Good, better, best solar cells?
 

Found this chronology chart of solar cell developers & development:

http://1.bp.blogspot.com/-enKwzkcp4I...efficiency.jpg

First Solar's USA manufacturing plant is just down the road from me.

43.5%
 

Wow!!!!!!!!!!!!!
My day just got a lot better!
Delighted to see that basic research continues along with materials technology.:thumbup:
Thanks!

Theres a lot more to solar cells than meets the eye.

In addition to the efficiency you got different classes of cells. Then you have panels of different voltages. Some panels are made for 12 volt batteries, others are made for grid tie inverters and are a higher voltage.

You really need to make a chart of what you want to accomplish, then work it out. Find the most limiting factor rathers its size of the solar array, say your roof or part of a yard or budget. Then work backwards.

Lets say you are going off grid or want to knock 50 bucks off your power bill or add power to a garage or basement.

There are charge controllers and such that give the designer flexibility to choose the panels they want. The days of the "panels made for 12 volt batteries" are long past....

~CrazyJerry

In general, monocrystaline is more efficient, and longer lasting than amorphous.

The cheaper ones are often amorphous.

Amorphous may be slightly better under a partially cloudy sky.

Efficiency is sort of irrelevant. What does it cost, per delivered watt? The exception being a small roof that needs panels that are high watt per square foot.

The big companies that have been at it for a while are less likely to go out of business and stiff you on a warranty.

Wholesale solar is often very illuminating on the good deals to be had on panels.

Solar Panels from Wholesale Solar

If I could get amorphous panels for half the cost of mono-crystaline, I'd just put up twice as much, assuming both from a name brand company with similar warranties.

Ten years from now, I think it will look uneconomic to make electricity out of coal, with the possible exception of base load at night.

There's talk of .36 a watt solar panels on the horizon. If that happens, it's going to be a disruptive game changer. Hey, we can all hope.

I'd hate to see the big fossil energy companies suffer. I knew there was a fundamental sea change when traditional energy companies started buying pv manufacturers.

Efficiency is also a function of cell temperature and other conditions!

The "temperature" of the radiation coming from the sun is what, 5700K? So the highest possible efficiency of a solar cell is about 95%.

Are angle of incidence and reflective collectors considerations?

I have some mono and poly cells and the polys kick butt except in direct sun light. In those situations the monos take over, but its with the sun a perfect 90 degrees or directly over head. In indirect sun light or over cast days the polys rock.

Looks like about $1/ Watt right now.
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Astronergy CHSM 6610P 255-watt solar panel
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I am in zone 5.
4 hours of solar energy / day average. 2 hours in the winter.
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Solar Insolation Map
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I would need $12,000 in panels to charge 80 miles into a car during the winter. Versus $7 in gas. Or $3.80 from the grid. 250 round trips per year would be 12.5 years for pay back. Might be able to reduce my electric bill from surplus production on the better days and in the peak of summer. $200 per year? 10 year payback.
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Youch! A top of the line grid tie charge controller brings the 12.7kWh system to $20,000 with no batteries.
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http://www.wholesalesolar.com/system...m.html#Racking
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FWIW, I would like to see solar cells incorported DIRECTLY into the roof panels of the passenger compartment whose purpose would be to "top-off" batteries (12VDC and 240Vdc) whenever there is enough sunshine to do so.

Some of those a dollar a watt panels are expensive to get shipped. :eek:

Oh, and charge controllers, inverters, grid tie inverters also have equal idiosyncrasies in efficiency. For example the 1200 watt units are just 4 300 watt units in parallel. The 300 watt models are most efficient at about 150 watts.

Many of the devices with mppt is not able to track multiple panels, so your best bet is a 1 to 1 ratio or string the panels for a high voltage and get a matching high voltage inverter. If you string panels, make sure those are not shaded or the inverter will drop out. One cracked or weak cell in a panel can cripple or limit the over all output of the whole panel or array.

According to that, I am in Zone Two, 6.58 hours average. Inyokern is the only city rated higher, just a bit, at 7.66. They have an average high temperature of 80.833ºF. The average high temperature in Phoenix is 86.75ºF.

More sunlight, but less heat?

I cannot imagine that it is this simple, but if I multiply your $20,000 by the average of four hours of sunlight, and divide by my 6.58, would a system sufficient to provide the same amount of electricity cost me roughly $12,158?

The more important question is which ones are in production and produce the most W for the least $?

I'm in zone 6, with just 4 sunlight hours average. It wouldn't make sense for me to purchase solar at my location when there are still many homes in AZ that don't have it.

There seems to be no reason why those in Phoenix would not have solar. It would pay for itself extremely quickly. Even if the system were financed, I bet a person could be cash positive on the payments due to the offset utility bill.

