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That's because you need literally days to get a nuclear plant running again. Coal plants can start within hours. But do you have numbers on how it's affecting

by foepys 7y ago

That's because you need literally days to get a nuclear plant running again. Coal plants can start within hours. But do you have numbers on how it's affecting coal plants? Maybe coal plants don't need so much cooling?

BOOSTERHIDROGEN 7y ago
Coal plant in hot weather affect the efficiency of cooling water thus the NPHR. Also if you cold start the coal plant, it takes a day sometimes
ohyes 7y ago
They don’t necessarily shut the nuclear plants down, they throttle the power output. It isn’t a strict on/off switch, but a controlled reaction. They said two were offline but it wasn’t said why they were offline. (Likely usual maintenance and refueling). You wouldn’t specifically shut down for this reason.
fulafel 7y ago
At least in France, a lot of nuclear is operated in load following mode, meaning they can operate at less than 100% power and do semi quick changes.
masklinn 7y ago
> That's because you need literally days to get a nuclear plant running again. Coal plants can start within hours. You don't shut down your nuclear plants, you moderate them up and down. Unlike e.g. Germany, France's nukes were designed (and are used) for very aggressive load following, reactors can output 30~100% of their rated power and can rate up and down at up to 5%/minute. Here's a twitter thread on the subject (in french) from early march: https://twitter.com/TristanKamin/status/1102620969808658432 https://twitter.com/TristanKamin/status/1102620969808658432 This is a bloke who apparently likes following france's electrical and nuclear networks, roughly speaking on March 4 checking the previous week's data they saw that only 40 out of 50 reactors had been running (= more than 50% of rated power) on sunday, looking at electical demand it had fallen 15GW from early feb to early march (march was quite warm), nukes had dropped 10GW between saturday and sunday: not only was demand low (usually the case on french sundays) wind power had gone crazy. Gas plants were completely shut down (except those used for both electricity and heating), hydro was at the lowest possible level, pumped hydro had pumped all it could. Checking neighbours, Germany and Austria had spent part of the weekend with sub-zero electricity prices (they were paying surrounding countries to take electricity off of their hands). From sunday to monday, demand picks up like mad, and the nuke network handled overall increases of 50~100MW/mn over the morning (it still had to be supplemented by hydro and gas as consumption rate of changes exceeded 150MW/mn). This is the graph of nuclear production changes over the week-end: https://twitter.com/TristanKamin/status/1102625880520699911/photo/1 https://twitter.com/TristanKamin/status/1102625880520699911/... the sunday lows went down below 38GW, the highs on either side are above 50.

by foepys 7y ago

BOOSTERHIDROGEN 7y ago

Coal plant in hot weather affect the efficiency of cooling water thus the NPHR. Also if you cold start the coal plant, it takes a day sometimes

ohyes 7y ago

They don’t necessarily shut the nuclear plants down, they throttle the power output. It isn’t a strict on/off switch, but a controlled reaction. They said two were offline but it wasn’t said why they were offline. (Likely usual maintenance and refueling). You wouldn’t specifically shut down for this reason.

fulafel 7y ago

At least in France, a lot of nuclear is operated in load following mode, meaning they can operate at less than 100% power and do semi quick changes.

masklinn 7y ago

> That's because you need literally days to get a nuclear plant running again. Coal plants can start within hours. You don't shut down your nuclear plants, you moderate them up and down. Unlike e.g. Germany, France's nukes were designed (and are used) for very aggressive load following, reactors can output 30~100% of their rated power and can rate up and down at up to 5%/minute. Here's a twitter thread on the subject (in french) from early march: https://twitter.com/TristanKamin/status/1102620969808658432 https://twitter.com/TristanKamin/status/1102620969808658432 This is a bloke who apparently likes following france's electrical and nuclear networks, roughly speaking on March 4 checking the previous week's data they saw that only 40 out of 50 reactors had been running (= more than 50% of rated power) on sunday, looking at electical demand it had fallen 15GW from early feb to early march (march was quite warm), nukes had dropped 10GW between saturday and sunday: not only was demand low (usually the case on french sundays) wind power had gone crazy. Gas plants were completely shut down (except those used for both electricity and heating), hydro was at the lowest possible level, pumped hydro had pumped all it could. Checking neighbours, Germany and Austria had spent part of the weekend with sub-zero electricity prices (they were paying surrounding countries to take electricity off of their hands). From sunday to monday, demand picks up like mad, and the nuke network handled overall increases of 50~100MW/mn over the morning (it still had to be supplemented by hydro and gas as consumption rate of changes exceeded 150MW/mn). This is the graph of nuclear production changes over the week-end: https://twitter.com/TristanKamin/status/1102625880520699911/photo/1 https://twitter.com/TristanKamin/status/1102625880520699911/... the sunday lows went down below 38GW, the highs on either side are above 50.