Desert solar.

[donald]

Just to mention;


from another thread:

Same right-wing theme, it is all the fault of those nasty environmentalists. Wake up. Renewable energy, especially solar power, is safe, good for the environment and economy, and cost competitive today if all costs are included. A square 100 miles on a side in the Arizona desert could provide all the energy needs of the United States.

The largest and also one of the most efficient (per unit area covered) solar farms in the world is the Agua Celiente farm in Arizona, which delivers 630 GWh per year from its 3.75 mile^2 site.

So a 10,000 mile^2 site, on the same energy/land area basis, might produce 1,680 TWh a year from a 660 GW station. However, the US requires over 1,000 GW electricity, and over 25,000 TWh of total energy.

So, for total energy alone, it'd need to be around 150,000 miles^2 to provide the US with all its current energy. So that'd be the whole of Arizona, 113,000 miles^2 (and Arizona is a big place!) AND half of Oklahoma.

I'm not sure the terrain and weather would be particularly conducive to using the whole of those states, so maybe a third each of California, Arizona and New Mexico?

Where would you put 150,000 miles^2 of desert-sunlight solar panels in the US?

It'd need to be 200,000 miles^2 to achieve the desired power output, and it'd only be producing that for half of the day. So you'd need 400,000 miles^2. So that'd just about the THE WHOLE OF California, Arizona, New Mexico & Colorado. Assuming only a half of each of those State's land area is suitable to even mount and fix solar panels to, then it goes up to 800,000 miles ^2.

So you'd probably need ALL of the land area suitable for fixing solar panels in a total of 8 large US States. All of them, all the areas of 8 States where solar panels could be reasonably fitted.

Oh, and you'd also need about 8 TWh of overnight energy storage capability. Probably tuck that away using all of North and South Dakota with gravity storage lakes.

... so that's basically the whole of the habitable areas of 10 US states that will be filled with solar panels and energy storage sites!


Renewables will play a part in the energy mix, but only nuclear power is a viable way forward, unless overall consumption is not very heavily cut.

 

[johnrhansen]

maybe they can make floating ones. The ocean is a big place...

 

[Smidge204]

Where would you put 150,000 miles^2 of desert-sunlight solar panels in the US?

Why would it have to be in the desert, necessarily? You mention "from another thread" but gave no link...

For starters, your math skills need a little work and your actual numbers are, well, wrong.

In 2012 the US consumed about 3,600TWh of electricity, not 25,000TWh. 25,000TWh is all energy in all forms. So right out of the gate all your figures are out by a factor of about ten because you never justified making the transition from electrical power to all energy. Poor wording on the part of the quoted paragraph perhaps, but it's pretty clear from context that he wasn't talking about all energy.

Here's another way to look at it:

Per the 2010 Census, there are roughly 130 million homes in the US with an average (median) size of 1,800 sq.ft.

Let's say only a quarter of those houses - 32 million - are usable for solar energy.

Let's say only half of the house's square footage is usable - 900 sq.ft.

Let's say you get 10 watts per square foot, which includes panel inefficiency as well as area lost from racking, gaps between cells in the panel, etc.

Let's say these panels only operate for six hours a day.

These are all very conservative values. Still, 900 sq.ft/home * 32 million homes * 10 w/sq.ft * 6 hr = 1728 GWh per day, or 630TWh per year... about 15% of our electricity needs. *Just* from solar on 1 in 4 single family homes. No parking lots, no warehouses, no commercial buildings, no deserts.
=Smidge=

 

[donald]

For starters, your math skills need a little work and your actual numbers are, well, wrong.
....
Poor wording on the part of the quoted paragraph perhaps, but it's pretty clear from context that he wasn't talking about all energy.

I was referring only to what was written, which was 'all energy'. What's the point in not talking about transport related liquid fossil fuel energy use on an EV forum!?!? :?

Nothing wrong I can see with the numbers and my maths skills. You can argue the axioms on which the maths is based, but to put it in the words you did looks like a bungled ad hominem attack.

Did you not bother to try the 'search' function? - should be real easy to find key words/phrase in that quote.

I don't have a downer on solar. I like it. Should be more of it. But it seems to me to be delusionary to imagine that solar/wind/tide is enough to support a modern civilisation with the population densities of western countries. It is, in my long considered opinion, simply talk that provides bogus reasoning to discourage developing fast breeder reactors.

 

[WetEV]

However, the US requires over 1,000 GW electricity, and over 25,000 TWh of total energy.

You are getting confused about the difference between energy, heat and work.

Electric power is work. Burning coal is heat. Both are energy. Converting heat to work has a maximum possible efficiency called the Carnot efficiency, and real efficiency possible is much less.

