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You don't seem to consider a few things:

- Why not build wind where there are natural strong winds and solar where there is naturally a lot of sun?

- Solar is more modular - you can have one panel on a residential house, and you can have thousands of panels in a farm. But you can't have wind turbines in residential areas.

- Costs.

- We don't need a single 100% reliable source (none is), we need a clever combination of sources to achieve 100% together with the lowest total cost per energy unit.

> Why not build wind where there are natural strong winds and solar where there is naturally a lot of sun?

The simple answer is: Because you don't need to do that.

You can build wind wherever it works best and will not be detrimental (from NIMBY to environmental factors) and deliver the power where needed.

How far can you go?

The UK are doing a project that will deliver power from approximately 4000 km away. In other words, if we limit ourselves to thinking about the US continental region, you could build a wind farm in California and deliver the power across the country to Maine.

Thankfully we don't have to go that far. We could build a bunch of wind farms in optimal areas and move power anywhere from there. My guess --and I have not done the research on this at all-- is that, at most, we would need to move power a few hundred miles from most sites.

> Solar is more modular - you can have one panel on a residential house, and you can have thousands of panels in a farm. But you can't have wind turbines in residential areas.

Absolutely correct. I happen to think that solar at homes and commercial buildings is a good path. This study, unless I am mistaken, is only about grid-scale technologies. My thinking at the moment is that, at grid scales, wind might be superior to solar by a serious margin and across a wide range of parameters.

Here's one: Nearly the entire supply chain for solar maintenance requirements is or will be in China. A heavy reliance on solar might be really bad strategic decision. It would create a never-ending dependency to China for the entire world. I don't think this is a good idea.

> Costs

I talk about this in one of my other answers. I don't think solar has an advantage here.

> We don't need a single 100% reliable source (none is), we need a clever combination of sources to achieve 100% together with the lowest total cost per energy unit.

Absolutely correct. Agreed. My argument is almost precisely in line with what you are suggesting here. Solar is 1.33 times more expensive for the same energy delivery. It requires over 5 times more land area. The factories required to build solar cost twenty times what wind factories will cost. Solar requires more than four times the battery storage systems when compared to wind (and can't deliver the same reliability at 4x). Etc.

I am thinking that we don't need a menu consisting of every single possible energy technology to make the transition to clean energy. Solar on homes and buildings is fine and very useful. Even some batteries at home might be a great idea. At grid scale? I don't know. Looking at the data I am starting to doubt that solar makes sense.

As I mentioned in another post, if we were to eliminate solar and make-up the difference with wind, you would need an area the size of Hawaii. Eliminate wind and make it up with solar, you need an area the size of 12 Hawaii's. That's should make anyone take a moment and ask: Wait, what?

Yes, other technologies are still required to get as close to 100% power availability as possible. My argument is that it might not be smart to use grid scale solar to do this.

There are two factors that you have not addressed:

- Ongoing maintenance costs (the numbers are in table 5, but essentially wind requires 2x the maintence cost of solar on shore, and the ratio is worse off shore).

- Material used in construction (table 15), the amount of concrete used is 6x greater for wind than solar. This implies a far higher CO2 cost during manufacturing. The steel used is far less for wind, I didn't see a complete breakdown of CO2 emissions for manufacturing, say per/GW of capacity.

Your overaching point seems to be that solar is not an entirely better approach than wind. But the suggestion in the plan is a mixed approach using both solar and wind. One point for comparison (made in a sibling comment) is that solar allows a more distributed approach, and a more incremental roll-out. So let me flip your point around somewhat and ask the converse: why concentrate more on wind instead of trying to optimize a balanced approach over all of the variables?

BTW, just in case people get the wrong opinion. I am NOT anti-solar in a general sense. I built a beautiful 13 kW ground-mount solar array on my property. Much of my opinion of the realities of solar is based on data I have collected and analyzed since building this system. Most people don't realize what solar can look like and assume some idealized form. Here's a quick video I made for a friend considering solar.

https://www.youtube.com/watch?v=TCyKqSmS33A

I intend to make a better video after I write some code to use the data from my system and analyze/visualize. One of the questions I want to answer is about how much storage is needed to deal with weeks of bad weather.

