As long as the gas plants aren't burning any natural gas, I would say that's fair.
Standing by to supplement power on load spikes is one of the primary roles of gas plants (together with pumped hydro), and that they didn't need to supply any electricity over those six days is noteworthy.
From a climate standpoint there also isn't much wrong with having generating capacity in fossil fuels, what matters is how many greenhouse gases and how much pollution they put out. Which isn't much if they are just standing by.
No? Either you have enough nuclear to cover 100% of peak demand, in which case you just run them exclusively (at a terrible capacity factor) because nuclear is almost exclusively capex, or you don't, in which case you need gas peakers.
Nuclear is emphatically not an instant-on hot backup. Plants take time to spool up, and very importantly time to cool down. Fukushima happened because you can't just turn a reactor off, it produces energy that has to go somewhere while the intermediate fission products decay over hours-to-days.
> Fukushima happened because you can't just turn a reactor off,
Fukushima happened because the plant was hit with both an earthquake and a flood significantly exceeding its operational parameters (already extremely high)
> Fukushima happened because the plant was hit with both an earthquake and a flood significantly exceeding its operational parameters (already extremely high)
That's exactly the incorrect analysis that caused the meltdown!
That use of "and" and "both" is simply wrong. It wasn't an unforseeable collision of two events, it was a single event (an earthquake) with a predictable correlate (a tsunami). It's not like people didn't know that tsunamis follow earthquakes, and no one who does know that would make the argument you just did.
This was literally the definition of a black swan event: "an event that comes as a surprise, has a major effect, and is often inappropriately rationalized after the fact with the benefit of hindsight"
In this scenario you could just run the nuclear plant all the time, but just direct its electric production to heating a giant pool of water or whatever.
Then when the grid needs more power you do less of that, and instead send electricity to the grid.
Yes, but the point is that the problem is isomorphic to wind or solar: you get power when you don't want it. So nuclear isn't backstopping any particular need, it has the same drawbacks. The reason gas plants are used as peaker plants is that they can be turned on and off more or less instantly.
You're just assigning magical value to "turn it off".
That's only a big deal with fossil fuels due to the fuel cost, the fuel cost of nuclear is marginal.
Yes, I agree that it's stupid to build a (big) nuclear power plant only to use it to boil an Olympic sized swimming pool most of the time.
But that's stupid because we're over-relying on "green" energy that can't provide baseload power.
It's even more stupid with fossil fuels, now you also need an entirely different backup infrastructure, but the fossil one pollutes much more than nuclear.
How would they regulate fluctuations in demand? Nuclear can’t do that. You need storage, or a reasonably scalable generation medium. Nuclear as a base load is moot
You can technically use nuclear power plants as load followers in much thr same way that you can technically keep warm by setting $50 bills on fire.
Load following with a nuclear plant basically means provisioning a 2GW plant and then using, say, 0.5GW of that - throwing away the rest.
(since the vast majority of the cost is capex not fuel)
Every kilowatt hour produced by that 2GW power plant is already 5x the cost of a kilowatt hour produced by a wind farm. If you assume it is used for load following that goes from 5x-20x depending on capacity utilization.
Pumping water uphill (snowy 2, coire glas, etc) is way way WAY cheaper and the geography to do that is ridiculously common.
Electrolyzing water and storing hydrogen underground is way cheaper too, and can be stored for months cheaply.
Nuke plant -> btc mining with excess load when load is not demanded
Nuke plant -> consumers when in demand
Pretty easy equation, much more reliable and much more scalable and not subject to the whims of the elements / can be done anywhere and on any planet in the solar system.
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.
Quote:
« un réacteur peut varier de 100 % à 20 % de puissance en une demi-heure, et remonter aussi vite après un palier d’au moins deux heures, et ce deux fois par jour »
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.
Even in nuclear-packed France (which exports electricity) fossil fuels are also burnt in order to produce electricity since nuclear's inception, for most of the load-following and peak (about 9% in 2021), and it would be much worse without hydro.
https://ourworldindata.org/grapher/share-elec-by-source?coun...
On the other hand green hydrogen (produced by intermittent renewables at over-electric-generation time) can be stored then used at insufficient-generation time.
Yes - the plants are on standby, not consuming much beyond a "pilot light" worth of natural gas and not putting energy into the national grid.
This is quite different to coal fired power generation which doesn't have low energy standby mode with rapid online to full generation ramping up in the manner of gas fired turbines.
During the six day period the national grid was supplied only with energy from renewable sources.
