Right, but then how do you displace the remaining fossil fuel use? It's only a matter of time until the "other places" are also saturated. How do you get from 40-50% decarbonized energy to zero?

The solution is non-intermittent energy generation. Hydro and geothermal are great for places that have the right geography and geology. But nuclear is the only other non-intermittent form of decarbonized energy we have*.

* Some would point to biomass, but I don't consider them decarbonized: the biomass could have been a carbon sink if it wasn't burned. An it's not a very scalable form of energy anyway.

But nuclear is a terrible complement to intermittent power sources. Nuclear wants to run 24/7 - not intermittently.

IMO, gas is going to be around for quite a while as a peaker for renewables - and the more renewables come online, the less necessary it is as a peaker, but it will still be needed.

Right, which is why I'm more in favor of building nuclear to satisfy load all day around. Peak demand is when intermittent sources are producing the least. We need some form of decarbonized non-intermittent power to accommodate that. Hydro is great where we can build it. For everywhere else, there's nuclear power. And since nuclear power is just as cheap to operate around the clock, the latter regions can just skip the solar and wind.

I agree with you: if we use renewables we'll be using gas for 40-50% of our electricity needs until some scalable system of storage is found (batteries lack the scale, hydro lacks the geographic independency). But that's not an option if we want to decarbonize. The goal isn't to just have CO2 output. The goal is to eliminate CO2 output.

>Right, but then how do you displace the remaining fossil fuel use?

The cost effective way would be with wind farms, pumped/battery storage and demand shifting.

(this would be a nice problem to have, by the way, but we are STILL churning through terawatt hours of gas while the sun is shining and the wind is blowing all over).

Nuclear power isnt dispatchable. It's not just 5x more expensive. It would overproduce during times when we don't need electricity and underproduce when we do.

Pumped storage is geographically dependent. Batteries are nowhere near cost effective. "Demand shifting" is also hugely expensive: you can't just cut industrial inputs without causing adverse effects throughout the economy.

Nuclear power is dispatchable enough to satisfy grid usage. The difference between peak and minimum demand is typically 20-30%. And it's a pretty gradual transition, happening over the span of multiple hours. You're right, you can't just crank nuclear from 0 to 100% in an hour like a gas turbine, but a 100% nuclear grid is totally doable by overcooling the turbines to reduce outputs during low demand. The French have successfully used nuclear for over 85% of their electricity, so this is demonstrably capable.

You do exactly what Australia is doing and build PHES and dispatchable loads like electrolysis for fertilizer and smelting as well as adopting EVs.

Also your SA example is cherry picking a time when a bunch of transmission infrastructure has been destroyed because it was built to sub par standards and hit by a storm. When this happened last time there was only large centralised fossil fuel generation and there were weeks of blackouts and other problems. Seems like a pretty good case for more rooftop solar.

Unfortunately nobody has figured out how to deploy enough storage to make intermittent sources viable. Hence why plans for a renewable grid assume that compressed air, heated sand, or giant flywheels will deliver storage at orders of magnitude better than the existing battery and pumped hydro systems. Australia is not a big success story: Fossil fuels still comprise over 60% of electricity sources for Australia - it's no better than the USA. They are not using renewables for chemical and metallurgy industries. And this is despite Australia having some of the best weather and geography for solar power.

Sweden is the country making the most progress into green hydrogen, but it's still experimental at this point. Sweden also gets 40% of it's electricity from nuclear and 40% from hydropower, too. It's hardly a poster child for the success of wind and solar over nuclear power. Intermittent sources need to be backed by a dispatchable source. For countries that don't have widespread hydroelectric potential like Sweden, intermittent sources are not viable except as a supplement to fossil fuels.

> Unfortunately nobody has figured out how to deploy enough storage to make intermittent sources viable.

They're viable even without storage as evidenced by installing new capacity at a rate of net generation of about 20% of the entire cumulative nuclear fleet per year. And getting enough storage is well understood, it is just not a priority in most places until around 70% penetration and progress towards decarbonizing transport is met.

