Is it practical to generate all US power by solar PV?

[Salvador]

The public can also stop consuming so much energy via substantial (even drastic) changes in life styles.

Exactly , as many are too keen on all kinds of " living for the moment" and when the majority starts to live like this not only our energy future and spending goes "bananas" but also the whole society demoralizes and economics go down.As for the investment in energy sure it needs a lot of investment.Here's the big difference and also some of the big advances and drawbacks in capitalism.You always need an investor to do something.Somehow when the US government understood that the nazis are up to getting the A bomb they didn't ask for investment nor waited for one but put in all the money and effort to just make what is needed.
I have nothing against private companies nor investors as long as they play by the rules , the rules themselves have common sense.But sometimes big projects that are not appealing in the short run but will maybe even save our civilization in the long run have to simply be paid by either government or someone with authority and knowledge.
maybe I'm biased because I come from a place were all the basic infrastructure when it first arrived as technology in the first half of the 20th century was entirely built by special state run agencies.Everything from the biggest nuke plants to hydro to the last pole with three phases running into your house was entirely state controlled as it was seen as something strategically important and so not to be given to any private companies (well there were no private companies :d)

Anyway look at projects like ITER for example , maybe even CERN although CERN is probably an overkill example for this discussion yet these big but important things are funded by states because private investors I think are too greedy and want the money to get to them in their lifetimes I doubt they care much about what's going to happen after them.P.S. @OmCheeto

I would expand on the rest of your comments, but the whores of summer are knocking on my door.

Maybe I'm not that fluent in English and I must say I have a feeling what it might mean but the way I understand it now is rather funny and seems you are living up to the expectations of Robert De Niro's latest role in the film " Dirty Grandpa" :D:D

 

[OmCheeto]

...

P.S. @OmCheeto

Maybe I'm not that fluent in English and I must say I have a feeling what it might mean but the way I understand it now is rather funny and seems you are living up to the expectations of Robert De Niro's latest role in the film " Dirty Grandpa" :D:D

Never saw the movie.
But 10 seconds after I pushed the "POST REPLY" button, someone called.
I told her that I'd referred to her as "a whore of summer".
Then we chatted for a bit, and concluded that I was also a "Whore".

ps. I'm supposed to take a bath, before arriving at her house, within the hour. If I should not respond, for the rest of eternity, let it be known, that I died, happy.

 

[Salvador]

"The whores of summer" might be a perfectly good album title for a wide range of modern pop artists starting from Justin Bieber to a guy who refers to himself as having two chains.According to him and others in the pop industry like Drake he doesn't take them off while being asleep at night.
i think there is a possible suicide by misadventure situation right there.

 

[nikkkom]

I have nothing against private companies nor investors as long as they play by the rules , the rules themselves have common sense.But sometimes big projects that are not appealing in the short run but will maybe even save our civilization in the long run have to simply be paid by either government or someone with authority and knowledge.
maybe I'm biased because I come from a place were all the basic infrastructure when it first arrived as technology in the first half of the 20th century was entirely built by special state run agencies.Everything from the biggest nuke plants to hydro to the last pole with three phases running into your house was entirely state controlled as it was seen as something strategically important and so not to be given to any private companies (well there were no private companies :d)

What makes you think it's a good idea? Did you not notice that that economic system *failed miserably*?

Anyway look at projects like ITER for example , maybe even CERN although CERN is probably an overkill example for this discussion yet these big but important things are funded by states because private investors I think are too greedy and want the money to get to them in their lifetimes I doubt they care much about what's going to happen after them.

Does ITER and generally tokamak-based fusion reactors make economic sense as power plants?

