Up to this point, I don’t think Elon Musk really cares much. The Tesla, his battery electric vehicle, differs primarily in that the electricity is not generated on the vehicle but it is stored in a very large battery. Neither the fuel cell electric vehicle nor the battery electric vehicle emits any pollutant exhaust, which results in cleaner air above our cities. The battery electric vehicle only contributes to a reduction in 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 in 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 Elon. 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 the 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 the Tesla four times as energy efficient as a fuel cell vehicle using green hydrogen, and the green hydrogen fuel cell vehicle about the same overall energy efficiency as a gasoline engine driven the same distance.
That is the part that boggles Mr. Musk’s mind. Who would convert to a new system that wastes between two thirds and three quarters of the input energy, similar to the existing system? If you turn that equation around it means that to drive the same distance the fuel cell electric vehicle requires between three and four times the input energy of a battery electric vehicle. Then multiply that energy wastage by five million Canadian vehicles and the target of the Strategy is met. It only makes sense if the real strategy was to find a new market for existing or planned hydroelectric excess capacity to make green hydrogen. One should also factor in that while hydroelectricity may not emit carbon dioxide, the hydroelectric reservoirs emit a much more potent greenhouse gas in unmeasured but significant quantities: biogenic methane (which I examined in last month’s article).
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 refuelled 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. These three factors make the hydrogen fuel cell much more favorable in heavy long-haul transport applications. In a Canadian context the fuel cell may prove to be more operable in severe cold weather.
To get to the stupid level assigned by Musk we have turn our attention to the use of hydrogen as a replacement or supplement to natural gas, which is the second part of the Strategy. It envisions that slightly under one third of the total carbon dioxide emission reductions from using hydrogen as a fuel will come from blending hydrogen into natural gas and displacing 50% of the natural gas we now use for heating in industry and buildings. The Strategy does recognize that required modest adjustments to existing natural gas pipelines and end-use burners restrict the blend to 20% hydrogen by volume. The Strategy fails to mention that above 20% hydrogen by volume creates significant leakage concerns in plastic pipes in confined spaces (as in your basement) and a wider range of ignition conditions (more likely to explode if it leaks into your basement). The Strategy also fails to mention that under the right conditions, hydrogen combustion can produce nitrogen oxides which are hazardous to human health and react with sunlight to cause smog.
What also has not been recognized is that at the same temperature and pressure, the energy equivalent of hydrogen gas takes up three times the space of natural gas. In order to replace 50% by volume of the natural gas in a pipeline with the energy equivalent in hydrogen, the volume of hydrogen added would be three times the volume of the natural gas removed. The result is an original one cubic foot of natural gas has been replaced with its energy equivalent of a blend that takes up two cubic feet. Not only are the existing pipelines too small to carry twice the volume, but if you exceed a 20% hydrogen content in that volume things might start blowing up, literally.
Blending 50/50 is a serious safety risk. The only way to displace 50% of the natural gas used in Canada today for industrial and building heat with hydrogen is to build a second transcontinental pipeline system dedicated to hydrogen and convert the end-use burners to hydrogen specific appliances. The hydrogen blending strategy amounts to this:
- Convert cheap natural gas to expensive blue hydrogen with carbon capture and storage; this conversion triples the cost of the energy. (I elected to rule out very expensive green hydrogen as direct electric heating would then make more sense.)
- Then duplicate the existing transcontinental natural gas pipeline system with one for hydrogen-only. (This would be no small matter in a country where the Federal Government’s signature legislation, Bill C-69, is dubbed the No More Pipelines Bill. Could we even find enough pipeline protestors?)
- Switch 50% of the end users to pure hydrogen (and be prepared to discuss increased health and safety risks without mentioning the name Hindenburg).
Even the Federal Government must realize this is quite impossible. It may be a proposal ostensibly to promote hydrogen, but it could result in a conversion from cheap, abundant, carbon dioxide-emitting natural gas directly to expensive, overbuilt, methane-emitting hydroelectricity.
That leaves us with the final component of the Strategy, which would contribute slightly more than one third of all carbon dioxide emission reductions by 2050. Large industries such as oil refining, fertilizer production and steel making already use significant quantities of pure hydrogen in their industrial processes. Currently most of this is grey hydrogen supplied by the steam methane reforming process without carbon capture and storage. The Strategy states that grey hydrogen should be upgraded to blue hydrogen. This is a case of the Federal Government double-dipping on carbon capture and storage initiatives already under review in most provinces and under provincial jurisdiction.
The Hydrogen Strategy for Canada is flawed because it selects the least efficient transportation option, proposes an unviable heating option, and claims credit for an industrial option that has already been initiated. Bad economics are not a barrier, or even a speed bump, and safety considerations are unmentioned. I think Elon Musk’s “mind-boggling stupid” comment sums it up well.