[mgfist]

You don't need to store that much energy. It's much more cost-efficient to over-provision energy sources. In a few decades we will see solar over-provisioned to 2-3x normal consumption and some battery and that will provide 100% uptime.

[u320]

The most cost-effective way is a combination of over-provisioning, batteries and hydrogen storage. The exact mix is determined by consumption patterns and local wind/solar conditions. Generally though it's extremely expensive to rely on over-provisioning+batteries alone in places with unreliable weather patterns.

Falling battery prices helps of course but we are very far from a point where we can eliminate the need for hydrogen.

[oblio]

You're overprovisioning at the wrong time with solar, though. What good is 2-3x the power output during the day when you're at 0 during the night? You'd still need 12h of storage or more realistically a mixed energy production setup.

[ncmncm]

There will be absolutely massive demand for H2, for myriad industrial processes, not limited to ammonia and hydrocarbon synthesis. So, whatever excess power you can generate will find a ready market with anybody equipped to bank H2. And, banking industrial quantities of H2 is cheap, whether you liquify and store in underground tanks, or pump into caverns under moderate pressure.

[u320]

Maybe in Arizona. In places where clouds is a thing you are looking at weeks of storage. And some of that stored energy would need to be collected months ahead of time. This is simply not doable with batteries, hydrogen storage is absolutely essential.

[oblio]

I think we're in agreement, maybe my phrasing was unclear :-)

My opinion is that we need a mix of energy sources and we need a mix of energy storage solutions.