 

[Salvador]

the system failed because the very aim and goal was unrealistic from the very beginning and also the illusion that the selfish and sometimes self destructive nature of mankind can be changed by external means and force.It can't and history just has another big and thick page to prove that and it's named communism. Also remember that this whole thing incorporated in itself so many countries and nationalities that something like that is hard to keep contained even in modern Europe we see this.(although it showed that strong and one of a kind control if implemented with harsh force and authority can keep large masses contained for rather long periods of time to follow an ideology which half of them disagree with , I think we could use some of this to make up a new green and futuristic ideology to change ourselves and make this Earth better for us and the ones after us)
the only systems able to work are the ones that somehow embrace and manage to use the naturally selfish human to also bring some common good along his own selfish desires.Capitalism is a prime example of this.And even capitalism is under such a pressure to collapse and has been for so many parts of it's existence and it's all thanks to the desires and unstoppable appetite of mankind and especially those who have the money.
The world we live in now is not the one we could live in nor the best we can achieve, it's simply the best we can squeeze out of a civilization driven by selfish desire and consumerism which is balanced out with some little common sense and the instinct to survive.

No need to blindly reject and put down every single thing socialism had as some of them were advantages to both the system and mankind especially when it came to large science projects and other large scale yet very expensive projects.
many things were needed to be changed as they didn't work good enough yes surely.

That being said I don't think we should start the same political thing we enjoyed in my other thread ,I myself can write hours of world history and the way I see all of this but let's respect Jim and others who came here to talk solar panels and alternative energy.As for ITER , I think you should ask that question to the multiple scientists and people with engineering degrees that have proved themselves to the worlds largest nations to give them billions of dollars for this project.
I have an opinion myself based on both what i have read and understood but I don;'t want to get into that here as it would be sort of offtopic and rather long.
All in all it's an old soviet design picked up and refined by western scientists so both sides of the world agree it's worth to try it out on large scale. from the chorus of Eurythmics song Sweet dreams " Who am I to disagree"

 

[mheslep]

That sure beats the current estimates of $3 to $6 / watt in US.
http://www.pv-magazine.com/news/details/beitrag/us-installed-solar-pv-costs-continue-to-fall_100016490/
http://www.pv-magazine.com/fileadmin/lbnl_us_installed_costs_by_year.jpg

Hmmm stumbled across a nifty NREL site that figures numbers for your address if it's in the US
http://pvwatts.nrel.gov/pvwatts.php
here's what it says for a hypothetical 4kw system for my houseit's a cool site !

View attachment 100117View attachment 100120View attachment 100109If i converted clothes dryer and water heater to propane i might break even in non airconditioning months. My winter heat is a wood burning fireplace plus a small propane gas heater .

Even at $2.50 a watt it'd be a $10,000 investment
to unplug from grid i'd have to add BIG batteries , and maintain them
and give up airconditioning or use the little diesel generator i keep for emergency backup (and wear it out...)

Myself i think i'd rather collect solar to heat water directly , eliminating that 3.5kw load
and have a couple hundred watt panel & battery for 12V DC lights and a TV when power is off
use the diesel generator's starting battery...that way it'll stay charged...

Rooftop solar looks to me affordable for DIY'ers. As OM points out , the parts are getting cheaper. (Google returns panels for $1 a watt.)
But it doesn't replace the grid or central station generators. Yet.

Electric company still enjoys economy of scale and delivers energy dirt cheap.
I cut firewood mostly to retain some semblance of physical strength . You swing an 8 lb splitting maul for an hour and you too will appreciate that steam turbine somewhere out there, sending you hot water by wire.

old jim

Jim, your reference price includes installation, inverters, the works. I don't think $1 per W includes installation.

 

[nikkkom]

the system failed because the very aim and goal was unrealistic from the very beginning

The goal was unrealistic. You know, that's typical. The whole problem of politics is to determine which goal to set; how to detect early that a bad goal was chosen, and change course. The Soviet system was unable to do so. Free market in economics and freedom in politics are much better in this regard.

(although it showed that strong and one of a kind control if implemented with harsh force and authority can keep large masses contained for rather long periods of time to follow an ideology which half of them disagree with , I think we could use this to make up a new green and futuristic ideology to change ourselves and make this Earth better for us and the ones after us)

You come up with one excellent idea after another. Environazism is the ticket. Yes. [Sarcasm].

And even capitalism is under such a pressure to collapse

Capitalism is alive and well, while examples of socialism fail left and right (Venezuela, North Korea, Syria, Cuba).

