of electricity to obtain the hydrogen to run the plant for one hour. For the 1,104 MWh of electricity input, we get back 288 MWh of electricity output from the GE plant.
• Due to the 20% capacity factor of the solar panels, we will need to run the plant for 8760 × 0.8 = 7008 hours during the year. That means that we need solar panels sufficient to produce 7008 × 1104 = 7,736,832 MWh of electricity.
• Again because of the 20% capacity factor, to generate the 7,736,832MWh of electricity using solar panels, we will need panels with capacity to produce five times that much, or 38,684,160 MWh. Dividing by 8760 hours in a year, we will need solar panels with capacity of 4,416 MW to generate the hydrogen that we need for backup.
• Plus the 288MW of solar panels that we began with. So the total capacity of solar panels we will need to provide the 288MW firm power using green hydrogen as backup is 4,704 MW.
Or in other words, to use natural gas, you just need the 288 MW plant to provide 288 MW of firm power throughout the year. But to use solar panels plus green hydrogen backup, you need the same 288MW plant to burn the hydrogen, plus more than 16 times that much, or 4,704 MW of capacity of solar panels, to provide electricity directly and to generate sufficient hydrogen for the backup.
That calculation assumed a 20% capacity factor of production from the solar panels over the course of a year. It turns out that actual solar capacity factors are more like 10-13% for Germany, 10-11% for the UK, and about 12.6% in New York. (California, with few clouds, gets capacity factors somewhat in excess of 25%.). Doing the same series of calculations using a 10% capacity factor for the solar panels, you will need something like 9,936 MW of solar panels to provide your 288 MW of firm power for the year, with the green hydrogen as your storage medium.
In other words, you will need about 35 times the capacity of solar panels as the amount of firm power that you are committed to provide. The reasons for the vast differential include: the sun doesn’t shine fully half the time; most of the time when the sun does shine it is low in the sky; places like the UK, Germany and New York are cloudy more often than not; and there are significant losses of energy both in electrolyzing the water and then again in burning the hydrogen.
Anyone and everyone should feel free to check my arithmetic here. I’m fully capable of making mistakes. However, several people have already checked this.
My Report then takes a stab at translating the enormous incremental capital cost of all these solar panels into a very rough cost comparison of trying to generate the 288 MW of firm power from solar panels and green hydrogen versus simply burning natural gas in the plant. I got cost figures for the turbine plant and the solar panels from a March 2022 report of the U.S. Energy Information Agency. Using that data:
[T]he cost of the 288MW General Electric turbine power plant [would be] around $305 million, and the cost of the 4,704 MW of solar panels [would be] around $6.25 billion.
If you needed the 9,936 MW of solar panels because you live in a cloudy area, the $6.25 billion would become about $13 billion.
My very rough calculation in the Report, with the 20% solar capacity factor assumption, is that electricity from solar panels plus green hydrogen storage would start at somewhere in the range of 5 to 10 times more expensive than electricity from just burning the natural gas. At the 10% solar capacity factor assumption, make that 10 to 20 times more expensive.
And after all of this we still haven’t gotten to the very substantial additional engineering challenges of working with the very light, explosive hydrogen gas. A few examples from the Report:
- Making enough green hydrogen to power the world means electrolysing the ocean. Fresh water is of limited supply, and is particularly scarce in the best places for solar power, namely deserts. When you electrolyse the ocean, you electrolyse not only the water, but also the salt, which then creates large amounts of highly toxic chlorine, which must be neutralised and disposed of. Alternatively, you can desalinise the seawater prior to electrolysis, which would require yet additional input of energy. There are people working on solving these problems, but solutions are far off and could be very costly.
- Hydrogen is only about 30% as energy dense by volume as natural gas. This means that it takes about three times the pipeline capacity to transport the same energy content of hydrogen as of natural gas. Alternatively, you can compress the hydrogen, but that would also be an additional and potentially large cost.
- Hydrogen is much more difficult to transport and handle than natural gas. Use of the existing natural gas pipeline infrastructure for hydrogen is very problematic, because many existing gas pipelines are made of steel, and hydrogen causes steel to crack. The subsequent leaks can lead to explosions.
It’s no wonder that green hydrogen is all talk.
But…but… we’re going to need all the green hydrogen to transform transportation to carbon-free energy – especially air, rail and trucks. We’re going to need billions of acres of solar and millions of wind turbines just to make hydrogen. By the way, to carry around quantities of hydrogen equivalent to tanks of diesel requires massively heavy tanks that can safely hold 3,000-10,000 psi (200-700 bar). To carry the equivalent hydrogen energy of a 747 would probably require a fuel tank weighing more than a 747.
At least this article mentions the issue of water use. Here in Alberta people freak out at the relative small amount of fresh water used in fracking and to generate steam for SAGD and other oil/sand separation processes. For example the Fort Mac area operations are only allowed to take 2% of the annual flow of the Athabasca.