At the cost of building enough solar and wind farms to supply the nation I would guess, with additional costs to upgrade the distribution infrastructure for smarter load balancing, etc.
It's quite possible Portugal has put out a white paper on their transition toward renewable energy that you can find with some hunting about.
Wikipedia has a rough overview that'll provide some points to drill down further into if you're interested in the per capita comparative costings of a hybrid national power scheme.
At a glance it looks like a paper worth reading so yes, that's the kind of paper I'd chase down (and still look for others).
Most countries have policy and costing papers, most companies file technical reports with stock exchanges, fossil fuel companies such as BHP have fat technical reports on the energy demands that they meet and project - these are all sources for hard data that can be compared (after normalising for apples V oranges).
The US is a mixed bag - Federal infomation is free and transparent, digging into details can get harder. The UK has a good civil service that puts out a lot of infomation on things that affect policy - from crime to consumption to energy use.
My comment was intended to encourage the user asking "at what cost" to form a better question and pursue their own answers.
What's the cost of maintaining both green energy plants & non-green plants for Portugal? What's the cost of electricity there? Is it subsidized (perhaps heavily)?
On one hand, solar and wind are very cheap - significantly cheaper than fossil fuels. On the other hand, you still also need either a significant amount of fossil fuel capacity or energy storage available to kick in during hours when solar and wind can't provide as much production. So instead of building enough fossil fuel production for 110% of your peak need, you might lower that to 50% and then still also build 110% of your need in renewable energy -- so you'd be over-capitalized at a total installed capacity of fossil fuels + renewables at about 160% of peak need.
So, marginal cost is lower. Total capital outlay might be higher. Portugal provides energy at an average of 9.7¢ / kWh which presumably is high enough to pay back all the capital costs in addition to the marginal costs. Mississippi only has 1% renewables and provides electricity at 11.55¢ / kWh.
So it would appear at a very rough glance that the answer to "At what cost?" is..."Negative cost".
For those six days they could. But even if we need fossil fuel as backup for some time, burning a lot less of it means we don't cook the planet as much.
And for good reason, it proves wrong the mainstream thinking that this is impossible. Quite a few countries already run the full year over 90% renewable[1] and we still neglect it with all kind of excuses.
If only they all listened to you! I don't have all the answers but a few of the ones I researched that are being built are needed to ensure people have heating through the winter in the next 3-7 years until reliable other solutions appear.
a lot of data there is pre-covid, would be interesting to see what’s happening today - especially in Europe, with the consequences of the Russia-Ukraine war on energy markets.
"The first half of 2023 saw a collapse in EU fossil generation, leading to the lowest output on record. Wind and solar continued their growth, with solar generation increasing by 13% and wind by 5%. Hydro and nuclear are recovering from their historic lows in 2022, though their long term outlook is uncertain."
The section "Wind and solar are leading the renewables charge" has graphs for each EU country showing H1 TWh generation by either fossil or renewables.
The issue is that renewables require extensive, expensive redundancies which are misleadingly excluded from the ubiquitous “renewables are cheaper” studies.
First give me a world that runs on 90% renewables all the time. The last 10% is really not something that will have weight.
Actually I consider complaining about that bad faith. Too many countries run on pretty much majority fossils, reducing that has the largest impact and setting an example will help there. A world where we run on 90% renewables is a good one.
First of all, to avoid the 2 degrees warming threshold, we need to be at net 0 emissions in like 10 years. Which absolutely requires 0% fossil fuels in electricity and heating, all year round, all over the world. 10% fossil fuels in electricity is nowhere close to good enough.
Secondly, the current best for renewables is nowhere close to 90% year round. Those 6 days in the article are a huge record for Portugal. 90% would essentially mean 330 days of exclusive renewables use, which no one in the world is close to, except maybe Iceland.
no, they do not. The vast majority of studies that estimate the LCOE for renewable generators consider only the spot price of electricity and OPEX costs. The cost of reliability is absolutely not factored into this energy cost.
The point of the article was that there is sufficient renewable capacity that the standby wasn't needed, for six days. So that's a milestone of some sort. Or, if not a milestone, then at least a checkpoint that shows that seven, eight, ten, or twenty days is only a matter of continuing to scale up.
Standing by to supplement power on load spikes is one of the primary roles of gas plants (together with pumped hydro), and that they didn't need to supply any electricity over those six days is noteworthy.
From a climate standpoint there also isn't much wrong with having generating capacity in fossil fuels, what matters is how many greenhouse gases and how much pollution they put out. Which isn't much if they are just standing by.