 

[Salvador]

It seems to me that you understand the basic concepts but refuse to see deeper behind them which results in stereotypical and almost generic like answers , i am not accusing you just saying.
The idea about environmentalism isn't meant to be an ideology in itself like socialism or it's hardcore brother communism.Its just a logical way of life given that we are 7+ billion people living on a rather small planet and must somehow make it last.Much like food stamps were a logical way of life in the postwar Europe because in a total devastation you only have as much as you have and you have to somehow share that in order for everyone to get along.

You can refute some socialistic idea all you want but the modern world is such that we just have to embrace some things we dislike otherwise we will get into problems.Our abilities and resources are limited but our desire is not so something must give.

North Korea and such is not an example of socialism , you should know that , it's an example oh total idiocy by the ruling class , just because someone hides behind a label doesn't mean it has to do with the ideals and policies of that label.
Cuba was merely a satellite state the Soviets used for spying and control , so it's also a bad example, Wy don't you look at countries like Sweden for a change.

Check your PM Nikkkom as I already invited you to a private chat before.

 

[mheslep]

...You always need an investor to do something.Somehow when the US government understood that the nazis are up to getting the A bomb they didn't ask for investment nor waited for one but put in all the money and effort to just make what is needed.

The US appealed non stop for investors during the war, nearly running out of money.

...I come from a place were all the basic infrastructure when it first arrived as technology in the first half of the 20th century was entirely built by special state run agencies...

By Marxist slaves to the state. No thanks.

 

[Salvador]

calling those people slaves just because they worked in a company owned by the state is not the way it was but rather the way you were taught.
They were no more slaves than the workers that today can't make enough money to feed their family and pay the bills.
Also I know my family and trust me no one was a slave here but I totally understand your hate and I admit that the evil and imperialistic policies that have come from the Kremlin have painted both Russians and other European and Asian countries in a bad light and since I'm from Europe I also happen to be unfairly judged , but I also suspect that people reading a forum about physics should know better about history and world affairs.

I didn't know the government used private investment to fund war but I should have known better since the late Iraq and other wars have been done much the same.Although I assume they didn't exactly put up an investment offer for the " worlds first A bomb".

Just a personal sidenote , if prisoners for example are used in the construction of infrastructure like railroads etc I don't see anything bad in atleast they can give some benefit to a society they have otherwise hated and done evil against.

Ok i will have to keep out of politics in this thread otherwise I'm starting to feel guilty and bad for messing it up.
Looks like I have to open a thread in general discussion titled "misunderstandings and stereotypes of world history"

 

[nikkkom]

The idea about environmentalism isn't meant to be an ideology in itself like socialism or it's hardcore brother communism.Its just a logical way of life given that we are 7+ billion people living on a rather small planet and must somehow make it last.

If some ideas are such that you agree with them, does not mean they are not "ideology". Every set of logically consistent ideas of how to organize society is an ideology.

An ideology always looks "correct" to some people. But it may look good on paper but fail miserably when implemented in practice. Imagine that: even your, or my, ideas can be wrong.

You propose to use "strong and one of a kind control if implemented with harsh force and authority can keep large masses contained for rather long periods of time to follow an ideology which half of them disagree with , I think we could use this to make up a new green and futuristic ideology".

Why do you need "strong control"? "Harsh force and authority"? "keep large masses contained for rather long periods of time"?? "to follow an ideology which half of them disagree with"? Listen to what you are saying! That's dictatorship!

North Korea and such is not an example of socialism , you should know that

Socialism is defined as an economic doctrine where most, or even all, economic activity is performed by state-owned and controlled entities. That's EXACTLY what is happening in NK.

 

[Salvador]

I said we shouldn't have harsh control and force to push an agenda or ideology like environmentalism.Please read my posts carefully.
And also please let's talk this in private or at a different thread , thanks.

 

[nikkkom]

calling those people slaves just because they worked in a company owned by the state is not the way it was but rather the way you were taught.

In this case, the salient point is that if only state-controlled companies exist, you can't find a different employer. Because there is only one employer. Sakharov, when he become a dissident and voiced his disagreement with Soviet doctrine, found himself unable to find ANY job.

This is not exactly a slavery - the government does not own you as a thing - but quite close.

They were no more slaves than the workers that today can't make enough money to feed their family and pay the bills.

