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> the more you decarbonize the economy, the worse it's going to get for renewables here since fossil fuels are used for highly non linear usage. A continental

> the more you decarbonize the economy, the worse it's going to get for renewables here since fossil fuels are used for highly non linear usage. A continental spread-out mix (wind, solar, hydro, geothermal, biomass...) reduces production variability ( this is tru even considering a single type of source: https://www.imperial.ac.uk/news/180592/european-cooperation-could-provide-more-stable/ https://www.imperial.ac.uk/news/180592/european-cooperation-... ) Overproduced electricity can be stored. V2G will play a major role. > You are mixing up two things I doubt so. I was stating that hydrogen may become a clean backup, replacing fossil-fuel existing plants, some of them (burning methane) may be retrofitted. Water electrolysis done in centralized plants gathering electricity overproduced at continental level in order to obtain and locally temporarily store hydrogen, maybe even benefiting from co-generation, will locally burn it (gas turbine or fuel cell) in order to produce electricity when the grid needs it while renewable sources cannot provide enough. > aren't needed for nuclear because you don't need P2G or any of that, you can just adjust the production Nuclear can 'modulate' its output up to a certain level and frequency, which in practice are insufficient. Even over-nuclearized France never enjoyed a zero-carbon grid: each year between 6% and 12% of electricity is produced by burning fossil fuel ( https://ourworldindata.org/explorers/energy?Metric=Share+of+total+generation&Total+or+Breakdown=Select+a+source&Energy+or+Electricity=Electricity+only&Select+a+source=Fossil+fuels&tab=chart&country=~FRA https://ourworldindata.org/explorers/energy?Metric=Share+of+... ) because exploiting enough reactors to cope with the mandatory load-following and also with the peak load would be way too expensive. There are safety-related limits (power modulation proportion, duration of a pause needed after each modulation, modulations frequency...) to nuclear load-following capacity, and the very combustible status is a major parameter. Pertinent document (French ahead!): https://www.sfen.org/rgn/expertise-nucleaire-francaise-suivi-charge-seduit-europe/ https://www.sfen.org/rgn/expertise-nucleaire-francaise-suivi... Proposed translation: "a reactor power output can vary from 100% to 20% in 30 minutes, then after 2 hours can go back to 100% at the same speed, and can cycle this way 2 times per day". This is quite a good performance when it comes to load-following (French engineers are very good at this), however it is insufficient in the real world (save any ridiculously expensive over-provision of nuclear reactor, most idling) and very weak compared to gas turbines performances. Those "bandaid" solution are needed with each and every low-carbon type of source, even nuclear. We have to consider the amount of emissions caused, in each type of system, by those solutions. On a grid when it comes to the "production = consumption" rule there are 2 big types of challenge: 1/ short-term adjustment (under a few seconds). Nuclear, per se, just cannot cope. It is done by the sheer inertia of the turbo-alternator drive shaft. On a renewable system it can also be done this way, thanks to flywheels. It is already done. 2/ long-term adjustments. It is either done by reducing the output of production units, or storing or wasting it or (if production isn't sufficient), by a reserve of "production" units (batteries, green hydrogen turbines...).

