Hydrogen is part of our future – let’s get started

Hydrogen can be a key component of the world’s goal of achieving net-zero greenhouse gas emissions by 2050. However, we must keep in mind what hydrogen is as we think about where it makes sense in our changing energy system.

Hydrogen is not a fuel like oil, coal, or natural gas. Instead, it is an energy carrier like electricity, made from other forms of energy. The advantage of hydrogen is that it has many of the useful properties of a fuel. It can be burned to produce high heat for industrial processes. Hydrogen can be stored and shipped via pipelines or ships, sometimes in the form of hydrogen carriers like ammonia since hydrogen molecules are tiny and difficult to handle. Hydrogen carriers have a higher energy density than electricity stored in a battery, making them suitable for long-distance transport like marine shipping. Hydrogen can serve as a decarbonisation pathway when certain properties of fossil fuels are necessary and other pathways don’t work or are prohibitively expensive.

Today, most hydrogen is made from natural gas, splitting the methane atom to produce hydrogen and carbon dioxide as a waste product. Future hopes for hydrogen lie in splitting water atoms using electrolysis instead, producing hydrogen along with oxygen instead of carbon dioxide. To be zero carbon, carbon dioxide associated with the process must be captured or electrolysis must use zero-carbon electricity.

The facts of zero-carbon hydrogen seem relatively straightforward, but the politics and understanding around developing the hydrogen economy are not. I’m frequently asked if hydrogen is the fuel of the future, and generally begin the discussion by stating that hydrogen isn’t even a fuel. In applications where electricity can be used directly, it should be. The extra step of transforming electricity into hydrogen makes no sense in such applications, since transformation always involves energy losses. (The laws of thermodynamics have not been repealed for the energy transition.) Hydrogen only makes sense when you need its special qualities and electricity won’t do.

Additional policy arguments centre about how to get the new industry off the ground. To be truly green, you want hydrogen produced via electrolysis to use carbon-free electricity all the time. But practically, such projects are unlikely to be paired directly with renewable projects and operate only when those projects are generating electricity. Running hydrogen generation that way would be prohibitively expensive and fail to take advantage of the fact that renewable energy works best when it is spread across geography; when it isn’t windy and sunny in one place, it may be in another. In the future, producing hydrogen from a zero-carbon grid makes sense, but how do we get from here to there? This argument is raging in both the United States and Europe.

Insisting on pairing renewable generation with hydrogen production on an hourly basis is likely to strangle the nascent clean hydrogen industry. To produce hydrogen efficiently at low cost, electrolysers need to run constantly, a constraint at odds with pairing them directly with intermittent renewable generation. For now, ensuring that enough new zero-carbon generation is added to the grid to cover demand from hydrogen production can help the industry get off the ground. This challenge is analogous to many businesses today that purchase credits for enough renewable power to cover their overall demand. These practices, both from hydrogen production and other businesses, increase demand for renewable power, a noble goal when the US grid is still 60% fossil-powered and the EU grid is at about 40% fossil.

This constraint should be tightened over time to ensure that green hydrogen is truly zero-carbon. Just as businesses are moving from procuring green power on an annual basis to 24-7 green power, the hydrogen industry must do the same as a greener grid makes such a policy possible. But in the meantime, we must not strangle a necessary industry by letting the perfect get in the way of the good.