08 March 2023

If Hydrogen The Way To Go? Probably Not.

One possible path for our energy future would be to make wider use of hydrogen. Is hydrogen the way to go?

Probably not.

There is lots to like about about hydrogen based energy, which is one of the best options for chemical energy storage. Hydrogen fuel cells have the highest energy density of any chemical way to store energy: 2.6 times as much as natural gas and 3 times as much as gasoline. Fuel cells also emit nothing other than water vapor when used. 

But issues related to the supply and distribution of hydrogen fuel make it problematic.

Hydrogen Fuel Supply Issues

But the main way commercial hydrogen is produced now is to chemically strip it from fossil fuel hydrocarbons like natural gas, which is inefficient and shares a lot of the problems involved in using fossil fuels in the first place:
Synthesis gas—a mixture of hydrogen, carbon monoxide, and a small amount of carbon dioxide—is created by reacting natural gas with high-temperature steam. The carbon monoxide is reacted with water to produce additional hydrogen. This method is the cheapest, most efficient, and most common. Natural gas reforming using steam accounts for the majority of hydrogen produced in the United States annually.

A synthesis gas can also be created by reacting coal or biomass with high-temperature steam and oxygen in a pressurized gasifier. This converts the coal or biomass into gaseous components—a process called gasification. The resulting synthesis gas contains hydrogen and carbon monoxide, which is reacted with steam to separate the hydrogen. . . .  
Today, almost all the hydrogen produced in the United States is used for refining petroleum, treating metals, producing fertilizer, and processing foods. The primary challenge for hydrogen production is reducing the cost of production technologies to make the resulting hydrogen cost competitive with conventional transportation fuels.
Scientists are making progress in finding more efficient ways to produce hydrogen from the electrolysis of water with advanced catalysts to the reaction and other tricks, although adding a major new user to our limited fresh water supply has its own problems.  But we aren't there yet. 

Hydrogen Fuel Distribution Issues

Of course, even once we get good systems in place to produce usable hydrogen, we have to build a refueling network from scratch that competes in the alt-fuel market with electrical chargers (powered with existing national electrical grids) in a national electrical vehicle charging system, that is already well on its way to being built out.  According to an article from December 22, 2022 in Automotive World magazine:
This year marks an important anniversary in electric vehicle (EV) technology: the tenth anniversary of the first supercharger station opened by Tesla in Los Angeles in September 2012. Although, a decade has passed, the availability of quick and convenient charging is still cause for concern for many prospective customers. According to the US Department of Energy’s Alternative Fuels Data Center, there are currently 46,000 public EV charging stations in the US, with more than 13,000 of them in California. However, thousands more are needed to respond to the increase in EV demand and the industry’s shift away from internal combustion engine (ICE) cars. . . . 

The current charging infrastructure is not nearly in the state it needs to be to support the projections of 50% of all cars being EVs in the next ten years, but . . . charging station infrastructure is a work-in-progress across the globe. . . .

In Europe, there are currently about 400,000 fast charging stations compared to 47,000 in the US. The EU has committed to increasing that number to one million by 2025. In the US, the government has proposed federal minimum standards of at least four public charging ports every 50 miles along a highway with the goal of 500,000 charging stations across the country by 2030. . . . 

Despite the barriers of charging and range anxiety . . . EVs have gained massive momentum in recent years: “In 2019 EVs and hybrid vehicles were just 6% of vehicles produced (five million), but production in 2022 has tripled and is now at 18% of global passenger car production, forecasted to rise to 25% in 2023. We expect to see more than 20 million EVs produced in 2023.

Hydrogen vehicle production is stuck in a Catch-22. Hydrogen refueling networks respond to demand from customers who have hydrogen fueled vehicles, but a lack of a refueling network discourages people from buying hydrogen vehicles. Yet, almost all of the current alt-fuel vehicle momentum in R&D, charging station networks, and legislation to support it has been devoted to electric vehicles. It would be very difficult to turn this momentum around even if one can make a technological case that hydrogen fuel cell vehicles are better than electric vehicles.

One of the main reasons the internal combustion engine initially surged to market dominance over electric cars which were neck and neck with each other in the nineteen teens was that at the time only big cities had electrical power grids which gasoline powered cars didn't need. This made gasoline powered cars more attractive to consumers everywhere but big cities and people who needed to engage in intercity traffic. So gasoline powered cars had an almost 100% market share of the "horseless carriage" market, and as a result, these engines had received years of technological refinement, while electric vehicle battery technology was neglected, by the time that small towns finally had electrical grids which could have been used to refuel electric cars.

Even if hydrogen for hydrogen fuel cells can be produced at a competitive price and they are otherwise solid on the technological merits, overcoming the nation's lack of a hydrogen refueling network could be fatal to its widespread adoption as an energy source for vehicles. 

Nuclear Fusion Power Using Hydrogen

Of course, the other way to use hydrogen to produce energy is in nuclear fusion power plants. 

The heavy hydrogen (i.e. deuterium and tritium) fuel supply issues for nuclear fusion plants would be a trivial part of the cost of nuclear fusion power. This is so even though it costs much more to produce heavy hydrogen than ordinary hydrogen, because you first have to separate out heavy water from ordinary water and then you have to used electrolysis to extract the heavy hydrogen from the heavy water.

