Melbourne Trains

@WaterWaiver @AllNewTypeFace There's a perception that we could just reuse existing methane gas (i.e. "natural gas") infrastructure for hydrogen. But often that just isn't the case:

"The pipelines that transport hydrogen are made of the same basic material as most of those built for natural gas: steel. But hydrogen is a much smaller molecule than methane, the main component in natural gas. In fact, hydrogen is the smallest molecule on Earth. Its size means it can squeeze into tiny spaces in certain steel alloys in a way that natural gas cannot. That can cause “embrittlement,” making the metal more likely to crack or corrode. Hydrogen molecules are also much more likely to leak from valves, seals, and other connection points on pipelines (which risks undermining green hydrogen’s climate benefits). And hydrogen is transported in a more pressurized state than natural gas, which puts more stress on the pipeline carrying it.

"Rather than transporting 100 percent hydrogen, many companies are now testing whether they can blend hydrogen with natural gas for transport in existing pipelines. In a study released last summer, the California Public Utility Commission found that up to 5 percent hydrogen blended with natural gas appears safe, but higher percentages could lead to embrittlement or a greater chance of pipeline leaks. Internationally, France places the highest cap on hydrogen blending, at 6 percent, according to the International Energy Agency (Germany allows blending at 8 percent under certain conditions)."

Source: https://climate.mit.edu/ask-mit/can-we-use-pipelines-and-power-plants-we-have-now-transport-and-burn-hydrogen-or-do-we-need

If the aim is to reach net zero emissions by 2050, a 90% or 95% methane to 10% or 5% hydrogen gas blend just isn't that useful for reaching that goal.

(And that's assuming the hydrogen is green hydrogen as well.)

And if a lot of your infrastructure has to be retrofitted anyway, electrification plus renewables plus storage makes a lot more sense in many cases.

There are still use cases where green hydrogen will be useful — international long-haul flights, rockets, some industrial processes, etc. But it's not the best solution in most cases.

#ClimateChange #hydrogen #gas #NetZero #electrification #transport