> Australia is not a big success story: Fossil fuels still comprise over 60% of electricity sources for Australia - it's no better than the USA. They are not using renewables for chemical and metallurgy industries. And this is despite Australia having some of the best weather and geography for solar power.

Australia has languished under a government that was openly hostile to renewables for years. South Australia has been operating at over 90% gross renewables for a week and this is after only a few years of large scale effort with insignificant storage and limited ability for interstate transmission due to storm damage.

> Sweden is the country making the most progress into green hydrogen, but it's still experimental at this point.

https://gh2.org/countries/sweden

https://gh2.org/countries/australia

Looks like about the same level of investment for similar targets to me. Could it be that was another example of blatant lies?

> For countries that don't have widespread hydroelectric potential like Sweden, intermittent sources are not viable except as a supplement to fossil fuels.

Yes. 90% for a week right near the beginning of the transition is a 'suppliment'. Very sound conclusion from the evidence at hand.

This constant lying must be exhausting. Just sell your coal shares.

Where are you getting the idea that 90% of South Australia's electricity is coming from renewables? Fossil fuels still account for ~35% of the state's generation [1]. You mention "for a week", so it sounds like this was under ideal conditions in the middle of the Australian summer. I could also cherry-pick data from the middle of winter to show a particularly bad week. The only state that has more renewable generation is Tasmania, and they produce it mostly through hydropower. Again, the constraints of intermittent sources energy continue to surface themselves. Australia has not found a way to escape this.

> Looks like about the same level of investment for similar targets to me. Could it be that was another example of blatant lies?

As per your links, Australia merely has targets while Sweden has actually produced and delivered green steel. In fact, again as per the link, Sweden has made the world's first delivery of steel produced without fossil fuels. I'm struggling to see how saying that the country that has actually produced green steel is making more progress than one that has not is a lie.

1. https://www.energy.gov.au/data/australian-electricity-genera....

It should be said that until the entire European energy supply is carbon free, green steel is not only incredibly expensive, but also bad for the climate.

It would be much better in both ways to feed that energy into the electric grid to replace fossil fueled power.

Norway has a similar initiative to produce carbon free ammonium, but that, too, depends on dirt cheap electricity supply to be rational.

https://www.horisontenergi.no/blue-ammonia/

In both cases, Hydrogen is used, and I suppose if large amounts of hydrogen becomes available and very cheap (for instance due to excess wind power supply), it _could_ be good to already have this tech available.

But based on what I can see from electricity flows from Denmark and Germany to Norway, it is still very rare for the European grid to have excess power due to good wind conditions.

https://www.nordpoolgroup.com/en/Market-data1/Power-system-d...

Norway can still absorb a lot more wind power on such days by temporary pausing hydro production. (Max hydroelectric electricity production in Norway is around 20GW, or about 4KW per capita).

Sweden and Norway both have 100% decarbonized electricity. Makes sense that they're the ones that are starting to make progress on decarbonizing chemical and other industries besides electricity.

Sweden and Norway are both part of the European grid, so excess power can be exported to Germany, the UK, Denmark, Poland etc where it can replace coal/gas based power. (In fact Norway and Sweden are required to do so as part of the ACER agreement.)

For now, that makes a lot more sense economically AND it replaces more carbon emissions per kWh.

> Where are you getting the idea that 90% of South Australia's electricity is coming from renewables? Fossil fuels still account for ~35% of the state's generation [1].

You're still making the point for me here. After only 5 years or so of actually supporting renewables and meaningful growth, and around two years of solar being the cheapest option, they're meeting 65% of the total electricity.

> As per your links, Australia merely has targets while Sweden has actually produced and delivered green steel. In fact, again as per the link, Sweden has made the world's first delivery of steel produced without fossil fuels. I'm struggling to see how you conclude this is a lie when your own sources explain how Australia has no plants or production, while Sweden has actually produced green steel.

Ah, so you're back to claiming that things that aren't already finished are impossible and irrelevant. Really working hard to find somewhere you can put those goalposts.

Also Lulea is in Sweden's north so your pathetic attempt at a gotchya was powered with hydro and wind, not Nuclear.