And it’s the end of the world.
With the transportation issues with hydrogen it’s going to have to be produced close to the electricity generation plants that will use it and that means far from the oceans in most cases.
The amount of water needed for this will be magnitudes greater than the O&G industry uses today.
But that is just waved away , of course.
The other alternative is the UK’s CCC idea of making hydrogen at floating offshore windfarms and piping it ashore. So start with very expensive electricity to feed a combined desalination and electrolysis plant on a floating platform and then a fragile pipeline to shore, easily attacked. Perhaps stop off halfway for some depleted gas field storage, give or take how much leaks out…
Rube Goldberg and Heath Robinson would I am sure have exulted in the craziness of it.
Did you ever notice…
Nobody ever talks about the need for backups for conventional power sources? Why do we want to destroy an electrical infrastructure that works for Rube Goldberg scheme that quite obviously doesn’t work?
Because art majors and gender studies majors are making technical policy.
We do of course have backups for conventional power sources. It’s just that you don’t need a lot given the opportunity for maintenance by rotation in low demand seasons and the general reliability of the plant. It is only at peak demand that the extra margin comes into play. The typical grid runs with average demand of about 60% of peak demand. Much of that difference is accounted by the diurnal fluctuations, but the seasonal element is usually of some significance as well.
The green H2 situation is significantly worse than depicted. You also have to store the hydrogen. Either cryogenically or by compression into tanks. The former wastes an additional 45% of electricity, the latter ‘only’ 15%. Both covered in essay ‘hydrogen hype’ in ebook Blowing Smoke.
The latest ideas concern the use of salt caverns. Suitable salt formations are not to be found everywhere, and the real performance of these for long term storage at the volumes required is an unknown.
Concerning the use of nuclear generated electricity for the production of green hydrogen and as load-following backup for wind and solar …..
The nuclear industry is promoting the oncoming small modular reactors as having significantly better load following capability than the current generation of reactors, thus making the SMRs a good fit inside a grid where wind and solar output varies considerably.
In addition, the SMRs are being promoted for use in supplying electricity for producing green hydrogen and for charging grid scale batteries during those periods when wind and solar are keeping up with instantaneous demand and the SMR’s output isn’t needed in real time for grid backup and stabilization.
Nuclear fuel represents about 10% of the cost of running a nuclear power plant. The other costs include capital cost amortization, operations, and maintenance. An enhanced load-following capability is very useful for an SMR to have. But when a nuclear plant isn’t generating at near full capacity, it isn’t recovering its costs unless it is either being subsidized or unless the unit price of the electricity that it does actually produce in real time sells at a high enough price.
In any case, using nuclear, wind, and solar for power generation is strictly a public policy decision. Relying on green hydrogen for energy storage, for transportation, and as a substitute for natural gas is strictly a public policy decision. In a truly competitive power market, neither nuclear nor solar nor wind could compete with gas-fired generation. In a truly competitive energy market as a whole, hydrogen would be a complete non-starter as a replacement for natural gas, for gasoline, and for diesel.
Were it not for government-mandated low and zero carbon requirements, no one would be thinking about new-build nuclear power, not here in the United States anyway. No one would be thinking about wind and solar backed by batteries. No one would be thinking about hydrogen as a substitute for natural gas, for gasoline, and for diesel.
Another issue is now emerging as a consequence of the general inflation America and the western world is now experiencing, and its impacts on the power generation equipment supply chain. Rumors are developing that the estimated capital costs of the new SMRs are increasing rapidly, adding more financial and project management risk to the difficult task of getting these new technologies rolled out and initially deployed on schedule and on budget.
Over the last thirty years since 1990, the inflation-adjusted capital costs of any large-scale industrial facility built in the United States have approximately doubled, and for a variety of reasons which are difficult to address either individually or collectively. If today’s inflation continues at its current pace, it’s not unreasonable to believe that by the end of this decade, the capital costs of any nuclear, wind, solar, or grid-scale battery project will have doubled yet again over today’s current estimates.
We have a perfect storm coming close on the horizon. President Biden and the climate activists in his administration are determined to shut down all of America’s coal-fired generation on an accelerated schedule. They haven’t got anything resembling a coherent and credible plan for replacing the shuttered capacity. And so the great bulk of the retired capacity will be permanently lost.
The numerous obstacles now standing in the way of replacing any substantial portion of the lost generation capacity are huge, and are getting worse with each passing year. All of us have no choice at this point but to adapt to a future world in which electricity costs two or three times what it costs today, and where we have to get by with two-thirds or even half of the electricity we use today in the year 2022.
Hydrogen at 10,000 psi still takes up a ton more room than batteries or gasoline.
The Houdini molecule will escape unless very expensive means are used.
