GlobalTrvlr piscorman2 hours ago
Here is how I got to the 4x number. I am in the electricity space. I have done economics, proposals and design build for the electrical portion of projects or turnkey for every kind of generation: nuclear, coal, coal gasification, gas simple cycle, gas combined cycle, geothermal, hydro, wind, solar, diesel, and storage from pumped storage and Batteries. In the last few years I have been working on the economics of wind, solar, islanded systems, hybrid systems, etc. I know the average acreage per MW or per 100MW.
Recently, Elon Musk has been claiming that you could serve all of the power in the US with a 100 square mile plant in Arizona. The peak demand of the US has been about 750GW once a year, and as you state, you have to plan for peak plus reserve. So, if you pick texas, or AZ areas which is the most favorable place, and you use a 21% conversion of sunlight to electricity, and the given sunlight per sq meter is about 1kw. which gives .21kw per square meter. convert that to a square mile you get around 543MW. 100 sq. miles would be about 54TW. In 2023 our peak day was 750GW, and our average hourly use was 456TW. So, obviously you can't do that. So, then he also was quoted as saying he need 100 mile by 100 miles. That is not 100 sq miles, that is 10,000 sq miles. So, 10,000 sq miles would be about 540TW. So, theoretically you could run the US for the average consumption, but not the peak. If you have 38,000 sq miles, which is around 22 million acres, that would scale up to 20,500 TW, so you could power the US with that. But, not for long.
Now, those are basically using ever sq inch as a solar panel, given the spacing needs, and the needs for control houses to collect and convert, and substations and transmission stations to carry it away, you would really be down to about 60% of that. Now, given that they never run at 100% nameplate because of the temperature issues, they only have 4 hours of peak, and only about 10-12 hours of any kind of generation per day, the average output of a solar farm is 20%. Applying those numbers to the 20,500 theoretical would bring you down to about 2,460TW, so that is why I said it could provide about 3-4x what the country needs.
But, to get your mind blown, think about how many MWH of battery storage you would have to have to provide 456 TW per hour for at the minimum 12 hours, and then add in all of the solar panels you would need extra just to charge them while you are still producing 456TW/ hour to the grid during the day.
BTW, whenever you see the "could supply XX million homes" just turn your head. Those are BS numbers. It is using 100% of the nameplate rating of either wind or solar, divided by a ridiculously low average hourly usage for a home. But neither wind or solar EVER put out 100% of nameplate. Peak on wind is usually around 75% once or twice a year and averages 33% for the year. Solar can reach 80% of nameplate, but average is only 20% of nameplate. Of course both of those can go to zero, sometimes for days or over a week on end.
piscorman GlobalTrvlran hour ago
The 3.5 million homes was provided by analysts in the Biden Administration, as was the 22 million acres of solar panels to provide it. You are claiming that the Biden Administrations proposal is pure BS. I agree.
This is the gang that spend $7 billion for 7 EV charging stations.
That's great you know all of the engineering about Green Energy. You must also know about the fallacies of large-scale engineering (by the way, I've published papers in this field). But I digress.
Economic Fallacy: Green Energy is free. Yes, the availability is. So, is the availability of water, gold, silver, and other stuff. The cost is from the exploitation of the material. It takes money to get free water to the citizens of a city. So too it is with Green Energy. I'm glad you've looked at the economics.
Engineering Fallacy: This is known as the Diseconomy of Scale: because things can be built at a small scale does not mean they will scale up well. The Big Dig (a tunnel under downtown Boston for a freeway) is an example of that principle. Many Civil Engineering firms can dig a tunnel, but building one big enough for a freeway under Boston is so much different in scale as to be different in kind. The original bid was $2 billion and the final cost was over $20 billion. That will surely be the case for Green Energy.
Power Density: it takes about 100x more land to generate electricity with solar than with Nuclear. Fossil fuels are somewhere in between. The greatest demand for power is in the urban areas, where land is most expensive and least available. Therefore, Green Power will necessarily be generated away from the locations of greatest demand. This will require a significant upgrade to the power distribution systems. That's not going to be cheap.
It Looks Silly: Because Green doesn't provide energy 24x7 it must have batteries to store the power for demand when the sun isn't shining or the wind isn't blowing. It is fair to look at Green Energy as battery chargers. So, a Green Energy system will charge batteries at a remote location to transfer the electricity to a city to charge another battery. That sounds expensive. Oh, and you know this, the voltages must be stepped up for transmission. There are a whole set of circuits to be added to do this work. All of that so a solar panel can charge a battery to charge another battery at a remote location. That doesn't sound economical to me.
As an engineer, I'm sure you know that prototypes are a good way to explore options and risks to find the best way forward. California stepped up and volunteered itself as a prototype. How's that going? They are having brown outs and telling people to to charge their autos. Also, Newsom petition to keep the Diablo Nuclear facility open. It seems to me to be wise to figure this thing out in California first.
If you look at the Netherlands they are taking farm land to put these things out. If people have nothing to eat, what good is the Green Energy. So, I would strongly urge the proponents of this thing to show the rest of us what the real costs are and how it can work, by making California go entirely Green first. When that's done, then we'll be ready to take on the bigger challenges.