[jessaustin]

Natural gas will stick around until utility scale batteries ramp up...

Batteries have improved over time, but I'm not convinced that they'll see the vast improvements necessary in order for them to replace natural gas for a long time. If natural gas really must be replaced the most logical alternative might be ammonia.

Ammonia has hydrogen's good properties: not a greenhouse gas, doesn't cause smog, numerous production methods including electrolysis, easily transported in liquid form, can be used in fuel cells or in ICEs. However it doesn't embrittle, in liquid form it's actually denser in hydrogen atoms than liquid hydrogen is, and due to its agricultural applications there is already an established distribution infrastructure (in the Midwest, at least).

[toomuchtodo]

I bet you $1000 to a charity of your choice that utility scale batteries combined with renewables replace natural gas for electricity generation in the US in the next 10 years. I shall even assume all the risk. If I'm correct, you can buy me a coffee.

[jessaustin]

Hahaha well tentatively let's say EFF...

Rhetorical flourishes aside, I'd love for you to be right and I'm perfectly content to be convinced that you are. What specific technologies or materials will get batteries over this hump? Please don't say lithium-ion because although they seem OK for phones I can't seem to buy one for a power tool that will last a year.

[DannoHung]

Are physical potential energy storage systems completely impractical?

Flywheels, compressed air, gravity storage?

[afarrell]

Of those, I believe only gravity storage (at facilities like Blenheim-Gilboa) are currently in use.

[jerven]

Flywheels are as well. But at a much smaller scale than gravity storage.

[afarrell]

Oh I wasn't aware. Link?

[jerven]

http://beaconpower.com/operating-plants/ but there are others, some even quite old. More often selected for niche reasons than market peak load balancing. e.g. site one at long end line of insufficient frequency stability.