The climate nutters pushing Hyrdrogen need a physics lesson

Carbon intensity of hydrogen from most sources is worse than coal, oil or natural gas

Data on the amount of CO2 released per kilogram of each fossil fuel are ubiquitous - Coal produces 2.42 Kg of CO2 per Kg of coal burned; Natural gas produces 2.75 Kg CO2 per Kg of gas burned; and, one Kg of oil produces 2.5 Kg of CO2 per Kg of oil equivalent (which includes other hydrocarbon liquids).

But climate nutters are all over hydrogen as the “fuel of the future” and the first hydrogren powered vehicles are already in service to catch this wave. “Green Energy” promoters produce gorgeous charts showing at what price hydrogen would be competitive with fossil fuels (I note the chart does not include any information on the assumed price of oil for the comparison but assumes a US$100 per ton carbon tax, a useless idea that will not make a dent in fossil fuel use).

The same source is kind enough to show the CO2 intensity of hydrogen by process, again using kilograms of CO2 but in this case per kilogram of hydrogen. For all sources except nuclear, solar and oil sands, hydrogen has higher emissions than coal, oil or natural gas. Nuclear is opposed by the climate nutters just as aggressively as they promote renewables. It is not until you get to the bottom four entries on the chart where there is any case for hydrogen if lower emissions are the goal. It is a pretty stupid goal in any event, since CO2 emissions are demonstrably harmless.

There is a weak case for hydrogen produced by solar or nuclear to be competitive with fossil fuels. But it is a stretch to call hydrogen competitive.

Using solar to generate electricity for electrolysis of water to create hydrogen (called White Hydrogen) makes that electricity unavailable to power EV’s or for home lighting or heating, for industrial use, or for any other place where electricity is needed. The conversion process suffers from entropy like all conversion processes, so the amount of electric power needed to create the hydrogen will exceed the energy inherent in that electricity and the combustion of the hydrogen to power a motor will similarly suffer from conversion inefficiency. The question is this - if you start with electricity from any source (including solar) and put it through two conversion processes to power a vehicle will the entropy loss be less than using the same electricity to power the electric motor in an EV? I don’t know the answer, but I am doubtful since combustion processes typically have higher entropy than electromagnetic based on my fading memory of physics. Thermal methods like gasification, steam methane, reforming, and pyrolysis face similar obstacles.

Maybe one day hydrogen will have a place in transportation but the odds aren’t that good. Volvo has begun testing of trucks running on hydrogen powered fuel cells but my understanding from an industry contact of mine is that the benefits have yet to be demonstrated. As a kid, I had an idea for a hydrogen powered vehicle where the hydrogen was burned, the resulting water captured and the water converted back into hydrogen and oxygen through electrolysis using the output of the engine and to provide the electricity for the electrolysis. It was my hoped for “perpetual motion machine” and failed owing to the concept that I later learned in university called “entropy”. Basically, every conversion process has a natural loss of energy and the degree of loss is “entropy”. It seems simple but the more conversion processes involved, the greater the loss. For those not familiar with the term, here is a link that explains entropy in terms of the degree of disorder in a system. It is a foundational concept in thermodynamics and chemistry, along with other sciences.

The data on the carbon intensity of hydrogen produced using coal as fuel for the process is illustrative. Hydrogen from that source is twenty times more carbon dioxide intensive than coal itself. Twenty times! The difference is the energy lost producing hydrogen from coal manifesting itself in more coal needed to produce the amount of hydrogen sufficient to replace the coal itself as a fuel. Give that some thought. In rough numbers, the entropy in that process is 95% yet all it is doing is using coal to produce electricity (a relatively efficient process in widespread use) and then using that electricity to power electrolysis of water to produce the hydrogen (an inefficient process by any measure). You have to really want hydrogen to squander 95 of the energy in coal to get there.

If hydrogen succeeds as a fuel, which I see as unlikely, it will be based on the emergence of demonstrated economic advantages and not an argument for lower CO2 emissions or one that depends on a carbon tax or a subsidy. CO2 emissions are harmless and fossil fuels are cheap, reliable and widely available. You just can’t make a silk purse out of a sow’s ear.