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A near 100% renewables grid is well within reach, and with little storage

reneweconomy.com.au

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Re: A near 100% renewables grid is well within reach, and with little storage

#41

Post by mikeyouse »

philipkglass wrote: post #35
theluketaylor wrote: post #31

Earlier quoted context omitted.

Losses wouldn’t be bad with HVDC, with the added benefit of HVDC ties not needing to be frequency synced across the entire grid, so you have some opportunity to increase resiliency. I don’t think it’s a one-sized fits all solution. There will be places where storage will make sense, and other where longer distance transmission makes sense. I think the reality is it will be a mix of both, along with a nice diverse mix…

Australia seems especially well suited for long-distance transmission because development is so heavily weighted to the coasts; there's not a lot of existing built-up interior areas to route around. At 800 kilovolts HVDC line losses are only 5% per 2000 km: https://publications.jrc.ec.europa.eu/repository/bitstream/J... (See page 11)

Yeah, people really underestimate how efficient HVDC has become. Even that doc is outdated - it was published in 2015 so likely based on 2013/2014 figures. Modern projects, e.g. ultra HVDC (1100KV) in China are seeing more like 1.5%/1,000KM losses: http://en.people.cn/n3/2018/0622/c90000-9474097.html

Re: A near 100% renewables grid is well within reach, and with little storage

#42

Post by ZeroGravitas »

biomcgary wrote: post #26

A relatively simple model that is still a reasonable ballpark. However, throughout the article I was wondering about the effect of transmission efficiencies across Australia. The author addresses transmission at the end by acknowledging that they didn't model it. Not sure how much it matters, but I suspect that lots of wires would be required.

Australia is currently reducing their transmission length (and risk of bushfires) by creating microgrids with solar and batteries for remote communities.

The battery rollout modelled, would also be able to reduce transmission bottlenecks by distributing them geographically, something the Australian grid has been encouraging for a few years now.

Re: A near 100% renewables grid is well within reach, and with little storage

#43

Post by jakewins »

Models show this same result for most (all?) regions they have been applied to. Here is a survey paper going over the current state of research globally and what mixes different models arrive at for different regions:

https://ieeexplore.ieee.org/document/9837910

Re: A near 100% renewables grid is well within reach, and with little storage

#44

Post by ebiester »

cm2187 wrote: post #10

The averages don’t tell me much. We need to look at percentiles with intermittent sources of energy. 99% still means 3 full days of blackout every year. So it needs to be sufficient to cover an even higher percentile (in fact I don’t even think there is an acceptable number of hours of blackout in a year). I would be curious how they get to that with energies that pretty much go to zero the week there is no wind.

Or, alternatively, a handful of gas plants working at this load like peaking power plants work now. So, for 72 hours or so, where the full need isn't met, we have some very expensive alternatives. According to wikipedia, some peaker plants may work as little as a few hours a year.

Or, we have a set of solar thermal energy power plants that can function as peakers down the road.

Re: A near 100% renewables grid is well within reach, and with little storage

#45

Post by mikeyouse »

plantain wrote: post #15
zdragnar wrote: post #6

Earlier quoted context omitted.

On its own, it does seem like a lot. Thinking about the nature of renewables where I live, it seems so small as to be not worth mentioning; January will often have a week to several weeks of heavy cloud cover and little wind. A mere 5 hours of capacity is a pittance. Australia, on the other hand, could easily make more sense, as I imagine the outback to be sunnier year round and maybe windier.

Cloud doesn't mean solar stops working - the decrease is 30-60% depending on thickness, but there's still very meaningful generation.

Especially depending on the season - clouds in the summer also typically correspond with a big drop in AC demand, reducing the amount of electricity required. That's why OPs modeling is so interesting, "real" daily data for an entire year is great for this type of planning.

Re: A near 100% renewables grid is well within reach, and with little storage

#46

Post by ZeroGravitas »

theptip wrote: post #36

Great analysis. I’m not so familiar with the AU energy market, so I don’t know how much of an update this result is vs. a reasonable prior. The bigger simulation mentioned in the OP is the ISP: https://aemo.com.au/energy-systems/major-publications/integr... . Anyone know what that plan proposes in terms of energy mix? > It is interesting to note that the ISP is predicting that approximately 9GW of peaking gas or liqu…

This is completely in line with reasonable priors:

https://www.wartsila.com/energy/towards-100-renewable-energy...

