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.
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:
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.
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.
- 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?