[c0llision]

I think the idea that renewables have to be paired with large amounts of energy storage is not correct. In Ireland dispatchable power is used when wind is low. Natural gas, hydroelectric, HVDC, pumped storage. Lithium ion batteries are generally only used briefly while the gas power plant gets up to temperature because of their high cost. There are also HVDC interconnectors that allow excess wind to be exported to the UK and electricity to be imported from there when it is cheaper. They expect to be able to achieve 70-80% renewables using this system by 2030, and are currently at around 45%. From 2030 onwards the focus will be on decarbonising the remaining ~20% of electricity generation that is gas. How that will be done will depend mostly on how the technology matures in the meantime, but it will likely be replacing natural gas with hydrogen and biogas. Another option could be carbon capture. Or batteries if there is some technological breakthrough and the price of stored energy drops way below it's current 200euro/MWh price.

I also think that electricity grids are very complex and powering any large grid with 100% of any one source is impossible. As each energy source has different pros and cons, you'll generally always have a mix of different sources.

[andsoitis]

> I think the idea that renewables have to be paired with large amounts of energy storage is not correct. In Ireland dispatchable power is used when wind is low. Natural gas, hydroelectric, HVDC, pumped storage.

Natural gas is neither renewable nor emission-free when burning, albeit less than burning coal, for instance. About 117 pounds of CO2 are produced per million British thermal units (MMBtu) equivalent of natural gas compared with more than 200 pounds of CO2 per MMBtu of coal and more than 160 pounds per MMBtu of distillate fuel oil. Source: https://www.eia.gov/energyexplained/natural-gas/natural-gas-...

So while using natural gas is better than using coal, in the longer term we likely needs to reduce its usage and substitute with renewables too.

[pydry]

We cant switch overnight.

It takes about 1/10 or 1/20th the amount of time and 1/5th the cost to build equivalent solar production. It's better to start with that and let pumped storage, batteries and hydrogen play catch up than pay 5x more and wait 10-20x longer for equivalent levels of nuclear power production.

Right now we use so much natural gas that a GWh of solar or nuclear produced energy is essentially just a GWh of natural gas that never gets burned.

That GWh can be produced in two years less consistently or twenty years more consistently. Which do you choose?

Id take two years. Storage and demand shaping infrastructure will catch up.

[8bitsrule]

>Storage and demand shaping infrastructure will catch up

Storage in particular could be MUCH cheaper. (And still be centralized to conserve public-utility oversight and dangers from all those saboteurs out there somewhere.)

Battery storage is VERY expensive and hard on the environment. I continue to see little attention being paid to merely simple gravity storage.

Yes, traditional large-scale pumped hydro exists (usually using expensive turbines to pump water uphill, like the plants used in the UK for decades to get past tea-time. There are many more in the U.S.) They're usually expensive (good for getting tax-payer dollars into constructor pockets) ... time-consuming as well ... and need a hill for a reservoir and a water-source. (Of course we have -all the time in the world- right?)

But on a large scale, electricity can also be stored much more simply and economically by moving VERY heavy weights uphill ... or lifting VERY heavy weights out of a hole. Already existing and proven steel cables can lift 'barrels' containing hundreds or thousands of tons of (very cheap) rocks. Construction times and $/MW cost savings over high-tech 'solutions'? might be 10-1000 times lower.

[belorn]

Let say a natural gas power plant has a life time expectancy of 20 years. If we say that in 20 years we can abandon natural gas with nuclear, then lets put that as a deadline for when the last natural gas power plant will be demolished.

We need to stop building new natural gas power plants and existing ones need to have a planned obsolescence so that investors know when their investment will no longer be worth anything.

[c0llision]

gas power plant != natural gas power plant. Green hydrogen gas generated from excess renewables and biogas exist, and can often be used in existing power plants. Though they are expensive right now, we've no idea how the technology may evolve in the next few years.

In Ireland they are actually building natural gas power plants with the assumption they will be stop operation as little as 5 years and only used for emergency purposes from then on. This is because they are using OCGT gas turbines which were invented for use in 3rd world countries and are much cheaper than conventional CCGT gas turbines.

Also don't forget that nuclear power plants have to go offline for maintenance like everything else, and I'm not sure it will ever be financially viable to have redundant nuclear power plants. France recently had to take 50% of their power plants offline for a few months to fix cracks and Japan had to take all of them offline for a few years after Fukushima. Thats why it's necessary to have emergency backup power plants and right now these are typically gas.

[godelski]

Fun fact. Nuclear power can technically load follow. It just generally isn't a good idea because it isn't very cost effective to not be running your nuclear power plant at all times. Also fun fact, nuclear power is really useful for high energy intensive operations such as splitting oxygen and hydrogen atoms from one another.