> Ongoing maintenance costs (the numbers are in table 5, but essentially wind requires 2x the maintence cost of solar on shore, and the ratio is worse off shore).

I actually did look at this, including reviewing the source of the numbers (link is on table 5). The way I read it is the maintenance cost is about the same.

Why?

Wind (onshore, not even considering offshore) delivers 3.07 TWh/GW, while solar only gets you 1.33. That's a ratio of 2.3.

In other words, you install 2.3 times less wind (in power rating) than solar for the same energy output.

The operating and maintenance costs are given in terms of kW per year. Therefore, when we include the fact that wind requires 2.3 times smaller installation (again, in terms of power), the total O&M cost is actually lower for wind.

Quick calculation, using 1 MW wind for simple numbers, the equivalent solar would require 2.3 MW. The annual O&M cost for each would be:

    Solar: 2.3 MW  $36,731
    Wind:  1.0 MW  $27,570

Solar, per unit power, is 1.33 times more expensive to maintain.

> Material used in construction (table 15), the amount of concrete used is 6x greater for wind than solar.

I did follow this link as well (sorry, my comment would have been a book if I included every step). Here's the source document:

https://eitrawmaterials.eu/wp-content/uploads/2020/04/rms_fo...

Table 2 (page 21), in the above document, shows that wind can be constructed with as little as 243,000 t/GW.

Table 4 (page 39), calls for 60,700 t/GW of concrete for solar. Yes, there are other numbers. They are based on the LDS/MDS/HDS scenarios as described on page 8. Frankly, some of this feels hand-wavy to me. That's just my opinion, I can't put numbers to it.

The numbers, again, are related to installed capacity in GW. Using the ratio I used above, we can then compare concrete requirements for installations that deliver the same amount of energy:

    Solar: 2.3 GW  *  60,700 t/GW = 139,610 t
    Wind:  1.0 GW  * 243,000 t/GW = 243,000 t

In other words, for the same energy output, wind, today, requires 1.7 times more concrete.

I am not sure that's a negative.

We have to go back to the idea that wind requires 5.2 times less land. Without diving too deep, preparation of the terrain and all of the activities related to construction, operations and maintenance cannot be ignored. My sense --and I have not done any calculations on this at all-- is that the actual comparison might have solar dwarf wind in terms of costs and consequences.

Going back to my prior post, full solar (no wind) in the US would require an area the size of 12 Hawaii's. The full wind scenario (no solar) only one Hawaii. Imagine trucks and heavy machinery delivering materials, transporting components, plowing, leveling, creating access roads, etc. I don't think this is a trivial difference.

However, there's another difference that I found to be shocking. I had never considered this, I guess. This goes back to the Master Plan document, table 12.

The initial investment in factories to build solar and wind are:

    Solar:  $212 billion
    Wind:   $ 11 billion

That is an absolutely massive difference and one that, in my opinion, cannot be ignored. That's nearly 20 times the cost for solar. I also wonder what the material, energy and land area utilization intensity might be for these factories.

> why concentrate more on wind instead of trying to optimize a balanced approach over all of the variables?

I don't think there's anything (physics, engineering) that requires a balanced approach, other than the obvious, which is that solar and wind need 100% backup for some portion of the energy cycle. This can be achieved through overbuilding, batteries and a few additional technologies. I am suggesting we don't need a menu of absolutely every technology in order to meet demand.

The advantages of wind, as I see them:

    - Far greater reliability
    - 4x less batteries delivers significantly higher reliability
    - 5.2 times less land area
    - 20x less manufacturing (factory build) investment
    - 3/4 the Operating and Maintenance cost of solar per delivered GWh (energy)
    - Potentially far lower reliance on Chinese supply chain

I have gone over most of these in my comments. I'll just highlight that the lower battery requirements against increased reliability is likely an important metric. The study below shows the results of looking at 39 years of data from 42 countries.

https://www.nature.com/articles/s41467-021-26355-z

Figure 2 shows that wind, overbuilt to 1.5x and with just 3 hours of storage, in the US, achieves a reliability of approximately 95%. Solar, under the same conditions, only gets you about 70% availability. In other words, you go dark 5% of the time vs. 30% of the time. That's when other technologies would have to be brought in to supplement.

