the dark side of PVs

[georgeodjungle]

but no seems to think on how there made.

for one 12volt 60watt panel it takes:

 2500 degrees fahrenheit then 1300 degrees fahrenheit "like glass it must be annealed"

http://www.bbc.co.uk/dna/h2g2/A912151

&

with the 20% rule of a doa panel.it takes WAY more power to make than it will ever put out, something like 400kwh @ 277volt per square meter. frame & solder not included.

&

Its a real toxic mess of chemicals. Manufactured with nitrogen trifluoride (NF3) that is supposed to be 17,000 times stronger than carbon dioxide. Solar is just not clean. Its a real toxic mess of chemicals. one square meter of solar cells carries a burden of 75 kilograms.

http://www.green-planet-solar-energy.com/nitrogen-trifluoride.html

&

when put on a tracker or concentrator yes you get more power but also shorten the life span around 40% your milage my very.

&

i'm just saying thay have this aura of green & clean after there made....

wind rules.

http://www.green-planet-solar-energy.com/nitrogen-trifluoride.html

[dbcollen]

You are an idiot, the sources you cite have nothing to do with your argument, Please stop posting this BS here.

Dustin

[Opera House]

This means we should all get our panels before cap and trade goes into effect.  That must be why there are no beer bottles, the bottles cost $50 each to make!

[Ungrounded Lightning Rod]

I see you didn't provide a link for the "more power to make it than it produces" claim.  Even if it were true (which it isn't), the same claim could be made - in spades - for grid power.

And it's an apples-to-oranges comparison:  What panels are about is delivering high-quality electricity to an end use site.  To compare to, say, fossil fuels you'd have to count the energy to make the plant, the distribution wiring, poles, insulators, transformers, etc., the crews to clear land and install them, and the carnot cycle and other losses of the generation plant and the transmission line losses.

Panels are NOT about providing electricity to be turned into heat to make more panels.  (If you really were foolish enough to use solar to build panels you could do a LOT better with thermal concentrators and the like for most of the process.)

(No time now to deal with the rest.  Some of your points have some validity.  Perhaps, now that you've provided links, others will discuss them.)

[bob golding]

seem to recall someone is using solar furnaces to make solar pv panels. cant remember the exact details. maybe unisolar?

[ghurd]

None of that is relative.

Your hangup seems somehow related to 2500 degrees Fahrenheit, which is nothing compared to the 4600 degrees Fahrenheit in an incandescent light bulb.

Think this through for a minute.

The cell manufacturing facilities pay for their electric.

They, and everyone else down the line from the wholesaler to the retailer to UPS, makes a profit.

If there is no hope of the PV making the energy it took to make, then there is no chance for payback, ever.

And since we know that is not true, then the assumptions are invalid.

G-

[mettleramiel]

You know, this is the 3rd person I've run into who says that solar panels can't make more energy over their lifetime than it takes to make them so somebody must be going around spreading this BS. The first two that I ran into told me that it would completly defy Newton's laws since you would be getting more energy out than you put into it. Obviously, they had very little understanding of basci physics.

I'm going to give you the same rough equation I gave them. If you have a 100w panel and get, say 4 hours of full sun for 250 days is one year for the 25 year that the panel is still under warranty, that would produce 2500KW. You really think it takes more energy than that to produce one panel?

[dnix71]

I'm glad the mods reopened this. It's not as open and shut as it sounds. Cadmuim Telluride is approved in the US for thin film pv, but the EU and China only allow it for export, because of the toxicity of CdTe and cadmium alone.

What happens if 20 years from now if the US reverses it's stand on CadTel? Politics and science don't mix well here. I can recycle cadmium in NiCads, or cadmium in galvanized steel because those are both common and there is commercial value in the recovery. Recycling cadtel from an old panel probably isn't worth the effort, except that tellurium is scarce.

The law here is that you are responsible for the proper disposal of anything you own. You might get stuck with an unexpected disposal cost, or sued because your recycler went out of business leaving a mess. This has happened with asbestos, arsenic and creosote.

The company I work for had warehouses full of crt's because they weren't sure who they could trust to properly handle the lead sheilding. The computers they went with were easier to get rid of because of the gold used. We still have linear fluorescent tubes piling up because the nearest trusted disposal vendor is half a state away. Compact fluorescents, on the other hand can be taken to Home Depot for free.

If CadTel is used extensively, who is going to track it? How will someone 20 years from now know how to recycle a spent panel unless they know for sure what is in it?

[Hilltopgrange]

How much energy is used to build a Wind turbine?

they don't just grow in horse manure like mushrooms! The raw materials have to be mined, processed  and transported. Steel, copper and rare earth magnets all consume vast amounts of energy to manufacture. Wind turbines also require lots more maintenance than solar!

