Benefits of Green Hydrogen

Thanks for sharing, Barry. It seems like green hydrogen as a hyped product is really having a moment recently-- which is great, and I do want to see the potential for storing energy from renewable overgeneration, as a means of cleaning up industrial processes, etc.-- but it seems like there hasn't actually been a recent breakthrough in the technology, so I'm curious why 'all of a sudden' it's getting people even more excited? Are the economics shifting in a beneficial way? 

Barry, your riddle brought a smile to my face - a real accomplishment before coffee. Like Jumpin' Jack Flash, hydrogen is a "gas, gas, gas!" too, of course, and "hydrogen, hydrogen, hydrogen!" would be a mouthful.

There isn't much of a thermodynamic reason for using hydrogen as an energy storage medium, however. Like any chemical reaction, we only get back as much energy as we put into it. If electrolysis and fuel cells were perfectly efficient, we'd get back exactly the same amount of energy as that required to pull it apart from water.

But neither are very efficient, and the amount of progress it's possible to make in that regard is limited. Depending on variables, at least 90% of the energy invested in pulling hydrogen apart from H20 then converting it back to water is wasted. Storing electrical energy in batteries is nearly the opposite - with the best Li-ion grid systems, only 20% of energy is wasted. So if our goal is to try to overcome intermittency from solar and wind, we're getting far more energy back if we store it in batteries. But compared to massive storage tanks, batteries cost a fortune.

The most efficient way to power a grid is generating electricity in real time to match demand - by far - and that's impossible to do reliably with renewables. CNN host Fareed Zakaria calls that limitation the "Achilles' Heel" of solar and wind, which seems to be a particularly apt description.

Though venture capitalists are enamored with hydrogen, ask a physicist or chemical engineer about its potential - you'll likely get an eye roll. And curiously, most of its proponents seem to work for oil companies, raising the question: is green hydrogen another elusive "just around the corner" solution designed to ensure continuing dependence on natural gas? Before we invest any significant public money in hydrogen, whether green, brown, blue, or black, it's a question that demands an answer.