Oddly enough, the same table shows what happens if you go up to 12 hours of storage. It doesn't really buy you much at all.

Neither does combining solar and wind. You gain a few percent against the case of wind only. Yet, you have to build fully two redundant systems, with solar requiring over five times more land.

That doesn't make much sense to me. When wind alone can easily get to 95% reliability with 4 times less batteries, that's got to make people take pause and possibly rethink what we are saying about solar.

For the ongoing maintenance costs I have assumed that the costs per GW are given with respect to faceplate capacity. You have assumed (or know) that they relate to the useful output. I went back to check in the source document (and in reference 41 where they originate from) but could not see a definite statement either way. Did you find something that clarified this?

That's part of the problem with some of these things, isn't it? The deeper you dig you end up with either word-spaghetti explanation or averages of averages of averages. Take this for example, from reference 41:

"For wind and solar PV, in particular, the cost favorability of the lowest-cost regions compound the underlying variability in regional cost and create a significant differential between the unadjusted costs and the capacity-weighted average national costs as observed from recent market experience. To reflect this difference, we report a weighted average cost for both wind and solar PV, based on the regional cost factors assumed for these technologies in AEO2022 and the actual regional distribution of the builds that occurred in 2020 (Table 1)."

I am not sure I have a clue what that means. And here we are, two reasonably intelligent people, trying to make some sense out of what's being presented. I don't even want to imagine how politicians or people without technical/scientific training and little interest driving them think about this stuff.

My guess: It's indistinguishable from magic. And, of course, because Elon says it, it must be correct. I don't have a problem with him. He is a smart guy, very focused and dedicated (I worked for him for a couple of years). That said, he is selling solar panels and batteries. So, yeah, I would want to really look closely and demand justification for the claims.

One can easily lie (strong word, not accusing Tesla of this) by omission, which can happen without intention. What I mean by this is that, as an example, nowhere in that document do I see a study, a comparison, of only using solar for grid-scale power vs. only using wind at grid scale. In other words, limit solar to residential/commercial buildings. I am arguing that wind at grid scale might have massive advantages when compared to solar. Tesla omitted this comparison, likely because it didn't occur to them to ask the question. At the extreme you have the "well, we sell solar panels and batteries" realization. I don't know.

The other problem I have with a lot of these papers and articles is that they use averages. The average (mean) is a fine central tendency indicator. And it is absolutely horrible for anything else. A more accurate approach divides the data into bands and studies those bands to reach a set of conclusions rather than applying a single average to the entire population.

Wind is great, and has been cheaper. Solar is overtaking though.

One key point is that solar is very predictable and pairs well with lithium ion batteries that cycle daily to meet demand for most of the globe that doesnt have dark winters.

> Wind is great, and has been cheaper. Solar is overtaking though

Understood and agreed. I am simply suggesting we might want to pump the brakes before jumping in head-first. Unless I am missing something very fundamental, wind, to me, is looking like a far better decision than solar. I am talking grid scale here, homes and buildings do benefit from solar and it's easy to deploy.

Take a look at some of my other comments for additional perspective.

One of the things that isn't in the Master Plan report is an analysis of current and future dependency on the Chinese supply chain for all of these technologies. Tesla has to tread lightly here, so, I understand.

I have a sense that the world can easily do wind with minimal, if any, input from China. This, I think, is good.

However, the real issue, in my opinion, is the operations and maintenance column. Deploying unimaginably large amounts of solar means that nearly 100% of that business will go to China. I am in manufacturing, have been all my life. One way or the other, we end-up in China. This also means that the entire world will forever be dependent on China for the ongoing maintenance of these systems.

