About 45 years ago, my grandfather wrote me a letter describing his idea for using hydrogen as a source of clean energy. I tried to explain the Second Law of Thermodynamics – creating the hydrogen by hydrolysis would cost more energy that he would get from burning it. Hydrogen fuel is only commercially viable if the source of energy is free (or at least very cheap).
Hydrogen is one of the cleanest, least problematic sources of energy. No emissions except water. No pesky radioactive waste.
2 H2 + O2 → 2 H2O (plus energy)
**Why It’s Time to Start Caring Much More About Clean Hydrogen**
**By Philip Verleger and David G. Victor, The New York Times, April 18, 2022**
**Hydrogen is a leading idea for cutting dependence on conventional fossil gas. Modern energy systems depend heavily on natural gas, in part because it is easy to store and use when needed. Greater use of gas has already helped cut emissions because it has displaced coal. Shifting to clean hydrogen could cut those emissions essentially to zero, and would also make it possible to reuse some of today’s extremely valuable gas infrastructure.**
**One way to make clean hydrogen is with electrolyzers that split hydrogen from water. Right now that’s expensive, but with a spurt of new investment, electrolyzer costs will likely tumble.** Ooh, there’s that pesky problem again! – W
**Other methods will compete as well...**
**Privately backed projects are exploring how to link hydrogen production to renewable electric power generators — a key innovation because hydrogen is easier to store than electricity and could help make electric grids reliable even when they depend on large amounts of intermittent wind and solar...** [end quote]
The consulting firm McKinsey estimates that the value of investment in clean hydrogen projects by 2030 will exceed half a trillion dollars, based on the announcements made — with Europe in the lead. That’s a really substantial amount.
Hydrogen is almost entirely supplied from fossil fuels by reacting methane with steam. 6% of global natural gas and 2% of global coal go to hydrogen production.
As a consequence, production of hydrogen is responsible for CO2 emissions of around 830 million tonnes of carbon dioxide per year, equivalent to the CO2 emissions of the United Kingdom and Indonesia combined.
Hydrogen can’t be considered a “clean” fuel unless it is generated by renewable energy (e.g. solar) rather than methane.
Most hydrogen is currently used in industrial production. With better available technology, hydrogen could replace natgas for power generation. It’s not practical for most automotive use because of the lack of widespread fueling stations.