It's more of a science/engineering communication effort, because there's a lot of unreasonable priors out there.

edit: also the 6.6GW of 'other' the current model uses, is the current actual gas plant size, not an amount that they predict as optimal or desirable. Similar with the Hydro, they used the current capacity, even though some are being built right now.

Re: A near 100% renewables grid is well within reach, and with little storage

#47

Post by theptip »

wyager wrote: post #29
conjecTech wrote: post #22

One thing I would love to see addressed in these kinds of analyses: the efficacy of strategic placement of solar. Electrical demand tends to peak slightly after sundown for much of the year. However, the sun obviously doesn't set at the same time everywhere. Darwin's sunset is currently an hour and a half later than Sydney/Brisbane. Could building more equatorial/western solar installations together with transmission…

Transmission losses would eat any benefit, unfortunately. Of course, the author didn't model this at all. This is the problem with 99% of "actually we could totally rip out our entire infrastructure right now" posts - it's usually justified with crappy modeling that falls apart under slightly more scrutinizing consideration. Solar-only with low storage overhead might become more viable if we get room-temperature supe…

> Transmission losses would eat any benefit, unfortunately.

Big “citation needed” on that assertion.

HVDC is a widely proposed option and it’s an oversimplification to dismiss it with a single sentence.

For example the old DeserTec made a feasibility analysis for HVDC interconnects across EU and into Africa; the problem with that one seemed to be more about geopolitical issues and upfront investment costs, rather than long-term feasibility of transmission losses.

A newer analysis at the top of Google does not say “this doesn’t work because of transmission losses”. https://www.eia.gov/analysis/studies/electricity/hvdctransmi....

Re: A near 100% renewables grid is well within reach, and with little storage

#48

Post by snek_case »

wyager wrote: post #29
conjecTech wrote: post #22

One thing I would love to see addressed in these kinds of analyses: the efficacy of strategic placement of solar. Electrical demand tends to peak slightly after sundown for much of the year. However, the sun obviously doesn't set at the same time everywhere. Darwin's sunset is currently an hour and a half later than Sydney/Brisbane. Could building more equatorial/western solar installations together with transmission…

Transmission losses would eat any benefit, unfortunately. Of course, the author didn't model this at all. This is the problem with 99% of "actually we could totally rip out our entire infrastructure right now" posts - it's usually justified with crappy modeling that falls apart under slightly more scrutinizing consideration. Solar-only with low storage overhead might become more viable if we get room-temperature supe…

I see a lot of cynicism around renewable energy and electric cars and I frankly don't get it. The typical cynical approach is to point out one potential problem, and dismiss the entire solution as if it was worthless, which is obviously false.

As others have pointed out, there are now HVDC lines that can go over thousands of kilometers (transcontinental scale!) with reasonable losses. There's no reason to believe that we've hit the peak of HVDC technology either. The need for this technology to exist will drive further innovation.

Even if the OP's estimate is off. Even if we "only" get to 90% renewables by 2045, that's still pretty damn great compared to what we have now, isn't it? Is your cynical opinion that we should just keep going with the status quo because we can't get 100% ?

Even if we need 15% more wind and 15% more storage to than the OP's estimate reach 99%, that's not impossible either. It will create a lot of jobs. Why not just roll up our sleeves and do the best that we can? Thankfully, the world is not only made up of cynics, and a lot of people already are.

We aren't done innovating on the renewable front either. There's LOTS of research into cheaper, safer, more scaleable grid-scale batteries. The current state of the art is cobalt-free and nickel-free lithium iron phosphate, but people sodium-ion batteries look like they're going to be viable soon.

I also feel pretty confident that we'll eventually manage relatively efficient ways to store energy over the long term. If we could turn electricity into methane or ethanol with even 25% efficiency, that would allow us to store energy from the summer to use in the winter, or to power transatlantic airplanes with renewables. That seems pretty exciting to me.

Re: A near 100% renewables grid is well within reach, and with little storage

#50

Post by jakewins »

passwordoops wrote: post #5

Interesting, but the title should mention it's localized to Australia so as to avoid arm waving from either side

This survey paper shows the same holds true pretty much everywhere, with lots of different labs using different models arriving at the same finding:

https://ieeexplore.ieee.org/document/9837910

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