> I am now more looking forward to seeing battery and energy storage solutions mature

I'm reading Bill Gates' latest book, he says he spent and lost a lot of money on battery tech and while we are able to get incremental improvements, it appears that an order of magnitude improvement is unlikely at this point.

Other areas are still possible - heck, batteries are still possible, but I'm not sure we should hope for that rather than draft an optimistic case of incremental improvements and start planning with that instead.

I think energy storage outside of chemical batteries is where infrastructure scale storage should be happening. Things like pumped dams or gravity batteries. Instead of thinking of them as longer term storage of excess energy, we can think of them as capacitors for the grid overnight. In this way while we still rely on a fossil fuel turbine as a last resort, the vast majority of the year can be covered by renewables.

Lets say the split looks like:

8am - 8pm : 100% renewables

8pm - 8am : Split between remaining renewables then gravity storage begins discharging

If you are going to run out of gravity storage, you will have ample warning, and you will have a comfortable amount of time to bring a backup gas turbine plant online. One of the big challenges with all grids is continuity and keeping everything in sync, most of the time the issue is not having the ability to rapidly respond to fluctuations in the grid. Gravity storage helps solve that issue by being very predictable, and (with a smart grid integration) instantaneously available.

Don't have time for a proper response, just a short note:

Yep people are looking into that, but it ain't trivial. Apparently one needs a fairly specific slope for it to be econom at the moment (competitive with chemical batteries). If you look on YouTube for the (clickbaity, unfortunately) title "the truth about pumped storage" (iirc), you should find a video from some engineering channel where some of this is mentioned. Another keyword might be Ireland. There's gotta be more information-dense / less time-consuming sources than that video though, it's just the one I got this from. My point being, if it were this simple, yeah. Looks like we'll (recurring theme) need a bit of everything to get there on the timescale we're looking at to avoid worse issues.

>I was also a big fan, but there are many alternatives now.

Do some research. There are essentially no alternatives to nuclear power for 100% carbon free generation. That's due to how power is produced, transported and consumed (in the US at least) and simply installing extra capacity of renewables so there's "extra power" won't work.

It's a big discussion, but I don't think we need 100% carbon free to the point of technicality. We should just jump on whatever is good enough and easily available right now, not in 10 years of commissioning time. The tech is here and now and it could be installed on your roof tonight. We should have rolled out nuclear 5 decades ago, and be reaping the rewards now.

In my state in Australia, which resembles California to a fairly uncanny degree in many areas, we have a majority of energy from rooftop solar for a period of most days, the rest is filled by gas generators and the whole shebang is stabalized by a massive tesla battery ( https://en.m.wikipedia.org/wiki/Hornsdale_Power_Reserve ). It isn't perfect but it is a huge decrease in carbon emissions and a big step toward totally renewable.

Somewhat ironically the state also has the national nuclear waste dump and was previously the site of British and American nuclear weapons testing out in the desert. So uh, guess we may as well have popped a reactor out there in the 60s and have enjoyed the clean energy.

You do some research. You're wrong. Your position might have been defensible ten years ago, but it's now obsolete.