I can't even imagine what this means in dollars per year. I think I can say it could represent the single largest transfer of wealth into one nation in the history of civilization.

I don't hate China at all. They've been very smart, worked very hard and, in about fifty years, achieved a transition from an agrarian economy to a technology superpower. This is remarkable.

My comment about dependence on China is more about balance than anything else. We need to live in a world where, well, to put it concisely, no single society has the entire planet by the balls. That's where we are headed with China. I don't think that's a good thing at all. We need to develop other areas of the world so that other societies and cultures can benefit from international trade and elevate their standards of living.

I have a feeling that mass world-wide reliance on solar will effectively shift an equally massive range of economic opportunity to China in more ways than we can imagine today.

Wind, on the other hand, I think, can be made to be far more equitable.

> One key point is that solar is very predictable and pairs well with lithium ion batteries that cycle daily to meet demand for most of the globe that doesnt have dark winters

Yes and no.

On the pairing with batteries. This is a study of 39 years of data from 42 different countries:

https://www.nature.com/articles/s41467-021-26355-z

Table 2 is very interesting (it take some effort to get comfortable with it).

One of the interesting findings is that, after overbuilding both technologies by 1.5x, wind + 3 hours of storage gets you to 95% reliability (you only go dark 5% of the time). Solar, with the same three hours of batteries, only gets you to about 70%. Even if you bring solar to 12 hours of storage, you only get up to about 85% reliability.

It is easy to understand why at a basic level: Solar is shut down half the time, when the sun isn't up. That's the baseline from which we have to start and make something that is as close to 100% reliable as possible. In other words, it's a losing proposition from the start.

My argument is only about grid scale. Local power on top of a roof is a different story. You can't have wind turbines there, solar is the only option as a supplement for the grid.

On that topic, I have noted elsewhere that I am not anti-solar at all. I am simply trying to understand if what I am observing in the data for grid scale systems is correct. I designed and built a 13 kW array on my property. Before installing this system I, as many do, saw solar in some idealized form. I guess I never gave it a second thought. Now, after many years of operating this system and viewing the data, I have a very different opinion.

This speaks to your comment about solar being very predictable. My opinion matched yours before I had solar. Today, I would say, sure, only under perfect laboratory conditions.

A friend of mine is considering an off-grid system (self sufficiency). He asked me for guidance on this based on my experience. Here's a quick explainer video I recorded for him. I didn't record this with the intent of making it a refined public presentation, keep that in mind as you watch it. The reality of solar, in this context, is likely to horrify most people who still hold an idealized view of the technology.

Again, I am not saying it is a bad technology, I am simply suggesting we are not necessarily exposing the realities that a town or city might have to content with if solar is the predominant source of energy.

https://www.youtube.com/watch?v=TCyKqSmS33A

> Solar, with the same three hours of batteries, only gets you to about 70%. Even if you bring solar to 12 hours of storage, you only get up to about 85% reliability.

I can't quickly see it in their methodology, but this feels like it's just because of the capacity factor, based on equal capacity.

You'd want to adjust for a fixed sum to spend, in which case I think solar would (these days and in sunnier places) go further. And continue to extend its lead in future.

I get your point. In fact, I think my argument aligns perfectly with the capacity factor.

Have a look at Figure 12 of the Master Plan.

The zoomed-in portion of the capacity factor very much tells a story that aligns with my observation.

If you eliminated the solar curve completely and added a bit more wind, you'd have all the energy you need. And, relatively speaking, it would be very consistent, which is one of the reasons for which I think wind could be a superior choice. Remember, we can move power thousands of miles. Wind does not have to exist near to where the power will be consumed.

I actually took the time to measure the areas under those two curves. The units don't matter (it was square cm, measured using Solidworks):

    Solar: 3212
    Wind:  6570
    Total: 9782

This is a measurement proportional to the energy produced during those days.

If we completely eliminate solar and decide to produce the same amount of energy using wind, we would have to overbuild wind by 50%. That, I think, is a fantastic finding.

