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Comment by aqme28 | Hacker News Reader

Well if you generate enough excess power, you hardly need to store any.

Now you shifted the problem to power transmission, because there's no way to generate an excess of power at all times in all locations using just wind and solar.

So while in my region at the time of posting this, 100% of electricity is generated by wind, there'd be 100% less if there was no wind (which happens from time to time).

Solar wouldn't help either, because right now it's dark outside and it will stay dark for another 6 hours.

So right now, even if there's an abundance of power generated elsewhere, it would have to get transmitted efficiently to here (and from here to where it's needed if applicable).

Local storage and massive interconnected power transmission capacity is what's required. And that ain't cheap.

My point is that if you have enough of something, it stops mattering as much how efficient you are with it.

Unfortunately no. Whatever power you generate you have to send somewhere. Excess generation will push the grid frequency high and destabilize the grid in much the same way that insufficient generation will pull the frequency down and destabilize the grid. Storage doesn't just provide power during low generation, it provides somewhere for power to go when generation outpaces demand.

This doesn't sound right.

With solar a small solidstate relay can disconnect individual panels as required, or a larger relay can disconnect strings of panels.

I was replying specifically to the "It doesn't matter if we just make enough" idea. For solar panels on a site scale you can use variable pitch panels focused on a solar collector to control your output power if you are peaking to high. Wind can use variable pitch turbine blades. Both of these configurations add a lot of cost but are worth it when talking grid scale generation and aren't uncommon in practice. The actual power you put onto the grid does need to be matched to how much is being used. Storage (hydro is the most popular it doesn't have to be batteries) allows for cheaper generation because you have a lot more options for burning off overshoots and peaks with the benefit of smoothing out dips. Without storage all of this together gives rise to weird things in practice like California selling power at a loss to Arizona and then buying it back because of the combination of subsidies and grid stability.

If generation outpaces demand enough and there's nowhere to put it, can you not just send some to ground? Or reduce your generation?

Consistency is the reason to store, not amount. The sun doesn’t shine at night and the turbines don’t spin without wind (which also is more likely at night). Modern society is built on always available electricity, and some things absolutely require them (eg a data center).

This makes no sense.

Without storage excess power is useless at best, dangerous at worst.

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