what happens to excess electricity produced on the grid

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Since, and unless electricity has properties I’m not aware of, it’s not possible for electric power plants to produce only and EXACTLY the amount of electricity being drawn at an given time, and not having enough electricity for everyone is a VERY bad thing, I’m assuming the power plants produce enough electricity to meet a predicted average need plus a little extra margin. So, if this understanding is correct, where does that little extra margin go? And what kind of margin are we talking about?

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38 Answers

Anonymous 0 Comments

One has mentioned Texas

Look up Texas

News headlines have talked about “how Texas was only 4 minutes and 37 seconds away from total grid collapse with devastating consequences.”

Similar to a choir singing in harmony, grid operators care about keeping frequencies just right (typically 60 Hz) and in harmony across the different pieces of the grid.

The key is balance. Grid operators work around the clock to keep the grid frequency in harmony. But it’s a constant cat-and-mouse game because demand and supply fluctuations are always influencing the frequency.

When frequencies get out of whack, that can cause all kinds of cascading problems that aren’t easy to fix, such as burning out engines and other critical components.

Part of why things can snowball into collapse so quickly is that a particular plant or piece of equipment can have protective cut-off relays that automatically isolate themselves from the grid to prevent those grid frequency problems causing local hardware damage.
But those cutoffs happen at the same time the grid needs more capacity plugged in, not less, so it accelerates the death spiral.
Since the Texas grid is isolated from the rest of the United States, it couldn’t easily import electricity from other states to maintain a stable grid frequency.

During the Uri storm, two things happened: supply went down as lines, pipes, and other equipment failed due to the extreme weather, while at the same time demand spiked as people tried to heat their homes.

That caused the grid-wide frequency to start dropping. So plant operators had to quickly shut down certain customers (to lower demand) and bring things back in harmony.
If they had been just 5 minutes slower (which was around 2 AM, no less), all of the spinning plates would’ve come crashing down.

And that’s where the weeks-months of aftermath would come in: once the whole grid goes down, it’s difficult and slow to boot it back up again due to the ‘black start’ problem. It’s just not as simple as ‘turning things back on.’

Put simply: going from 0% to 1% is harder than going from 50% to 100%.

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