Elon Musk has repeatedly—he claims about 8,000 times–dismissed the potential of hydrogen as a fuel, but his most famous quote is directed specifically at hydrogen fuel cells where he describes them as “mind-boggling stupid.”
The attractiveness of hydrogen as an automotive fuel from a global warming perspective is that it emits no carbon dioxide when used to generate electricity in a fuel cell.
The pro-hydrogen fuel camp likes to lead in with the fact that hydrogen is the most abundant element in the universe, but fail to mention this abundance consists of hydrogen atoms tied up in other molecules (as in hydrocarbons or water).
It is the hydrogen molecule (two hydrogen atoms bonded together) that is used as fuel and exists on Earth in only very small amounts. That means we have to manufacture it.
About 95% of hydrogen manufactured in the world is made by mixing natural gas with high-temperature high-pressure steam in a process called Steam Methane Reforming. This reaction gives off carbon dioxide, as does the heating of water with natural gas to make steam.
The total carbon dioxide generated and emitted to the atmosphere in this hydrogen manufacturing process is about the same as from the combustion of an amount of gasoline containing an equivalent amount of energy.
The hydrogen produced by the Steam Methane Reforming method is called grey hydrogen when the co-produced carbon dioxide is vented to the atmosphere, but when the carbon dioxide is captured and stored (no venting to the atmosphere) the product is called blue hydrogen.
There is also green hydrogen, which is made by another manufacturing process altogether called hydrolysis.
Electricity is used to split a water molecule into hydrogen and oxygen, but if the electricity is sourced from a fossil-fueled power generation plant, the goal of reducing carbon dioxide emissions is largely lost.
For green hydrogen to be a viable means of eliminating carbon dioxide emissions, it must use electricity from a non-greenhouse gas emitting source such as nuclear power.
This excludes hydroelectricity as it can produce as much greenhouse gases as coal-fired electricity due to the carbon dioxide emitted in the production of cement for the dams and the biogenic methane produced by the reservoirs.
The hydrogen fuel cell accomplishes the reverse of green hydrogen hydrolysis; it combines hydrogen and oxygen (from the air) to produce electricity and water.
The electricity is used to constantly charge a small battery which drives the vehicle’s electric motors. The fuel cell electric vehicle only eliminates carbon dioxide emissions when either blue or green hydrogen is used.
Up to this point, I don’t think Elon Musk really cares much. A Tesla, Musk’s battery-electric vehicle, differs primarily in that the electricity is not generated on the vehicle but is stored in a very large battery.
Likewise, the battery-electric vehicle only eliminates carbon dioxide emissions when the electricity used is from a non-carbon-dioxide-emitting power generation source.
It is after this point Mr. Musk is willing to say “8,000 times” that hydrogen fuel cells are mind-boggling stupid.
According to the US Department of Energy, when gasoline is burned in an internal combustion engine vehicle only 16% to 25% of the energy in the gasoline is used to rotate the vehicle wheels.
Most of the energy loss is within the internal combustion engine itself. In a hybrid gasoline-battery vehicle, that number range jumps to 24% to 38% of the energy being used at the wheels, primarily because of the vehicle’s electricity-generating braking technology.
In a Tesla, an amazing 86% to 90% of the energy stored in the battery goes to rotating the wheels, again taking into account the regenerative braking.
In a hydrogen fuel cell, only about one-half of the energy contained in the hydrogen is converted into electricity to be used at the wheels. That makes the battery-electric vehicle (Tesla) almost twice as energy-efficient as a fuel cell electric vehicle.
And it gets better for Musk. Electricity transmission losses from the power plant via wire to the charging station are about 5%.
Hydrogen is most efficiently transported by pipeline and is delivered into the vehicle’s storage tank at approximately 10,000 pounds per square inch. The pipeline and compression energy consumption required to do this is equivalent to about a 25% energy loss.
This makes a Tesla about three times more energy efficient. When green hydrogen is used in a fuel cell the electricity consumed in the hydrolysis reaction to make the green hydrogen contributes to another 30% energy loss and the amount of electricity used to turn the wheels drops to about 25% of the total input electricity.
That makes a Tesla almost four times as energy efficient as a fuel cell vehicle using green hydrogen, and the green hydrogen fuel cell vehicle has about the same overall energy efficiency as some gasoline engines driven the same distance.
That is the part that boggles Mr. Musk’s mind. Who would convert to a new electric vehicle that wastes between two-thirds and three-quarters of the input energy, similar to the existing system, when the Tesla energy loss is only about 10%?
But are hydrogen fuel cells stupid, Mr. Musk? No, because the fuel cell has three major advantages that may come into play for heavier vehicles used for hauling.
Fuel cell vehicles can be refueled with hydrogen much faster than recharging a battery. They can travel a further distance on a single tank of hydrogen than a battery vehicle can on a single charge.
And most importantly, they can be scaled up in size with less overall vehicle weight gain than a battery can.
What sometimes gets lost in the fuel cell versus battery electric vehicles debate is the objective is to eliminate greenhouse gas emissions.
Unless the hydrogen or electricity source is emissions-free, the greenhouse gases have then simply been moved from the tailpipe to the hydrogen plant or power plant.
That still may result in lower overall emissions and cleaner air above congested areas. But if the same amount of greenhouse gas emissions occurs, both fuel cell and battery-electric vehicles would be mind-boggling stupid.