Comparing electric power and total energy (which is mostly heat) is like comparing pineapples and oranges.

 

[Smidge204]

I was referring only to what was written, which was 'all energy'. What's the point in not talking about transport related liquid fossil fuel energy use on an EV forum!?!? :?

Again, you stripped the original quote of context. Problem is, you're STILL not using the correct numbers even if you try to excuse it like that, because it's still including energy use that is not used for transportation or electricity. And if you want to include transportation, that's fine... but you also need to adjust for efficiency, because we'd need less electricity to do the same work thanks to higher efficiency...

The forum's search is absolutely broken, BTW. You should try it sometime.

Nothing wrong I can see with the numbers and my maths skills. You can argue the axioms on which the maths is based, but to put it in the words you did looks like a bungled ad hominem attack.

You should probably reconsider what you think "ad hominem" means, especially before trying to use the term to deflect criticism. Math is more than just the algebra; it also includes proper application of the numbers.

Let's consider this:

It'd need to be 200,000 miles^2 to achieve the desired power output,

How did you get from 150 k.sq.mi. to 200 k.sq.mi? Rounding off is one thing, but a 33% increase is too much for that. I can only assume you wanted to round it off because there is absolutely no other reason for it.

Assuming only a half of each of those State's land area is suitable to even mount and fix solar panels to, then it goes up to 800,000 miles ^2.

No: Assuming only half the land was usable, you would not need to double the area. You'd have to redistribute the area, not double it. That's bad math. 800,000 should be 300,000, even if I accept all your other assumptions.

I don't have a downer on solar. I like it. Should be more of it. But it seems to me to be delusionary to imagine that solar/wind/tide is enough to support a modern civilisation with the population densities of western countries. It is, in my long considered opinion, simply talk that provides bogus reasoning to discourage developing fast breeder reactors.

Your long considered opinion is based on bad assumptions and incorrect information, that's really the crux of it.
=Smidge=

 

[donald]

You should probably reconsider what you think "ad hominem" means, especially before trying to use the term to deflect criticism.

For starters, your math skills need a little work and your actual numbers are, well, wrong.

Doesn't get more ad hominem than that. Rather than simply showing what numbers you say are wrong, the person is accused of being incapable.

Your opinions are your own. I'll not seek to debate yours.

 

[donald]

You are getting confused about the difference between energy, heat and work.
Electric power is work. Burning coal is heat. Both are energy.

I accept the rebuttal, and you've got a good point. I don't know how much of the 25PWh is waste heat and how much is primary energy. OK, maybe only 7 whole States instead of 10? What's your calculation?

 

[Smidge204]

Doesn't get more ad hominem than that.

"You are getting confused" is not an ad-hom attack.

"Your math skills need a little work" is not an ad-hom attack.

"You are an idiot" is an ad-hom attack. Notice how nobody said that...

An ad hominem is when someone introduces irrelevant critiques about the debate opponent's personal attributes. Nobody has said anything about you as a person, merely commented on your use of numbers and phrases. It's not an ad-hom just because you felt personally insulted; it's a rather specific thing.

There really are few things that drag a conversation through the gutter faster than getting hung up on things like this, but here we are... your use of the phrase is incorrect and unwarranted, and you have used it to avoid addressing the criticism put in front of you.

I'd also like to preemptively warn you against editing your posts and claiming you never said something.

If you want to know how energy is used in the US, here a good place to start. Everyone likes pretty pictures and it's a good starting point for digging deeper.
=Smidge=

 

[smkettner]

If that is all it takes.... lets get started Local solar and hydro can suppliment for the areas already occupied by a city or town.

 

[donald]

"Your math skills need a little work" is not an ad-hom attack.

It is an ad hominem fallacy. Just because my maths skills may, or may not, need work does NOT invalidate my argument. I can be the worst mathematician in the world, but still happen to get the right answer. If I were the worst mathematician ever, that still does not mean the argument I put is wrong, and therefore saying what you did was completely irrelevant to the point you were trying to make a convincing argument about. Instead, it simply leads a reader to wonder what else might be wrong about what you put.

You need to attack the veracity of what a person put, not the skills of the person who put it. The latter is an ad hominem fallacy.

 

[WetEV]

The largest and also one of the most efficient (per unit area covered) solar farms in the world is the Agua Celiente farm in Arizona, which delivers 630 GWh per year from its 3.75 mile^2 site.

Agua Celiente uses cheap cells that are 12.4% efficient. These cells are the most cost effective currently, but more efficient cells (19% to 22%) are rapidly getting more cost effective, and assuming continued use of old technology isn't useful.

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