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My understanding (which is probably uninformed at best) has been that coal, nuclear, etc are used to cover base load, and basically work best when up and runnin

My understanding (which is probably uninformed at best) has been that coal, nuclear, etc are used to cover base load, and basically work best when up and running at 100% all the time. Natural gas has the advantage that it can be spun up and down pretty quickly, which has meant that it is used primarily for "peak" load, which I think used to be covered a lot of the time by things such as diesel and oil plants and have basically been supplanted at this point by natural gas. Solar and wind have the trouble that they are unreliable, which means you need something to smooth out demand. This is something coal and nuclear are poor at, meaning if you are bringing solar and wind into the mix on a large scale, natural gas becomes even more appealing since you can spin it up / down to balance capacity. A thing I don't see mentioned very often is the relative density of each power source. One of the things nuclear and coal have going for them, is that you can supply a lot of electricity in a fairly limited footprint. Wind and solar a much less dense, meaning you need to cover a much larger area, and you need it to be more distributed rather than all concentrated in one place. All of this is to say that I think everything is inter-related much more than people realize. Shifting to using more solar / wind creates a pressure to move away from coal / nuclear even without considering the "clean energy" aspect.

mpweiher 7y ago
"...to build new wind and solar farms equipped with storage systems" I think the "with storage systems" part is crucial here.
baking 7y ago
Excellent point. This should be the top comment. Buying up cheap solar and wind power during peak supply times and storing it for peak demand times should be more cost effective than building expensive gas/steam plants which would only operate for a few hours a day. It doesn't mean that we've found a solution for base load yet.
beat 7y ago
That's exactly what the market is doing, right now. The more wind/solar we get, the cheaper and more robust they are. And when they start costing a lot less than coal/nuclear (which is where we are now), then coal and nuclear basically collapse under their own cost - which is what is happening. The fact that gas saw a big cost cut around the same time is just accelerating the inevitable. But getting off carbon will require that wind/solar become significantly cheaper than gas as well as coal/nuclear. Which may be what happens over the next couple of decades.
godelski 7y ago
Pretty accurate, but nuclear can spin up and down, by controlling the fuel rods. This is one of the major advantage of the technology and why many suggest it be used in combination with solar, wind, and hydro (many as in the IPCC, which is why CNN pushed hard on everyone during the climate debates). It can be used to provide a base load (greatly reducing the need for batteries (or the need to invent good enough ones!) And can also scale back when it's sunny and windy. All while producing no emissions when running.
- baking 7y ago
  Chernobyl happened during a scheduled shut-down test that was delayed by 10 hours because there was higher than expected electricity demand. They tried to speed-up the shut-down and the results did not go as expected. I think it may be a little naive to say that nuclear can spin up and down by controlling the fuel rods. I think Three Mile Island and Fukushima also had issues with getting rid of residual heat during a shut-down that at a minimum damaged the fuel and resulted in a loss of the unit at TMI and a melt-down and major cleanup at Fukushima. It seems to be the basic safety issue with fission and not one that can be dismissed so easily. 6-10 hours for a controlled shut-down seems to be the minimum safety margin.
  - war1025 7y ago
    There was a video I saw a while ago, but I don't remember where, explaining that modern nuclear designs use passive safety mechanisms, whereas the original (currently in use) designs have active safety mechanisms that require ridiculous amounts of fallback and backup systems that make it much more difficult to guarantee safe operation in the event of an anomaly. I think it had something to do with there being a salt plug that would melt if things got to hot, at which point everything would drain into a vessel designed to stop the reaction getting out of hand. So the cooling systems have to actively keep operating temperatures in range otherwise the plug melts and it goes into safe mode. This is in contrast with what you describe where "shut down" is an elaborate process that takes time and correct order of operations in order to occur safely.
    - 7y ago

mpweiher 7y ago

"...to build new wind and solar farms equipped with storage systems" I think the "with storage systems" part is crucial here.

baking 7y ago

Excellent point. This should be the top comment. Buying up cheap solar and wind power during peak supply times and storing it for peak demand times should be more cost effective than building expensive gas/steam plants which would only operate for a few hours a day. It doesn't mean that we've found a solution for base load yet.

beat 7y ago

That's exactly what the market is doing, right now. The more wind/solar we get, the cheaper and more robust they are. And when they start costing a lot less than coal/nuclear (which is where we are now), then coal and nuclear basically collapse under their own cost - which is what is happening. The fact that gas saw a big cost cut around the same time is just accelerating the inevitable. But getting off carbon will require that wind/solar become significantly cheaper than gas as well as coal/nuclear. Which may be what happens over the next couple of decades.

godelski 7y ago

Pretty accurate, but nuclear can spin up and down, by controlling the fuel rods. This is one of the major advantage of the technology and why many suggest it be used in combination with solar, wind, and hydro (many as in the IPCC, which is why CNN pushed hard on everyone during the climate debates). It can be used to provide a base load (greatly reducing the need for batteries (or the need to invent good enough ones!) And can also scale back when it's sunny and windy. All while producing no emissions when running.

baking 7y ago
Chernobyl happened during a scheduled shut-down test that was delayed by 10 hours because there was higher than expected electricity demand. They tried to speed-up the shut-down and the results did not go as expected. I think it may be a little naive to say that nuclear can spin up and down by controlling the fuel rods. I think Three Mile Island and Fukushima also had issues with getting rid of residual heat during a shut-down that at a minimum damaged the fuel and resulted in a loss of the unit at TMI and a melt-down and major cleanup at Fukushima. It seems to be the basic safety issue with fission and not one that can be dismissed so easily. 6-10 hours for a controlled shut-down seems to be the minimum safety margin.
- war1025 7y ago
  There was a video I saw a while ago, but I don't remember where, explaining that modern nuclear designs use passive safety mechanisms, whereas the original (currently in use) designs have active safety mechanisms that require ridiculous amounts of fallback and backup systems that make it much more difficult to guarantee safe operation in the event of an anomaly. I think it had something to do with there being a salt plug that would melt if things got to hot, at which point everything would drain into a vessel designed to stop the reaction getting out of hand. So the cooling systems have to actively keep operating temperatures in range otherwise the plug melts and it goes into safe mode. This is in contrast with what you describe where "shut down" is an elaborate process that takes time and correct order of operations in order to occur safely.
  - 7y ago