Ron Barmby (www.ronaldbarmby.ca) is a Professional Engineer with a Bachelor’s and Master’s degree, whose 40+ year career in the energy sector has taken him to over 40 countries on five continents. He recently published “Sunlight on Climate Change: A Heretic’s Guide to Global Climate Hysteria” to explain in understandable terms the science of how both natural and human-caused global warming work.
Interesting article on ammonia (NH3) fuel cell technology. Easier to store and transport, more energy dense than gasoline, etc. “The supply vessel Viking Energy is being retrofitted with a 2-megawatt ammonia fuel-cell system.”
https://oilprice.com/Energy/Energy-General/New-Renewable-Fuel-Might-be-3-Times-More-Powerful-Than-Gasoline.html
Politicians & the non-technical need to understand that hydrogen and electricity are, like steam, not fuels (original energy sources), but merely means for storing and transmitting energy. What matters is the source of that energy.
CO2 absorbs only a small amount of IR across the spectrum emitted at ambient Earth temperatures.
Water vapour absorbs across a wide spectrum and is widely acknowledged as responsible for almost all of the so-called “greenhouse effect” !
Does it make any sense at all to curb emissions of an insignificant IR absorbing gas whilst promoting emissions of the “king of ’em all” ?
Finally climate “scientists” always tell us that 99+% of the atmosphere neither absorbs nor emits Infra-Red radiation. They also claim that 83% of the Infra-Red radiation Earth emits to space comes from the small percentage of “greenhouse gases” in the atmosphere.
This leads to 3 logical conclusions.
“Greenhouse gases” are not “heat trapping” gases – they are the principle emitting gases !
Nitrogen and Oxygen are the “heat trapping” gases – they may not absorb or emit Infra-Red radiation but only an idiot would deny they get heated substantially every day and cannot radiate that heat to space !
Just how does increasing the amount of the principle emitting gases – the so called “greenhouse gases” prevent more heat being radiated to space when they are supposedly the main source of said radiation and more must make more ?
The whole “back radiation greenhouse effect” is gobbledygook. None of the supposed supporting “facts” support it at all.
According to the article, in a fuel cell hydrogen vehicle a small battery is charged from the fuel cell and then that provides power to move the vehicle. This raises a question. Can the fuel cell provide enough power for a cross country trip at freeway speeds? I suspect the answer is no. The vehicle might rely on times when it is not being driven or when it is stop and go traffic to charge the battery. Does anyone know for sure?
In calculating the emissions of an electric vehicle or one that is using hydrogen made from electricity, nuclear and hydro electric power should not be counted. These energy sources are being used to full capacity and we are not building any more to accommodate electric or hydrogen vehicles. The extra capacity needed comes from more use of fossil fuels or new wind or solar power. Both wind and solar produce significant emission in building the capacity. There is no such thing as an emissions free vehicle.
David, If the hydrogen tank was big enough it would be able to sustain a fuel cell for a cross-country trip. However, weight begets weight and a bigger hydrogen tank would necessitate a bigger fuel cell, storage battery and electric motors. At some point it would not make any sense to increase the size of the hydrogen tank as the vehicle would be too heavy.
Now that this on page two it is not likely that anyone will see it but I’ll respond anyway.
Ron, you had a good answer but miss understood my question. It is reasonable to expect any type of vehicle to need to refuel, or recharge, on a long trip. My question was can the fuel cell produce enough energy to sustain freeway driving continuously, or does it need time of not moving to catch up on charging the battery.
David, my apologies. The literature I have read indicates that theoretically the fuel cell can run continuously at a high output to keep to the battery sufficiently charged. However I am not aware of any actual public domain road tests that prove that, so I am sorry I cannot offer a definitive answer. The California Hydrogen Business Council website might be a good place to look, as California has the largest fleet of operating hydrogen vehicles in the world. Best regards, Ron
Much of this article is predicated on the belief that CO2 emissions are bad, something that is highly unlikely. Now to tackle some issues the author ignores about hydrogen fuel cells. Start with the creation of H2–if it is from water where is this H2O coming from? To provide the amount of H2 needed it will take an immense quantity of water and places out west in the US and Canada there is a paucity of water that can be diverted to making H2.
The second issue he did not address is the highly flammable nature of H2. Certainly gasoline and diesel are flammable but hydrogen is exceedingly explosive and it is transported and stored at a very high pressure, something not needed for transporting gasoline or even natural gas.
I worked on our nuclear subs as a Reactor Operator and we had a hydrolysis plant onboard that we affectionately called “The Bomb” but instead of using it to make hydrogen but to make oxygen that was injected into our atmosphere so we could stay submerged. The hydrogen was bubbled out of the sub. So am familiar with the splitting of the H2O molecule using electricity (generated by the reactor).
Steve, I agree with your comments. The above article is a condensed version of one written for a paywalled newsletter, and in the original I address the safety, economic, and energy efficiency concerns of hydrogen. It simply could not all fit into this version. You can find the original at http://www.ronaldbarmby.ca under Current Writings (July01, 2021). Please also watch the videos under Presentations for my explanation of why CO2 is not a major driver of global warming. Climate Change Dispatch published a synopsis of my book on September 14, 2021, and that might interest you also. Best regards, Ron