The heavy hydrogen fuel costs are trivial because you need about four million times less hydrogen to produce the same amount of energy from a kilogram of hydrogen in a hydrogen fuel cell, when you are using the hydrogen in nuclear fuel, despite the fact that no other chemical reaction based energy source has as much energy density as hydrogen fuel cells. 

Nuclear fusion generates 580,000,000 Mj of energy from a kilogram of hydrogen. In contrast, hydrogen fuel cell produces 142 Mj/kg. Natural gas (i.e. basically methane) produces 54 Mj/kg and gasoline produces 46 Mj/kg. 

Realistically, we are at least five or ten years out from being able to produce net energy at a commercial scale with sustained nuclear fusion plants. 

More importantly, nuclear fusion only makes sense to produce on a commercial scale if it is similar in price per Mj to the alternatives, even with significant subsidies to recognize the environmental benefits of nuclear fusion over anything but renewable energy 

We are probably at least twenty years out or more from being able to commercially produce nuclear fusion power at a price that is competitive with the alternatives like nuclear fission from uranium and plutonium, thorium decay, natural gas, syngas made from coal, and non-chemical fuel renewables like wind, solar, hydropower, tidal power, and geothermal. 

Previous posts at this blog supporting this conclusion and detailing the progress being made with nuclear fusion power technology can be found in posts from January 3, 2022 (China sets a new record in sustaining nuclear fusion reactions), October 26, 2021 (breakthroughs in turning heat into energy more efficient, which incidentally have continued to be made since then), and October 8, 2021 (reviewing the economic and technological barriers to commercial scale nuclear fusion power plants). 

The bottom line from those posts is that a nuclear fusion process needs to generate 18 times as much energy as is injected into it, not just net positive energy generation, to be viable commercially due to energy losses in getting the energy produced to the end user. But, improved efficiency in turning heat into electricity with new technologies could ease that requirement somewhat.

Also, you need to bring the cost of building a 1000 megawatt nuclear fusion power plant down to about $18.6 billion or less to make nuclear fusion a viable commercial power source. The current estimate of the likely cost of building a plant like that if it could be done, however, is about $3 billion, so this is less of a constraint than the technological barriers to nuclear fusion based power generation.

6 comments:

Guy said...

The "logical alternative" of liquid synthetic fuel made by combining CO2 from carbon capture and H2 from electrolysis will probably slay the H2 economy. The advantages of carbon neutral liquid fuel are immense. It's almost like the infrastructure to distribute it already exists. Recent papers (that I can't find today!) imply a cost of about $150/bbl for a pilot plant at 2023 levels of development.

andrew said...

@Guy

The economic price is in the ball park of $25-$40/bbl

Tom Bridgeland said...

My daughter is working in a grad program at a Japanese university on this topic right now. She has a couple of papers out. Sadly, I remain a skeptic. Their proposals call for the mass construction of breeder reactors over the next 50 years to supply the electricity to make this work. I pointed out that virtually the entire left stridently opposes nuclear energy without which the hydrogen economy can never take off.

I do believe hydrogen does have some valuable niche possibilities. Ocean transport, for one. Cargo ships currently run on the lowest grades of fuel oil, filthy stuff and highly polluting. Point sources of hydrogen located in major ports might be fairly simple to create, eliminating many of the distribution problems.

andrew said...

"My daughter is working in a grad program at a Japanese university on this topic right now. She has a couple of papers out."

That's awesome.

"Their proposals call for the mass construction of breeder reactors over the next 50 years to supply the electricity to make this work."

Hard to see a lot of benefits to this vis-a-vis other kinds of electrical energy storage ("batteries" in the broad sense which is really what hydrogen fuel cells are as well) outside niches where the extra energy density of hydrogen is valuable since you need long ranges away from refueling/recharging -- ships, ground vehicles in remote locations, airships, etc.

"Point sources of hydrogen located in major ports might be fairly simple to create, eliminating many of the distribution problems."

Great idea, and honestly, while ocean going freighters are big enough to have nuclear power plants and it is a proven concept in the U.S. Navy, the Russian Navy, and the Russian merchant marine, given the resurgence of piracy and the temptation it would present to a country trying to gain access to nuclear materials, the risks seem to great. I'm also a fan of sail power as a partial power supply for freighters.

The port source is particular on point if they can figure out how to extract hydrogen from sea water without desalinization which is a technology reaching "shit or get off the pot" stage now.

"I pointed out that virtually the entire left stridently opposes nuclear energy"

The science driven leftists like me are pro-nuclear energy. And, given that scientists (even nuclear physicists) are overwhelmingly left of center, the left's cooperation is needed to advance nuclear energy.

Tom Bridgeland said...

As I said, 'virtually' the entire left opposes nuclear energy. People like you, science-driven leftists, are an absolutely tiny minority in a sea of anti-science leftism. The greens outnumber and out-shout and out-spend you, not just in the US but world-wide.

There is no chance whatsoever that the left will back mass production of nuclear power plants on the scale needed to move to a hydrogen economy. Building a singe nuc plant has been impossible in the US since now many decades?

andrew said...

Authorization for the biggest wave of new nukes since the 1960s and 1970s in the U.S. came in a Democratic administration. The establishment Dems are a lot less anti-nuclear than you'd think, even though they make less noise.