Spread out generation doesn't take the issue of night power usage out of the picture
Sure. But greening the grid has
stages...
In
Stage 1, intermittent renewables displace fossil fuels, up to about 20% of energy produced, and do that without major changes to the grid, mostly by throttling gas generation (which has excess capacity in much of the US). Batteries are not required in this stage, and if you do build them they act like peakers and have minimal climate impact bc they actually store fossil generation for use later.
Fossils back up RE in this stage during nighttime and cloudy days. Also lots of things like coal get retired and replaced by gas here, so long as gas prices stay low (aided by demand reduction from solar).
In
Stage 2, RE exceeds 20% of energy produced on the grid, and this means that RE generation exceeds demand during some days (like sunny weekends). This production must either be curtailed (which is low cost, but dents profits) or stored in a battery (ignoring things like pumped storage). Which of these two things you choose depends on the cost of power you are getting and the cost of batteries. Given the cosine curve of conventional solar, you can also install your solar east/west to flatten the production curve, but again at lower over production per installed Watt (as you know). Batteries that you DO install to overcome curtailment only need to store a fraction of the produced energy and sell it back during early evening high demand period (say 4 hours).
Ultimately, maxing out batteries in this scheme would allow production following demand from midmorning to early evening on sunny days, which would typically be more than 50% of total daily demand.
Fossils (mostly gas) still back up RE in this stage on cloudy days and during nightime after the 4 hour batteries are spent. Maybe 30%-50% of total demand depending on local solar resource. So RE covers 50-70% of energy.
In
Stage 3, you need to build build BIGGER batteries and arrays to cover evening demand, and also partly cloudy days. Now you can get to 75-90% of energy depending on local solar resource and wind mix.
Chasing that last 10-25% of fossils off the grid (Stage 4) is hard. It will likely not happen in some regions for some time. Regions with hydro and legacy nukes can get to 100% carbon free electricity in Stage 2 or 3.
So, most places in the US are still in Stage 1. California and Hawaii and arguably Texas are in Stage 2. So that is where the batteries are at.
For decades, people argued that solar could never get over 1% of energy, too expensive. Then they argued that the grid would collapse if RE went over 5-10% of energy, too intermittent. Then they argued that over 10-15% curtailment would be necessary and further expansion would be impossible economically. Those arguments were based on the ideas that
grid batteries would never work.
And yet here we are, in a world with grid batteries being deployed, but only where they make sense and then seemingly rather small (bc Stage 2). And that is what it looks like when RE energy production is >20% and <50%. And ofc those grid batteries have a learning curve, so they will get better and cheaper as more are built. So the fact that they are being fielded (rather than sitting on a bench in a lab) is
really important. Watch this space.
Regarding the original post column, the author is arguing that the NYS goals (to reach into Stage 2 by 2030) are impossible, but assumes that grid batteries don't exist. This seems to me to be common thinking from about a decade ago, that Solar was nice and all, but would never exceed 20% of energy. Since the NYS goal is to exceed that, of course he thinks it impossible.
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