In "evil capitalist" society, you can find a different job. Or you can start your own business.

 

[nikkkom]

Cuba was merely a satellite state the Soviets used for spying and control , so it's also a bad example, Wy don't you look at countries like Sweden for a change.

I don't discuss Sweden as an example of socialism because Sweden has a capitalist economy, not socialist.

 

[nikkkom]

I said we shouldn't have harsh control and force to push an agenda or ideology like environmentalism.Please read my posts carefully.

This post?

"""(although it showed that strong and one of a kind control if implemented with harsh force and authority can keep large masses contained for rather long periods of time to follow an ideology which half of them disagree with , I think we could use this to make up a new green and futuristic ideology to change ourselves and make this Earth better for us and the ones after us)"""

 

[Salvador]

Then go and tell every American for example who is now without a job for a good reason (no drugs ,stealing etc) to simply start a business or find another job in today's complicated labor situation and see what he has to say to you for an answer.One of the reasons why Donald Trump is so popular is the very unemployment problem.Nikkkom I think we should stop this political debate here , I won't answer any more political stuff in this thread.

 

[jim hardy]

The winter months though, is why I really appreciated your link.

I think the calculator let's you adjust tilt of the panels. it set mine at 20 degrees,
I don't know whether that's off vertical or off horizontal...
and whether it's a simple default or some function of the local 35° latitude it used for local irradiance.
Might you try tilting for perpendicular to sun around winter solstice and see if winter output gets any better ?
Optimize for winter , accept a little less in summer when you don't need it ?

I'll probably experiment with tilts too, after some more cement work in the yard...

U of Florida did research on thermal collectors forty-five years ago
and concluded a DIY'ers can't beat flat plate collector with intimate contact between plate and tubes.
They used copper sheet with copper pipes soldered to it on 12" centers
because the average home handyman can solder copper but he can't weld aluminum.
4 X 12 feet makes plenty of hot water for a family of four in Florida.
Does it ever freeze where you live? If not , consider replacing your water heater with a flat plate collector & elevated tank for thermosiphon .

Zero moving parts, zero maintenance.
Doesn't make kilowatts but displaces them with zero complexity. No electronics.
At a conservative 100kwh/month for two people(most water heater estimates are twice that see https://www.keysenergy.com/appliances.php )
and 15cents/kwh = $15/month
a thousand dollar homebuilt would pay back in 5.5 years vs ten for PV

this is not a hijack - a kwh saved is 3412 BTU's earned.
Save that beautiful electrical energy for more noble things than heating water - like posting on PF.

old jim

 

[Salvador]

what do you think Jim , is a solar collector more efficient than a heat pump/exchainger, I'm not sure how to call them , you know the ones that work after the same system a fridge uses , were one part of the piping is set underground outside. ?
I think it counts partly as a renewable since the heat underground comes from Earth and sun combined and we invest only in the electricity running the pump which then pumps the working fluid.

maybe we should make solar panels that have both the cells that generate electricity and some water piping beneath them , and so for a larger array one would get out direct electricity + heated water which could then be used to either heat homes for those who live in colder climate or other needs.Although I'm not sure about the efficiency of such a proposal , I assume that infra red is harder to convert to electricity than the other wavelenght's in the sunlight.
I read that newer panels promise to convert much more of the spectrum that has some significant power in it also including infra red.

 

[jim hardy]

what do you think Jim , is a solar collector more efficient than a heat pump/exchainger, I'm not sure how to call them , you know the ones that work after the same system a fridge uses , were one part of the piping is set underground outside. ?
I think it counts partly as a renewable since the heat underground comes from Earth and sun combined and we invest only in the electricity running the pump which then pumps the working fluid.

If you take the physicist's meaning of efficient, useful output / input,
then a heat pump has to count the energy extracted from the ground as part of the input. The electricity to run it is the rest.
That's because any heat engine has to be less than 100% efficient (unless it can reject heat to absolute zero) .

But if as a layman i just want to get the most heat for my money
My heat pump delivers X BTU's to my hot water tank for Y kwh of electricity, and my layman's efficiency is X/Y .
(when corrected to get same units in numerator & denominator)
But a solar panel with thermosiphon runs with zero electric input so my layman's denominator is zero giving it layman's efficiency of ∝.

