[Power] Aug 21 solar eclipse will reduce US energy generation by 9MW

Aug 13, 2017 28 Replies

Interesting. Article on how the upcoming solar eclipse will temporarily reduce US energy generation by ~9MW due to loss of solar, requiring gas and hydro reserves to be brought online.



"During the upcoming Aug. 21 eclipse, operators of giant solar fields from California to the Carolinas will rely on power from fast-start natural gas generators as well as hydroelectric plants and other sources to fill the gaps as the sky darkens. The celestial event, the first total solar eclipse visible in the lower 48 states since 1979, will provide owners of gas turbines a chance to shine even as the fossil-fuel is expected to be displaced over time by solar and wind energy"



But in terms of the US total generating capacity, it's trivial (and I know you meant 9GW, but it's still trivial, less than 1% in fact). They lose more than that every night. In 2015 the total solar capacity was only 1.3% of total generating capacity, 13.7GW out of a total generating capacity of 1,064GW.

From

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I am sure they can cope as the same thing happens every night.

Well yes but hang on a moment what about night times?

Its only going to be less than an hour or so and its all over.

I'm wondering why this is a problem, if it is one that is.

Never mind Sodium air batteries are 'just round the corner' as they have been for ten years or more...:-) Brian

En el artículo , therustyone escribió:

Yes. Just testing.

:)

En el artículo , Chris Hogg escribió:

Agreed. I found it interesting from the viewpoint of having the necessary alternative capacity available and ready to bring online at a moment's notice to cope with the sudden loss of solar.

I read an interesting article a couple weeks ago about the Germans having trouble operating their (remaining) nukes in load-following mode. Apparently it makes them unreliable and shortens their lifetime. Something I hadn't expected, given the reaction can me controlled/varied by using the control rods.

En el artículo , The Natural Philosopher escribió:

No s*it, Sherlock. That 40-year-old theoretical degree stands you in good stead, doesn't it?

I used to work with someone who had previously worked on a reactor simulations. He said that nuclear reactors are like wobbly jelly. If you put control rods in "here", there are responses over "there" and it all takes (a long) time to make fine adjustments.

And with at least some designs it's a "bad thing" to keep mechanically stressing the control rods; and even if those are designed for the job - or other means used to control output - there's the problem of thermally stressing the whole thing. That shortens the lifetime which, coming on top of running at less than full capacity, means load following is a double-bugger-up to the economics of reactors (ie high capital cost, low marginal cost of output).

En el artículo , Huge escribió:

That's... confidence-inspiring.

Yes, I saw that. Probably either Mearns' blog or WUWT; can't remember now. But it may explain why UK nukes' output is as steady as a rock.

It's the rate of ramping up and down the non-solar sources that's the issue, seems like they're going to disconnect the big solar farms in advance, so it just leaves the Californian versions of Harry to worry about, who will all of a sudden be asking the grid to make up their loss.

It is your understanding of *where* the corner is in relation to where we are now that is the problem :-|

Ramp down and ramp up are not usually so quick, though. Time to wind the gas up and then down is quite short ISTR.

However a fast moving thunder cloud could have a similar effect, no doubt.

Cheers

Dave R

And, apparently, there's similar planning going on for the near total eclipse in the UK in 2026.

Note that I said "fine adjustments". Scramming the reactor is very quick, although it may take days to cool down.

En el artículo , Chris Hogg escribió:

I'll have a furtle and see if I can find it again. Possibly PEI.

and wrong for later reactors.

No, it doesn't.

Nukes are run flat out because the fuel costs nowt and thats the most profitable mode.

A few are throttled back a bit because of weak boilers.

France throtlles its fleet extensivley because they have more than enough.

Works OK with new fuel rods but later in xenon poisoning starts to make it more difficult.

Ramp rate isn't that huge. Hydro can easily deal with that if they are ready.

Or if not do the obvious and disconnect some solar early.

Its a non=story.

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