Side note: The France story is much more complicated. It doesn't sell narratives well, but what can I say, truth is complicated. It's not going to fit into this comment, but it has to do with regulations, covid, Ukraine, Germany, lack of European self-sufficiency, economics, and so much more. It's best to not bring up France's recent nuclear fiasco unless you're willing to get into the weeds, because otherwise you'll just start a fight by anyone who knows a bit more but still not the full story (which means multiple people will argue confidently and a clusterfuck ensues). With no doubt, France has blame to play. But to give just a push to find more info, remember that inspections and maintenance are scheduled quite far in advance. That many had been pushed off because of a global pandemic, and then war broke out. One could say this was quite a series of unfortunate events. Yes, blame France, but placing all blame on France is like destroying all farms except for one and then blaming that farm for famine when it got overrun by pests (even if it was entirely that farmer's fault, was it?)

[cycomanic]

I think the point is that people often point to France as "look it works" (while simultaneously saying "there Germany terrible") when the reality is that no France doesn't just work (and yes failure modes are always about multiple disadvantages coincidences, all the other stuff is usually covered).

[AnthonyMouse]

> That GWh can be produced in two years less consistently or twenty years more consistently. Which do you choose?

Both.

Intermittent generation methods are more problematic the more of the grid you try to replace with them. You have solar generation during the day, you run your natural gas plants less during the day but still run them at night, great. Keep building solar until you can stop running them during the day at all. Installing that much capacity could take 20 years.

At that point you'd have to contend with what to do at night. But hey, by then the nuclear plants you started building today are online. You might also look into ways of speeding up the process, because it shouldn't take 20 years to do that.

[c0llision]

>Natural gas is neither renewable nor emission-free when burning

Yes you are correct, in fact I actually addressed that in the later part of my comment

>From 2030 onwards the focus will be on decarbonising the remaining ~20% of electricity generation that is gas. How that will be done will depend mostly on how the technology matures in the meantime, but it will likely be replacing natural gas with hydrogen and biogas. Another option could be carbon capture. Or batteries if there is some technological breakthrough and the price of stored energy drops way below it's current 200euro/MWh price.

When picking fruit from a tree, It's usually best to start at the lower branches.

[dragonwriter]

> When picking fruit from a tree, It's usually best to start at the lower branches.

No, when picking fruit its best to pick it in the order it ripens, and as it does so, irrespective of position on the tree.

It is generally easier and requires less special equipment to pick fruit from the lower branches, hence the metaphorical description of simple tasks as low-hanging fruit. The metaphor (while it may also indicate optimal ordering for some other tasks) is not about optimal ordering for picking fruit from a tree.

[chris222]

Overbuilding wind and using HVDC transmission to move it around is sometimes cheaper than battery storage since it compliments solar peak times well.

A similar project is being constructed in the Southwest United States:

https://news.ycombinator.com/item?id=38801943

3,500 MW of wind+ HVDC transmission for 11 billion dollars.

[PaulHoule]

Solar and Wind vary on both a diurnal and seasonal basis. It is one thing for the grid to have enough storage.

I was looking at this paper

https://www.eia.gov/analysis/studies/powerplants/capitalcost...

where solar is quoted at $1300/kwh and adding a battery that can store a little more than an hour of output brings that to around $1800/kwh. I see people quoting that one like it is gospel but that doesn’t seem to be enough storage. If you assume the system needs 12 hours of storage to get through the night you need 10 of those batteries and the cost is getting into the $3500/kwh range.

They quote the AP-1000 and NuScale around $6000. Solar looks cheaper now and maybe it is in the tropics but in the Northeast you are going to get a lot less power in the winter than summer so to keep the lights on all year you might need two of those solar installations (though I think the battery stays the same) and now you are getting around $5000/kwh so that gap with nuclear is getting smaller.

That estimate may be a bit pessimistic, but renewable advocates right now sound like the people who were saying nuclear would be “too cheap to meter.”

Now if you have excess capacity in the summer you could in principle use it for something but that is not trivial. If you use something half he year you basically double the capital cost. Do you hire workers to do nothing in the winter or do you lay them off? “Free” excess solar energy might be “free as in puppy” not “free as in beer.”

[padjo]

Ireland is bottom of the league in Europe for renewable use, so I don’t know why you think using them as an example is good: https://www.thejournal.ie/ireland-bottom-of-eu-table-for-use...

[mrspuratic]

You're conflating electricity generation and total energy use. Yes, 13% is crap, we're highly (and ridiculously) reliant on imported fossil fuels.

With respect to electricity generation then, Ireland is in the middle with 39% renewable electricity generation for 2022[0]. 2022 was "less windy" than average by about 2%, and 2021 lower again by about 6%[1]. The grid currently can sustain 75% renewables, substantial upgrades are in progress (capacity and ROCOF related) to get that up to 95%. This year (2023) was substantially better, in the first 10 months the average contribution from wind alone was 33%[2], this month the wind generation record was broken also[3] (~4.6GW). Hydro and other sources top renewables up by another ~6% [4].

[0] https://www.consilium.europa.eu/en/infographics/how-is-eu-el... [1] https://www.dnv.com/article/uk-and-ireland-windiness-2022-24... [2] https://windenergyireland.com/latest-news/7615-31-per-cent-o... [3] https://electroroute.com/new-record-for-irish-wind-generatio... [4] https://www.seai.ie/data-and-insights/seai-statistics/key-st...