realusername 2y ago
> Those "bandaid" solution are needed with each and every low-carbon type of source, even nuclear. We have to consider the amount of emissions caused, in each type of system, by those solutions. Well no, they simply aren't. It's true that nuclear simply cannot do the same as gas but renewables on the other hand are in a league of their own way outside of any baseload tech. That's why they are considered intermittent. No nuclear fleet drops to 5% capacity for weeks at a time like solar or wind, that's simply not a thing. > short-term adjustment (under a few seconds). Nuclear, per se, just cannot cope. It is done by the sheer inertia of the turbo-alternator drive shaft. The nuclear fleet takes around 30min to adapt the production right now in France. Not only it is done but it works in real life right now, unlike large scale P2G, green hydrogen or batteries which aren't used anywhere on earth for grid management. > Overproduced electricity can be stored. V2G will play a major role. Unfortunately no it can't. Unless there's a new breakthrough, dams is all we have for large scale electricity storage. And we can't count on tech which doesn't exist yet. At the end of the day, the proof is in the pudding, even Germany which built tons of supposidly green hydrogen pipes will use them for transporting ... gas. > ( this is tru even considering a single type of source: https://www.imperial.ac.uk/news/180592/european-cooperation- https://www.imperial.ac.uk/news/180592/european-cooperation-... ) Well no, unfortunately that doesn't work either. And the best example is winter 2022 where the whole western europe was out of wind for 3 weeks. That's a nice idea but unfortunately it doesn't work with the real figures. You can even check right now on electricity map, most of the EU countries have similar wind capacity production at around 20%. (Terrible figure in itself but that's another debate) Edit : I forgot to answer that part. > Even over-nuclearized France never enjoyed a zero-carbon grid: each year between 6% and 12% of electricity is produced by burning fossil fuel ( https://ourworldindata.org/explorers/energy?Metric=Share+of+ https://ourworldindata.org/explorers/energy?Metric=Share+of+... ) because exploiting enough reactors to cope with the mandatory load-following and also with the peak load would be way too expensive. Unfortunately, France replaced a lot of the coal plants with gas plants to follow up renewables and is now stuck with it. France only had a single gas plant before 2010. The consensus at the time was that those renewables would eat up the share of the gas plant and they could be removed altogether. We now know that it doesn't work and the gas plants are there for good.
- 2y ago

realusername 2y ago

> Those "bandaid" solution are needed with each and every low-carbon type of source, even nuclear. We have to consider the amount of emissions caused, in each type of system, by those solutions. Well no, they simply aren't. It's true that nuclear simply cannot do the same as gas but renewables on the other hand are in a league of their own way outside of any baseload tech. That's why they are considered intermittent. No nuclear fleet drops to 5% capacity for weeks at a time like solar or wind, that's simply not a thing. > short-term adjustment (under a few seconds). Nuclear, per se, just cannot cope. It is done by the sheer inertia of the turbo-alternator drive shaft. The nuclear fleet takes around 30min to adapt the production right now in France. Not only it is done but it works in real life right now, unlike large scale P2G, green hydrogen or batteries which aren't used anywhere on earth for grid management. > Overproduced electricity can be stored. V2G will play a major role. Unfortunately no it can't. Unless there's a new breakthrough, dams is all we have for large scale electricity storage. And we can't count on tech which doesn't exist yet. At the end of the day, the proof is in the pudding, even Germany which built tons of supposidly green hydrogen pipes will use them for transporting ... gas. > ( this is tru even considering a single type of source: https://www.imperial.ac.uk/news/180592/european-cooperation- https://www.imperial.ac.uk/news/180592/european-cooperation-... ) Well no, unfortunately that doesn't work either. And the best example is winter 2022 where the whole western europe was out of wind for 3 weeks. That's a nice idea but unfortunately it doesn't work with the real figures. You can even check right now on electricity map, most of the EU countries have similar wind capacity production at around 20%. (Terrible figure in itself but that's another debate) Edit : I forgot to answer that part. > Even over-nuclearized France never enjoyed a zero-carbon grid: each year between 6% and 12% of electricity is produced by burning fossil fuel ( https://ourworldindata.org/explorers/energy?Metric=Share+of+ https://ourworldindata.org/explorers/energy?Metric=Share+of+... ) because exploiting enough reactors to cope with the mandatory load-following and also with the peak load would be way too expensive. Unfortunately, France replaced a lot of the coal plants with gas plants to follow up renewables and is now stuck with it. France only had a single gas plant before 2010. The consensus at the time was that those renewables would eat up the share of the gas plant and they could be removed altogether. We now know that it doesn't work and the gas plants are there for good.

2y ago