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Comment by testfoobar | Hacker News Reader

In the US, use of residential natural gas has stayed nearly constant for decades. Natural gas use for electricity generation on the other hand has nearly gone up by 4 times in the past 40 years:

https://www.eia.gov/energyexplained/natural-gas/use-of-natur...

Restricting or eliminating home usage of natural gas seems identical in its relative ineffectiveness as restricting home water use while ignoring large agricultural users.

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Actually it makes a lot more sense than may appear at first glance.

Heat pumps are incredibly efficient. So much so that burning natural gas to generate electricity to power a heat pump is more efficient than burning the gas directly to create heat.

So even if we were to discount renewables entirely and change all natural gas furnaces to heat pumped powered by natural gas on the grid, we'd still come out ahead.

These are very different because of the end goal. A world where we don't drive our food and eventually ourselves extinct is a world with vastly less gas use, to the point where the uses you highlighted (both electricity generation and home heating) are both eliminated entirely while I assure you we're not going to stop using water. We need to change how it's assigned, who gets access and to how much, but we're not going to eliminate it.

So then the question is, if we're eliminating all gas usage, why do A before B rather than B before A and the answer to that is very simple. Electricity is fungible, and it's much harder to change all the millions of individual home and small business installations, so you should begin with that first or you'll never get done.

This makes all of zero sense, especially for a forum populated by engineer-types who are familiar with turning abstract ideas into tangible and highly scalable applications.

A subset of users who use a ton in % terms, and can be targeted cleanly and clearly to change use, translates into a large % decrease with the minimal amount of work.

You are suggesting a waterfall-style approach. Toil for years because it’s harder?

If we want to get rid of all gas furnaces within 20 years, we have to start now if we want to do it the cheapest way. Furnaces have a 20 year lifespan, so if we install any more gas furnaces in the future, we'll have to rip them out before end of life. Instead, whenever a furnace needs replacement, put in a heat exchanger.

Gas generators OTOH have a 50 year lifespan. They'll have to be ripped out prematurely.

Modern Gas turbines can run on Hydrogen, and/or blends of Hydrogen and Methane.

So they dont need ripped out, just better fuels.

You might have to replace the combustor.

And all of the valves, inspect all of the welds, et cetera. Hydrogen leaks through everything. Just ask NASA why SLS hasn't launched yet.

Industry around the world manipulates 70 million tonnes of hydrogen a year, so I think they have this valve thing figured out.

That's not very much, about 0.1% of natgas consumption. And the vast majority is used immediately upon production and not transported or stored.

But yes, there are lots of good hydrogen valves out there. Old natgas valves aren't good hydrogen valves.

You're proving the parent's point. Electricity is fungible so it will be easier to replace natural gas used for electricity than the millions of homes heated by it.

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