The grid is one of the world's largest real-time reactive machines. Power is generated on the fly as you need it. You could draw a direct path from your home A/C switching on all the way back up the chain to some source needing to push power to meet your demand.

The supply of the grid is a big mix of diverse sources: renewables, natural gas, hydro, nuclear, coal—whatever. Each power source has different pros and cons, and you cannot really over-index on one to have a reliable grid. For example, nuclear is a fantastic and relatively clean source for base load (obviously, when handled responsibly), but not great to provide power that reacts to the shifts of demand through the day. Solar, obviously, doesn't work at night. The grid operator has to build a supply mix that fits the needs of their region. (And that's typically by facilitating energy market with different energy products where generators bid and participate.)

With 2X overproduction, we've got lots of spare energy, so by the time we're getting most of our energy this way, we'll also have lots of energy for DAC, which can soak up the excess power whenever it's available.

Of course, that assumes that generation can be consistent. Right now, that is the case. If we took the existing grid and just gave everybody batteries, we could make power consumption flat throughout the day, which would greatly reduce costs. That would be cool!

The idea is that in the future, solar dominates. There you inherently have peak and non-peak hours, because you generate more electricity at noon than at midnight. This is completely impractical if you go straight from generation to use, because the times don't match up. But throw in storage to flatten it all out, and it works.

We already do that for industrial power consumers how are most capable of changing the time they put load on the grid.

For a decade or more New York has paid commercial and industrial customers something like $50M to shut down capacity on demand in exchange for lower electric rates.

Doing that delays or avoids $500M investments in power plants. Time shifting and solar build on this idea.

If you live in the boonies where power interruption is routine, partial power preservation means your fridge, well pump and heat continue to work. You don't need to worry about frozen pipes in the winter when your on vacation or lost groceries after a thunderstorm in the summer.

Let's start from a popular topic, ridden with propaganda of various sides, the Green New Deal. In theory we know we can't have more than very little p.v. or wind power because being very quick in output change no other classic power plant can keep the network at the right frequency: the Sun the sun rises, p.v. quickly grow to the peak, loads on classic power plants goes down too fast to adapt, frequency skyrocket causing a chain of blackouts, the sun sets and the load on classic power plant skyrocket, frequency plummet and large chunk of the network get cut out to reduce the load. The solution was and is named "Smart Grid" with storage, where the storage (batteries + inverters) are actually quick enough to compensate. The Sun rise, all connected cars start charging and so loads on classic P.P. remain almost unchanged. They slow down charging slow enough that classic PP crank down their production at a sustainable peace. Similarly in the evening all connected cars start discharging quickly compensate the very quick p.v. production loss, and stop discharging slowly allowing nuclear/gas/... PP to crank up at a sustainable peace. Or, so to speak, the extremely high costs of storage is offset to private individuals instead of being on energy operators shoulders. Such model does not happen because p.v. start to get economically sound, but until gasoline/diesel reach 3€/l (~11USD/gal) and/or the national grid became unstable most would not buy BEVs.

Another example is IT history: Xerox PARC invented and implemented the modern Desktop and desktop computing, the classic Paul Otlet/Henry La Fontaine Mundaneum idea in practice, than for business purposes such concept was crashed and developed few parts at a time by modern GAFAM in a way to ensure end users have next to no power and are locked in in their service.

Another example is the classic rent vs buy model where at first rent pay well, faster and cheaper, then the big cucumber arrives up the a* with rental prices to the stars and almost no more options to nor resources left to buy instead of rent.

Long story short: Science and technology works well ONLY if Science is PUBLIC, witch means NO research is done for private interests but for whole society one, and technology is UNDER Science, witch means the private sector select and pick new Science innovations and implement them on scale. So the model must be:

- a State, on top, witch means Democracy, witch means ALL PEOPLE on top;

- the State MASSIVELY found general interesting research maintaining universities, schools, labs, factories etc for the general interests;

- such PUBLIC apparatus produce innovations for the society;

- private sector grab ideas and hire some talents who do want to implement them instead of keep researching, try to sell resulting implementations, some will profit, some will fail.

All critical sectors are public only, so weapons are public only, health is public only (pharma for first), energy is public because we all need it, food due to it's nature is a mix BUT with a State/public regulation to ensure a minimum intake for all, basic transportation infra are public from TLCs to (rail)roads and harbors/airports. The rest is private.

NOTHING impede private research but having this far less resources only real success for the society will survive, modern absurd anti-society stuff get criticized by the compartmentalized public research, religiously separated from the private, and fails quickly.

For those who say "that's communism" or EQUALLY "that's fascism" do remember a thing: no market have proved to be or remain really free in a very short timeframe. No dictatorship have proven to last, they innovate quickly, expand quickly, than fall. The key is the old Roman's "est modus in rebus" or "there is a measure in anything" meaning, nothing can work taken to the extreme, there is no one-size-fit-all.

So no. Switch most commute to electric - then at first grid goes down, then power plants struggle.

"Most grids have a lot of spare capacity between, say, 9PM and 7AM" - that's not the grids we're talking about. HV circuits might not feel it, but something laid down for a suburb was scrupulously designed to carry only just enough, because it's basically burying refined metal, be it copper or aluminium.

There is no spare even 4KW for every house and never has been because that would have cost more in about everything - meters, cables, multiple stages of step-down transformers, transmission lines, generation.

Electicity is not free, never has been, and distibution costs are surprisingly a very important consideration.

There is an alternative to this, the equivalent of a credit union but for power where a number of people band together to do their own little grid, but the complexities and dangers involved make this a very difficult thing, especially once you factor in insurance and approval.

Yes it's true that 1:1 replacing the current power generation capacity with solar and wind is going to be really difficult.

BUT if we combine that with small-scale production (local solar/wind) and storage (small batteries in buildings) controlled by a smart grid, with the addition of automatically moving consumption to cheaper hours it's perfectly doable.

You don't NEED to run your dish/clothes washer and dryer the second you come home from work. You can fill them and time them to start so that they run during the night and are ready in the morning, for example. You get cheap electricity and the grid likes it when it gets use on quieter hours too.

I think batteries-- distributed or as part of utility-scale deployments-- can help a bit but are not economical enough to use to solve this problem.

It's going to take more of everything-- more solar overprovisioning, a lot more wind power, a fair bit of battery, more load shedding and demand pricing, more DC interconnect allowing power to be shipped large distances... and other stuff, like gas-to-power-to-gas and/or more nuclear baseload... to really let us move to an overwhelmingly renewable grid and have stable power.

The issue, IMO, is that there's many different timescales/types of shortfall (very cloudy couple weeks in winter with no wind vs. daily duck curve)... and then there's the 1 in 100 and 1 in 1000 events, too (heat wave in summer + overcast rolls in at 2:00PM trapping heat in all night with less insolation and little wind). Chemical storage can't blunt the longer timescale shortfalls much.