In a strict scientific sense that's lying with statistics. But it's what matters where the rubber meets the road., my checkbook .

Common sense says if i don't have to run electricity to it or fix leaky pumps or microcontrollers that succumbed to lightning strikes
now THAT's life cycle efficiency

https://en.wikipedia.org/wiki/Solar_water_heating

A laundromat in California with panels on the roof providing hot washing water.

sixty percent-ish ? As a physicist you get 0.6 BTU's for every one that fell on your collector as sunshine.

Now to that heat pump
An EER of 20 for a really good unit would be in terms of my "layman's efficiency" , heat delivered / work bought from electric company
EER is BTU's (per hour) delivered per watt of electricity, Layman's efficiency if you will ..
20 BTU's per watt hour = 20,000 BTU's per kwh
Now a KWH is 3412 BTU's...
meaning you get from that EER 20 heat pump 20,000/3412 = 5.86 times more energy than you paid the electric company for. 4.86 of them came out of the ground... but does my checkbook care ?
Beats plain old water heater, eh ? It gives you 1::1 heat delivered/heat bought.

It appears to beat the solar panel, too. 5.86 heat units per unit bought vs 0.6 heat units per unit of sunshine
but remember you put zero kwh of electricity into the solar panel...

It helps to get an intuitive feel for heat.
A BTU/sec is within ~5% a kilowatt, (1BTU/sec = 3600BTU hr / 3412 BTU/kwh = 1.05kw)
That's about the output of one stove burner on high setting.
And it's also roughly the sunlight falling on a square meter of earth.
(http://education.gsfc.nasa.gov/experimental/July61999siteupdate/inv99Project.Site/Pages/science-briefs/ed-stickler/ed-irradiance.html )

Stick to your basics... complex things are just an assemblage of simple ones.

old jim

 

[anorlunda]

@jim mcnamara

I don't understand the foundation of your disagreement in #119, unless you confuse what I said about investors with the phrase "investor owned utilities" IOU. They are very different things.

Municipals and coops have private investors who purchase their bonds. Municipals bonds alone in 2011 were $3.7 trillion. I was not able to to find the number for coops. Having private companies insure privately owned bonds does not shift the public/private mix of finance.

In post #118, I was talking about public versus private investment sources (i.e. taxes versus all other sources of money). That has nothing to do with IOU/municipal/cooperative kinds of utilities. The reason I mentioned it was to counter the widespread public belief that they can dictate the energy future at the ballot box. That IMO is incorrect.

 

[Salvador]

It's hard for me to follow you Jim especially with all those BTU's and stuff I'm not sure if it's the SI system or the older one that the US uses.

https://en.wikipedia.org/wiki/International_System_of_Units#/media/File:SI-metrication-world.png

P.S. I wonder if the American settlers so hated the imperialistic British empire then why did you kept their old measurement system.I think the SI system is easier , yes I know it's a biased opinion but still it feels easier, much like I would love the world to speak just one language and I have to admit English is the easiest for me , so many problems would go away and we could make progress faster.

As for the heat pump I got the main point , well you can always use a solar panel to be your " excitation" power source together with a few wind blades in case sun doesn't shine usually wind blows then.You can use that electricity to power your low power applications and leave the rest for the heat pumps motor and then the heat pump takes the high power applications replacing them with natural heat from earth.After all the most consuming electrical applications nowdays are the ones that have to produce heat , like electric heating, ovens and cooking stuff , water heaters etc.Basically everything with a large resistor inside.
Maybe it's not so much of a problem for you if you live in warm climate but where I live we still get winters , much different than the ones my grandmother used to recall so I can confirm climate is changing but they are still there so in winter almost 3/4 if not more of my bill go for heating.
And since I have an electrical water heater that part goes around the year.So basically most of my electricity bill is for heat.

I agree with what one of you said earlier that we must diversify the renewables , not because it's simpler no it's not , it's more complicated , also it's not cheaper but it's simply because with renewables you don't get enough power out to simply take one and leave it there , it's not a nuke plant that gets the job done for a middle sized city easily.So we must use many different alternatives that all give us the same end result.