This is similar to the misguided statement that wind turbines kill birds maybe they do but so do cars, planes and cats to mention just a few. In all the years my turbines have been flying I have not had a bird strike yet.

I don't have solar myself as we get very little sunshine but I do get loads of wind, you need to compare like with like.

horses for courses and all that.

Russell

[Ungrounded Lightning Rod]

This is similar to the misguided statement that wind turbines kill birds maybe they do but so do cars, planes and cats to mention just a few.

Large glass windows.  Territorial birds see their reflection and attack the "trespasser", often breaking their necks on the glass in the process.  Ditto flying to escape predators and hitting the "invisible" barrier at speed.

I've seen at least one (uneaten) corpse on my NV place's (Lindell Prow) rear porch, under the big view/passive-solar windows.

[scottsAI]

VERY WRONG, good example of a little knowledge makes you dangerous.

The statement is OBVIOUSLY wrong, Why?

Simple: Manufactures will not sell something for less than their cost.

They buy energy wholesale, selling me the panel at retail.

If you believe the only cost to making PV is energy you have a serious lack of understanding...

I will recover in savings MORE dollars than the panel cost me over its life. Its call payback, measured in a few years, not never.

Q.E.D.

As a Fact, PV will return manufacturing energy cost in about 3 years.

2500 degrees Fahrenheit is NOT energy, its temperature. Take a 4 inch magnifying glass, focus the sun in a tiny spot, there you have 2500F. Big deal!

C02 and toxic chemicals.

one square meter of solar cells carries a burden of 75 kilograms.

You produce CO2, to say something produces 75kg of C02 is Bad then your bad.

http://www.carbontrust.co.uk/resource/conversion_factors/default.htm

1 meter PV in AZ will produce 140w per hour per 10 hour day. Based on link, each day it will save better than 0.5kg C02. Within 150 days its Carbon debit is well paid, with the following Years to the better.

Be-careful what you read, people with a hidden agenda spew out BS frequently, passing it off as fact when its intentionally misleading or out wright LIES. Global warming comes to mind.

BTW: Wind cost energy to produce, wind is the residual of solar energy. Each technology has its pluses and minuses. To make a blanket statement wind is better, shows ignorance. Locations with NO wind its worthless, areas with NO sun PV is worthless. Wind per KW is cheaper than PV, with that said wind is a mechanical system, no 30+ years life without lots of maintenance=$. Over its life total cost on par with PV. PV produces power for decades, clean once in a while...

Have fun,

Scott.

[spinningmagnets]

I believe your statements left a few words out. For instance (paraphrased) "It takes more energy to make a PV panel, than they will produce in their lifetime"...

I disagree, but "lets just say" that your statement is true (for the sake of argument), you left out "using the processes, materials, and types of PV panels that we make today".

In my mind its like saying that the Ford Model-T only had two forward gears and a very stiff suspension, therefore, cars have no future.

Desireable products will always be sold at the prices that the market will bear (so no sudden drop in price-per-watt regardless of new procedures), but PV panels have been improved on a fairly regular basis, and they continue to evolve.

[georgeodjungle]

@ 12 volts NOT 120

[georgeodjungle]

Geeez i didn't mean to start a fight.

 just pointing out some stuff

but this is a great example.

PVS have this aura about them.

you guys have some good pionts,

 some of your math seem a lil off to.

like a 60watt 12volt panel for 4 hours can only run a, that's one only 60watt 120volt light bulb for <15 minutes.

&

the heat it takes to make one, that power comes from somewhere.shourly NOT a magnifying glass. that would be cool, ever notice the growing plants don't use PVs. it wuold take like 1,000 pvs for 1 m2 one only.

&

then there are cash cows like nellis afb:

cost $100m to save $1m ayear, but by the way the PVs last 20-30 years with out trackers or concentrators so thats a loss of $60m more or less. labor to run it not included.

http://en.wikipedia.org/wiki/Nellis_Solar_Power_Plant

&

hay i've got PVs to & vary lucky theres only a cupple days ayear when theres no wind. it's a big pic thing

[ghurd]

Our math is correct.

Watts is Watts.

Be it at 120VAC or 12VDC or 480V 3-phase, 60W is 60W is 60W.

A 60W 12V panel with 4 hours of sun will light a 60W 120V bulb for 4 hours. (ignoring inverter losses and the way panels are rated, which is not relative to the discussion)

G-

[DamonHD]

I think that claiming that you're "not meaning to start a fight" is not compatible with the social equivalent of walking into a bar on Friday evening after happy hour and telling the patrons that everything that they hold dear is wrong WHILE apparently getting basic physics wrong at the same time.