Why?

Because wind can deliver far greater availability with just 3 hours of storage. Solar requires well over 12 hours of storage (and overbuild) to deliver anything approximating what wind can do with less land, less batteries. Solar requires over 5x more land, 30% more in operating and maintenance cost (per installed MW) and 20x greater investment in factories.

Put a different way: Even if you overbuilt solar by 10x, you would still, at best, have about 50% darkness (at night). Solar requires 100% backup at least half the time. Wind does not work that way, particularly if located in areas optimized for it.

That's why I am asking myself this question. Solar at home, schools and businesses, sure, no problem. I have it. So should everyone else for whom it makes sense. Grid scale? I am not so sure. I am getting the sense wind is a far, far better option for grid scale.

Once again, we should not discount the global supply chain realities. I would prefer if the energy supply chain of the future did not create a dependency on China for all maintenance from here to eternity. I think that's what we all walk into if we go solar for grid-scale energy. I have a feeling (not confirmed other than superficially) that wind provides the opportunity to globalize the supply chain and create a far more diverse distribution of wealth around the world as it pertains to building, supporting and maintaining wind power installations. That, to me, is very important. I don't think anyone is talking about this reality. I don't understand why.

Just thought of something.

Maybe the right (or the better) solution is grid scale wind with minimal storage and residential/commercial solar with some local storage. No grid-scale solar.

Why am I thinking this might be a better idea?

Well, for one thing, this, for the most part, virtually eliminates a huge portion of the materials requirements for solar installations. No concrete, except for ground mount systems like mine. From a deployment perspective, likely far less damaging to the environment all around. Going back to one of my calculations, full solar would require the area of 12 Hawaii's, while wind only 1 Hawaii.

Storage at home would also have to be nominal, just to smooth things out. Just one to three hours of storage would likely deal with most short term (24 hours) weather events nicely. Stuff like this (from my own system, due to rain and clouds):

https://i.imgur.com/breTHQd.png

Wind, combined with grid-scale storage, then become the steady and reliable backup power source. The power can come from hundreds, if not thousands of miles away. Grid-scale storage can be more localized or distributed and load-sharing across regions.

The point is to minimize the cost, material intensity, land damage and ecological impact of shifting to cleaner sources of power.

The next step would be to either have very generous tax credits for solar installation or fully subsidize it in some form. Whatever we were going to do for grid scale solar, we do to pay for residential scale solar.

One of the things that is very obvious just walking around my neighborhood is that lots of people feel no need whatsoever for solar. In a lot of cases it's retired couples of people who have very low energy footprints. Another situation is rental property. None of these cases inspire anyone to spend money on solar. That's lots of roofs, millions, tens of millions, not being utilized to contribute clean power to the grid.

This is where I see a better program in support of solar could do very well. In other words, what do we have to do to make it worth everyone's while to install solar on their roofs?

I think that's where I am with this today. Rooftop solar, installed as widely as possible. Perhaps with a small amount of local storage. Then plan on grid-scale wind with adequate storage for bulk reliable backup power 24/7/365. No grid solar.

Yes transmission is important.

Also it's unlikely the optimum will be "only technology X" wind and solar and hydro are not correlated 100% so having all will help.

For PV on homes just look at Australia:

https://cleantechnica.com/2023/02/28/nearly-1-in-3-homes-in-...

In my coutnry solar is now mandated for parking lots:

https://www.pv-magazine.com/2022/12/12/france-introduces-req...

Home and parking take zero additional land, no transmission needed.

In my town the biggest supermarket is currently covering its parking lot with solar, my estimate is that it will be 2 MW.

In a nearby city:

https://goo.gl/maps/fLb89uvZLe1iPvgV9

https://www.google.fr/maps/@43.8925214,1.8808368,268m/data=!...

> It is remarkable to me that on HN (a tech discussion forum?) the top comment on this thread is about politics. Sign of the times, I guess.

Top comment criticising Elon and using the word "toxic" says it all. It's the twitter drama bouncing back a bit.