P.S. when I write the word renewables the system puts a red line underneath the word but I checked and I think I'm writing it correctly so what's wrong with the red line ?
Could it be that physics forums software isn't friendly to renewables ? :D:D Whenever I write words like big nuclear plant or fossil fuels they aren't labeled red :D

 

[jim hardy]

(post 126)
Jim, your reference price includes installation, inverters, the works. I don't think $1 per W includes installation.

Yes, the dollar a watt was for just a panel , for DoItYourself-ers.

Bauncore i think said $1Au in his part of the world included installation.

As far as i can tell, the cited cost where i live includes your tax credits and gov't incentives, so up-front out of pocket cost is likely a lot higher. In Florida i inquired about a "free" solar system. Yeah, $6000 now to them and "You'll get it all back when you file your taxes" . Buyer beware.
old jim

 

[jim hardy]

It's hard for me to follow you Jim especially with all those BTU's and stuff I'm not sure if it's the SI system or the older one that the US uses.

Sorry for that

i hope i didnt drop a conversion factor someplace
A BTU is the heat to warm one pound of water by 1 degree F ...
so it's a unit of energy just like a joule.
in terms of F X D it's 778 foot pounds
which should be easy to convert to SI,
using estimates from our everyday experience
we know from a coffee can that a pound is 0.454kg,
and we remember from Physics class that 9.8 gets us from kg to Newtons (edit at standard gravity)...
Does a "Quarter Pounder" hamburger weigh around a Newton ? Maybe 1.1 Newtons ?

that's why Electrical Engineering is easy and Mechanical Engineering is difficult - our units are already metric, Volts Amps Ohms, Joules and Watts.
I always pitied Mechanical engineers for their Ohm's Law requires square roots and Reynolds numbers.

That's why long ago i latched on to these two memory aids
"A BTU per second is within 5% of a kilowatt"
and in power plants where we produce and track heat but sell it as electrical energy ,
" 3412.7 BTU's = 1kwh" is as basic as gravity.

from those memory aids and 2.54 cm to the inch one can figure out any other units

and that's what EER rating does for people, converts units
tells how many BTU's a heat pump moves per watt-hour. That's units of energy moved per unit of energy put in.
And you don't have to be a physicist to know 10 is so-so, twenty is great and 5 is terrible.

With so many units named after long gone scientists it is difficult to keep straight whether one is describing energy or power.
I understand your plight, been there and still stumble especially if I'm trying to hurry.

If i made a mistake please point it out and i'll correct it.

old jim

 

[anorlunda]

I come from a place were all the basic infrastructure when it first arrived as technology in the first half of the 20th century was entirely built by special state run agencies.Everything from the biggest nuke plants to hydro to the last pole with three phases running into your house was entirely state controlled as it was seen as something strategically important and so not to be given to any private companies

I think you are confusing ownership with source of financing. If you go back and check the history of those government project you mention, I'm confident that you will find that they were largely financed with bond sales to private investors.

It was those private investors that I referred to in #118. They were not compelled to buy the bonds, and if they did not believe in the projects they would have put their money elsewhere.

In 1983, Washington Public Power System (WPPS which I pronounce as "whoops") defaulted on their municipal bonds for the Satsop Nuclear Power Plant. In the USA, that event changed forever the scrutiny given to government utility bonds. A portfolio manager could be guilty of malpractice if he invested private money in government bonds for an unsound project. It happens every day that proposed projects are canceled because they fail to attract sufficient financing. Those cancellations may make no news or are reported in an obscure item on page 22c of the newspaper.

I stand by what I said. Large scale electric infrastructure projects. public or private, require private money to finance them. The private investors have the final say over whether to invest their money or not.

There may be TVA or BPA employees reading this thread. Perhaps they could tell us if their organizations do or don't raise money selling bonds.

 

[IllyaKuryakin]

Quite simply, no, we can't produce all our power with PV. The reason is that the sun doesn't shine at night and there is no practical way to store enough power to get us though the night. The efficient combined cycle power plants or nuclear plants take days to start up, so they can't even be shut down during the day when the sun does shine and provide needed power at night. All PV can do is offset the "Peak" power plants that start up quickly to provide peak power demands during the day. That amounts to no more than 10% of total power production.

