[plasmatix]

But is it low enough?

Solar drops to zero every night.

For hydro, there's already seasonal variation with rain/snow melt. Beyond that, it looks like the majority of hydro in the US is on the west coast, which has been experiencing a drought for years and is projected to get worse. The west coast is big on removing dams for habitat restoration, too.

Wind: Admittedly I have no idea what sort of consistency wind has. But it does seem reasonable to assume the overall reliability of wind power will decrease as installed capacity increases, assuming we started with the most productive geographies first and then move to increasingly marginal areas.

In the same way that storm fronts travel through an area and bring high speed winds perhaps there is the opposite, where relatively sudden, large-scale lulls form?

To minimize the likelihood of blackouts we'd need to either:

1) Build sufficient excess capacity of wind/solar/hydro to overcome variance in output. This may not be feasible, if even possible, considering the points above.

2) Maintain fossil fuel peaker plants.

3) More nuclear for base load.

Having written these thoughts out I now realize your statement presumes we can ever (and always) meet 100% of electricity demand with wind/solar/hydro in the first place.

[poorlyknit]

Solar does not drop to zero every night if you connect enough countries to the west and the east or your country is big enough. And there's literally always wind because the ground heats up as the sun moves, creating imbalance in temperature and therefore air pressure.

There's enough countries out there that have been using renewables consistently for years (esp. EU countries). I don't understand how this is still a talking point. Daily variance in supply is equalized by trading energy with your neighbors which uses the phenomenon described above: The sun is always shining somewhere.

For Germany in particular it was a mistake to move away from nuclear before coal (imo lobbying is mostly at fault here) but they've been building renewables since the late nineties. It took them the time it takes to build a single nuclear reactor to move to more than 50% renewables and those are much easier (= cheaper) to maintain for the years to come.

[mpweiher]

None of this is true.

Solar definitely does drop to zero every night and no, we don't have the connectivity, or the land-mass, to have sunshine somewhere all the time. Russia does...but well, Russia.

There is not "literally always wind". And we've had several days of "Dunkelflaute" in Germany per year now, much higher than anyone predicted.

Renewable advocates like to average over time, so having too much energy at some point in time (which makes the energy worthless and prices go negative, as in "please stop feeding energy into the grid, it's harmful!!") and having too little at other times averages out. As my statistics professor used to joke: if your left leg is standing in liquid nitrogen and your right leg in boiling fat, you are enjoying a nearly perfect mean temperature. Variance matters.

And so the real world does not work the way renewable advocates would like, and no, we don't have nearly the storage to make that work, nor a credible way to create such storage at remotely affordable prices, never mind the horrific environmental impact of that much battery production.

> There's enough countries out there that have been using renewables consistently for years

Nope. One example that is frequently cited is Denmark, but they themselves say that this is only possible because they are a tiny country with lots of neighbours with reliable electricity supply from whom they can purchase when they need it. They also have more interconnect with those neighbouring countries than typical total demand. This is not a model for other countries, particularly not for larger countries.

> The sun is always shining somewhere.

This is simply not true.

> For Germany in particular it was a mistake to move away from nuclear

Absolutely. Probably the biggest political mistake of the after-war period.

[epistasis]

Also, batteries. Storage is being deployed in a huge fraction of new solar installs already, as time based pricing makes it extremely economical to add batteries even after only small amounts of solar penetration on the grid.

And there are great savings by packing batteries behind the inverters along with the DC panels. Inverters can be a shared cost between the panels and batteries. Already, falling panel prices make the inverters an be increasing cost. Second, because panels are so cheap relative to the full install cost, most installations already have undersized inverters compared to maximum solar output. This lets all that "wasted" energy get stored and delivered later when it has much more value and a higher grid price.

Honestly, in the year 2023, batteries are a much more capable and scalable and realistic grid asset than a nuclear reactor.

[epistasis]

> Having written these thoughts out I now realize your statement presumes we can ever (and always) meet 100% of electricity demand with wind/solar/hydro in the first place.

If you don't believe that we can meet our needs with wind/solar/hydro/batteries, then you haven't bothered to study the problem at all.

There's soooo much literature out there on how to do this.

And even without 100%, getting to 90% wind/solar is super cheap and deployable today, and by the time we spend the 15+ years deploying that, we will have tons of new tech to deal with the remains few percent.

Even France never got to 100% nuclear carbon free power, why not do the cheap thing to get to better than France levels of low carbon energy?

[plasmatix]

To be clear, I don't see it as either/or. No doubt a mixture of solutions is the optimal strategy.

If you have any literature to recommend, I'm happy to read it.

[goodpoint]

> But is it low enough?

Yes.