Solar power has begun to transform the world’s energy system

The article doesn't mention a technology that deserves some attention because it counters the biggest and most obvious deficiency in solar: the sun doesn't always shine.

That technology is cables. Cables allow us to move energy over long distances. And with HVCD cables that can mean across continents, oceans, time zones, and climate regions. The nice things about cables is that they are currently being underutilized. They are designed to have enough capacity so that the grid continues to function at peak demand. Off peak, there is a lot of under utilized cable capacity. An obvious use for that would be transporting power to wherever batteries need to be re-charged from wherever there is excess solar/wind power. And cables can work both ways. So import when there's a shortage, export when there's a surplus.

And that includes the rapidly growing stock of batteries that are just sitting there with an average charge state close to more or less fully charged most of the time. We're talking terawatt hours of power. All you need to get at that is cables.

Long distance cables will start moving non trivial amounts of renewable power around as we start executing on plans to e.g. connect Moroccan solar with the UK, Australian solar with Singapore, east coast US to Europe, etc. There are lots of cable projects stuck in planning pipelines around the world. Cables can compensate for some of the localized variations in energy productions caused by seasonal effects, weather, or day/night cycles.

For the rest, we have nuclear, geothermal, hydro, and a rapidly growing stock of obsolete gas plants that we might still turn on on a rainy day. I think anyone still investing in gas plants will need a reality check: mothballed gas plant aren't going to be very profitable. But we'll keep some around for decades to come anyway.

Transmission lines are a interesting idea, but expensive.

Once solar is cheap (like now, as it already is), you can put in 3x what is needed on a sunny day, and power everything on cloudy days. Solar runs on cloudy days. Night obviously requires a different solution. Start by installing solar over all parking lots.

To think that you won't be able to run a 100% solar/wind grid is a bet against human ingenuity. If generation in excess of peak demand was installed of solar/wind, there are many promising approaches to deal with generation shortfalls. Batteries, load shifting, an electric vehicle fleet that charges during the day and powers the grid at night if the owner opts in, precooling a home with AC during the day to a low set point so AC isn't needed at night, H2 storage in salt caverns, pumped hydro, aluminum smelters that operate during excess power periods, the possibilities are infinite.

It won't be hard. Don't bet against human ingenuity.