"Average" PV has had a positive EROEI (Energy Returned On Energy Invested) since sometime in the 1970s I think.  Assertions to the contrary, even invoking "big picture" mystery, do not a truth make.

So, indeed, PV isn't perfect with some nasty reagents and dopants, for example, but shall we talk about the Uranium, Mercury and other nasties in the flue gases of coal-fired electricity plants?

EROEI on PV in the UK is much less good than macro wind for example, so guess which the UK government is pushing hardest at scale?  But the EROEI of the panels on my roof is still positive AND I'm now a net generator of electricity and supplier to my local grid: no other technology is available to me in my location which allows anything like that ability to undo some of my carbon footprint.

Would you like to say something nasty about me too, throwing in a few basic errors, and claim not to be wanting to start a fight?  Please get your facts right and don't insult us with your lack of understanding.

Rgds

Damon

[Opera House]

let's use your numbers....

60W X 4 HOURS X 365 DAYS X 20 YEARS = 1.75 MWH

Just how many megawatt hours do you think it takes to make a panel?

[rossw]

@ 12 volts NOT 120

Relevance: ZERO

Your gross ignorance is showing.

I suggest you crawl back under your rock and do some REAL research. Then come back and apologise to all those you've insulted with your inane, misinformed drivel.

[TomW]

Ross;

+1

Tom

[bj]

     George--a little further down you say you didn't want to pick a fight.

Fair enough, but that's what happens when you stroll into someone else's

house and insult them.

     But all will heal, it's just one of life's lessons that we learn as we

are growing up.

[joestue]

Silion is purified by converting SiO2 into SiCl4 and purifying it as a gas and as a liquid.

Given the situation we may be in 20 years from now (either finding a really cheap alternative to current doping chemicals or their price skyrocketing) it may be economically justified to scavenge solar panels for their silicon as a starting product, and the copper, aluminum, (plastic is converted to oil first) and the rest of of the heavy metals will be removed in the same manner they are currently removed from raw material manufacture. As the density of Tellurium in solar cells is probably higher than in nature. purification and removal would be relatively easy compared to how they do it now.

The current situation is that it is not economically worth while to grind up solar cells into dust and melt it all down. It will be in 20 years, or, we will have cheaper alternatives to the current shortages of certain heavy metals.

I'm banking on the discovery of cheaper alternatives.

One of the problems with CRTs is, by the time you ship the CRT to a recycling plant, no matter how cheaply they may be recycled, you still don't break even.

In theory you might get around 5$ in recoverable steel, copper and lead.

[joestue]

The only argument you have is that the NF3 released during cell manufacture does more damage than the Co2 produced by a coal power plant over the life of the solar cell.

While the EPA doesn't have an jurisdiction over eastern block manufacturers emmissions, you really shouldn't be buying solar cells from them anyway if you live in a western state.

[morglum]

Just to add yet another comment saying the same thing, this time with a source:

Energy payback of PV Panels is 1 to 4 years, depending on technology and location:

http://en.wikipedia.org/wiki/Solar_cell#Solar_cells_and_energy_payback

[zeusmorg]

 You know,, I've always had a thing about "greenies" and "treehuggers' handing out pamphlets on saving trees,, and that live in stick and frame houses...

 Go live in a cave,, and plant some trees,, and SHUT UP!!!!!!!!!

[spinningmagnets]

You may have some useful poiints to ponder and discuss, but...

Concerning Nellis AFB, regardless of what press releases have said (you don't actually believe every press release, do you? you don't think press releases are ever used to promote an agenda?) They are not trying to save money (like Googles heavy investement in PV) they are buying independence from the grid.

Both are using todays pre-inflated dollars, and Google probably got hefty tax credits to offset their profits

[georgeodjungle]

@ 12 volt

120 volt .175mwh

[kurt]

dude first off go Google watts law and study it your argument about 12v watts being different from 120v watts is just wrong and your ignorance is showing badly. it is just making you look silly....

[mettleramiel]

Where are you getting your facts? We have already told you, a watt is a watt is a watt. It doesn't matter if you use up 100watts at 12v, 24v, 120v, or even 10,000v, it's still 100watts! The only thing the voltage would affect is the current, is that what you're thinking about?  

[DamonHD]

1. Stop trolling.

   
   

2. The difference between m and M is an error of a thousand million times.
   

[Junkie]

Didn't Homepower do an extensive article on the EROI of solar panels a few years back. I seem to remember it.

Anybody remember what it was ?