The obvious best use and storage for hydrogen is in long hydrocarbon chains called….gasoline, diesel fuel, JP-1, kerosine, ect.. Hydrogen is too expensive (read inefficient) to produce because what do you do with the oxygen (with approximately 1/2 of the energy used) left over if sourcing from water or are you to use methane…that nasty fossil fuel. Why not just use methane for transportation fuel…better than hard to store hydrogen.
“When you electrolyse the ocean, you electrolyse not only the water, but also the salt, which then creates large amounts of highly toxic chlorine, which must be neutralised and disposed of.”
You must also create an equal quantity of sodium hydroxide (NaOH) which will neutralize the Cl.
I am not a chemist, but I suspect that Cl can be minimized by controlling the voltage at which the reactions occur.
The ocean is quite big as a diluent for any HCl you might make. Plans to use the oceans actually require an element of desalination as a pre-treatment, which eats into the process efficiency. Read about the Dutch PosHYdon project here:
https://hydrogentechworld.com/offshore-hydrogen-production-enables-far-offshore-wind-deployment
It’s only tiny of course, but the engineering hurdles look to be considerable. It is not going to be cheap hydrogen at GW scale. Diluting a small amount of hydrogen into the hydrocarbons pumped ashore from a field which is not in the first flush of life is not going to test the resilience of piping hydrogen ashore in quantity.
These two statements from the article seem to have a numerical contradiction:
“Very sunny places such as the California desert may approach a 25% capacity factor”
and …
“California, with few clouds, gets capacity factors somewhat in excess of 25%“
A brief scan of the “California” link suggests the 1st statement might better say “… may approach a 30% …”.
Ric
Great article…
Except you do some amazing calculations regarding “capital costs”.
Total capital costs include the cost of land and buildings.
You calculations might include structures, but I seriously doubt they include the cost of land.
A regular reason for excluding the capital cost of land is because land is priced differently, literally every where.
Still, California, Utah or Nevada desert gets pricy when near habitable locations.
Worse, land in New York State or England is far pricier.
Soar installation calculations should always include the total acreage required. Commercial pricing for a few locations would also help.
Thank you!
I think the energy needed to transport and store the gas needs to be taken into account. That will also consume a large portion of the energy in the hydrogen, or need additional solar panel installation.
I do not lose sleep at night over energy. The solution to the energy “crisis” is the use of abundant available energy for which we have only a little R&D remaining. That may be nuclear power (small modular nuclear reactor), hot-dry geothermal, solar panels in orbit free of atmospheric attenuation, gas hydrates, whatever we are willing to do. There is no shortage of available energy, unless we limit ourselves as we are.
With abundant cheap energy, we would not be sweating the cost of hydrogen fuel cells, which is the most logical successor to gasoline, that is, given a market incentive, gasoline stations would have no problem adding a hydrogen UST and dispenser pump to their gas pumps which would result in a gradual phasing out of gasoline according to supply and market forces.
As soon as energy shortages hit college campuses, there will be effective action. We should therefore encourage ineffective action such as the use of wind and solar on college campuses until they wake up. College campuses and state capitals should be the first to feel the coming blackouts. SNMRs use less than critical mass in their reactor cores, solving one safety issue. But I’m thinking that we didn’t have GIS in the 1970s when the existing plants were built. Department of Energy could use GIS to build a national model of optimal siting locations for SNMR. Near water (but not too near), far from people, far from natural hazards, close to electric grids, away from critical habitat, etc. Tell the GIS what is desirable in a location and undesirable and it will figure it out.
Hydrogen fuel is an enemy for cost warriors, for now. Grid electricity would need to be $0.05 per kwh to make it worthwhile. My bill ranges from $0.10 to $0.15 per kwh. This region gets a lot of power from hydro, geothermal, combined cycle natural gas, a little from Diablo Canyon reactor, etc. So we aren’t that far off. It’s not completely out of reach. Nearby SMUD rates (Sacramento) go up to $0.32 per kwh. It is beyond reach for them.
I see it as entirely possible but requires determination and good engineering (or market forces).
PG&E was going to shut down Diablo Canyon. After closing San Onofre and Rancho Seco, the State of California actually stepped in and stopped the shutdown of Diablo Canyon, preserving 10 to15% of the State’s power. There is hope.
As I understand it the most serious problem with aging nuclear reactors is pipe corrosion. Not a corrosion engineer but somehow that doesn’t seem that hard to fix. Viewing it like a homeowner, we bought an old home with cheap plastic or galvanized plumbing. It will be expensive to replace it with HDPE or copper, but one replacement should last a long time, improving the unit cost. Drains that are cast-iron pipe can be replaced with ABS for a cost. Big initial expense, then it will last a long time. So replace the pipes in old reactors with corrosion-resistant pipes. Cheaper than a new reactor … or no reactor.