 

[nikkkom]

Quite simply, no, we can't produce all our power with PV. The reason is that the sun doesn't shine at night and there is no practical way to store enough power to get us though the night.

No, there are many ways to store energy. Some are in use even in todays power grid.

 

[IllyaKuryakin]

No, there are many ways to store energy. Some are in use even in todays power grid.

Yes, I agree, there are many ways to store energy, but none can cost effectively store the amount of energy needed to get us through the night. Sorry, that's just a fact. Do a bit of research into the matter as I have and I'm sure you will reach the same conclusion. Now, if you create a cost effective way to store vast amounts of electrical energy, not only will we be able to use PV to generate all our power, but you may become the worlds first multi-trillionaire. So, I'll be very nice to you, just in case you are successful :-)

 

[nikkkom]

Yes, I agree, there are many ways to store energy, but none can cost effectively store the amount of energy needed to get us through the night. Sorry, that's just a fact.

Cost-effectively? This thread's title is not "Can battery-backed energy storage be on par with current coal and gas plants?"

I am sure it would be more expensive. The question is whether it's practically possible (and I might add, without drastic measures such as diverting entire world's lithium production into batteries production for decades, or making electricity permanently x20 more expensive, or something like that).

Looks like it is possible. Many battery types exist, we are not limited to expensive lightweight ones. Sodium-Ion, good old Lead-Acid, Sodium-sulfur, Ni-Cd, Al-ion. New types of batteries are being looked at.

Even now people build huge batteries, such as 400MWh, and not because they are nuts and want to build something uneconomic. Evidently, it is _profitable_:
http://www.utilitydive.com/news/5-battery-energy-storage-projects-to-watch-in-2016/409624/

 

[bob012345]

In another PF thread it was proposed to build a centralized PV farm of 1000 gigawatts , which is the order of magnitude of US installed generating capacity. It'd cover 1/10 the area of New Mexico, Arizona and Nevada.

√ (10%of 896815 km^2) = 299.5 km per side, 186 miles per side, not far from the 150 stated earlier in the same thread.
Close enough for thought experiments.

You can't drive maintenance trucks over solar panels so the dimensions will expand to accommodate roadways.
Unless they're elevated to serve as rooftops with access from below.
Stormwater runoff from a 150 mile square rooftop will be a challenge, Phoenix area has been known to get 6 inches in a storm.
http://www.fcd.maricopa.gov/Weather/Rainfall/raininfo.aspx

It'd be interesting that's for sure.
Myself, i am far more afraid of huge storage batteries than of reactors. I wouldn't be go anywhere near them.

Maybe @anorlunda will assess the practicality of moving so much power over so much distance.

The answer is no. It is not practical nor wise to embark on such a massive project which assumes natural solar is the best and only solution, which it is not. Encourage development with tax policy and let the markets decide how to provide power.

 

[mheslep]

...
The question is whether it's practically possible (and I might add, without drastic measures such as diverting entire world's lithium production into batteries production for decades, or making electricity permanently x20 more expensive, or something like that).

Looks like it is possible. Many battery types exist, we are not limited to expensive lightweight ones. Sodium-Ion, good old Lead-Acid, Sodium-sulfur, Ni-Cd, Al-ion. New types of batteries are being looked at.
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An all solar US is *not* practically possible using only battery backup, for exactly the reason you suggest (at least). This limitation has been addressed earlier in the thread. There is not enough lead, not enough lithium produced in this world to build the hundreds of TWh required, nevermind replacing it every half dozen years or so. Basic assumptions and facts: 336 billion kWh of storage required with 15 kg of Pb per kWh is 5 billion tons of Pb. Global reserves of Pb are 80 *million* tons.

http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-battery/

This calculation on storage is not really necessary, and the order of magnitude mismatch somewhat predictable, if one looks first at the enormous size of existing coal, gas, and oil production, just the volume and mass of hydrocarbon. Or, see the scope of world's existing hydroelectric dam capacity, though it supplies only a dozen percent or so the world's electric power.