Just a guess, but Inyokern is at 2500 ft elevation compared to Phoenix at 1100 ft. Holding all other factors equal, less sunlight will be filtered out by the atmosphere at higher elevations.

The elevation difference alone would account for 5 degrees cooler temps in Inyokern (assuming 4 degree drop for every 1,000 ft)

Don't let the zone map scare ya! I'm in zone #5 and year #13 now without "the line" and getting along just fine. It's kinda like doing a ecohousemodder...

~CrazyJerry

Right! Altitude! :)

The lady who watches my brother said something about it being warmer on a mountain because you are closer to the sun. It is times like that I want to ask "Have you ever even seen the inside of a classroom?"

Forget the classroom! How about a bit of practical experience hiking in the mountains? Or maybe just reasoning from observing that there's often snow on top of the mountains, but not at the bottom.

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Kinda.

In Fairbanks Alaska, people put there homes up high on the sides of the valley and not down in the valley. I was told that in spite of their homes being higher in elevation than the valley it was 20 plus degrees warmer on the side of the hill because the colder air pooled in the bottom of the valley.


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Having lived in Fairbanks, this is kinda true but not really "because you are closer to the sun".

In winter, the sun barely peeks over the horizon, especially because there is a mountain range to the south that blocks the sun when it is close to the horizon. Being on a hill can get you more daylight per day.

Fairbanks is often socked in by ice fog that fills the whole valley. This has a tendency to keep the valley cooler than up on the hills. It's also hell on your lungs.

Also, counter-intuitively, clear sunny days in winter are bitterly cold while cloudy days are much warmer...

For those of you in the zones with less direct light, you will benefit more from the poly crystals. The monos only produce in direct over head sun light.

Plan B is to use more so you make the most of the few hours you get. I tried wiring some panels in a series/parallel arrangement with a switch to take better advantage of low light. Problem is the mppt technology is a bit slow at loading up a panel for the optimum amps/volts.

Second, although the sun may seem to be slowly decreasing in brightness as the afternoon rolls on the light the panels are using for power varies. Ive seen wild variations in output for something I could not detect with the naked eye.

Same when its over cast or a brief cloud. I see wild swings in output, but nothing by the naked eye. :eek:

Electricity is dirt cheap here in the PNW and the sun is scarce. If I got solar, I would install it in AZ and write up a contract with a homeowner to pay me half the utility rate on the generated power. We would both gain more with this strategy.

That makes sense to me.

Right, it is certainly not because of being close to the sun.

Clouds trap in "the heat?"

Clouds are a greenhouse gas. Dihydrogen Monoxide should be banned.

This is not entirely correct. The manufacturing process / quality of the panel, orientation and wiring/regulation plays a big part in the overall output.

As far as "The monos only produce in direct over head sun light." That is incorrect. If this statement were true I'd be running a generator 24/7 for about 3-4 months of the year (gray-outs in the winter). I have both Monos and Polys and everyday they each send watts back into the battery bank and have for over a decade. Not being hooked to the utility line means all the pieces better work or I'm sitting in the dark; something the town goes through from time-to-time but not happening here.

~CrazyJerry

https://fbcdn-sphotos-h-a.akamaihd.n...0d07a0cf88326c

Is there a HazMat placard for spill danger?

...just like "...too much oxygen..." is poisonous to most life-forms (including humans)!

Dihydrogen monoxide:

is also known as hydroxyl acid, and is the major component of acid rain.
contributes to the "greenhouse effect".
may cause severe burns.
contributes to the erosion of our natural landscape.
accelerates corrosion and rusting of many metals.
may cause electrical failures and decreased effectiveness of automobile brakes.
has been found in excised tumors of terminal cancer patients.

Despite the danger, dihydrogen monoxide is often used:

as an industrial solvent and coolant.
in nuclear power plants.
in the production of Styrofoam.
as a fire retardant.
in many forms of cruel animal research.
in the distribution of pesticides. Even after washing, produce remains contaminated by this chemical.
as an additive in certain "junk-foods" and other food products.


Costume party last weekend (yours truly)

http://i536.photobucket.com/albums/f...psc57b3d2b.jpg

http://i536.photobucket.com/albums/f...ps8ecc4667.jpg

http://i536.photobucket.com/albums/f...ps8ecc4667.jpg

:D


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Lol!!! "Ebola Unit" - Perfect timing! That IS walking the line - awesome!!! :D

~CrazyJerry

Hah! That solves my costume conundrum. I have all of that stuff readily available. I'll have to solve the problem of how to drink a beverage, but a straw might work.

I'll take it then, that this isn't good enough for you...

:)


http://i536.photobucket.com/albums/f...ps20b85396.jpg





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And with that many panels you could for drive for 2 hours every 6th perfect day.

Excellent "proof-of-design"...now, about them acting like aerodynamic "brakes."

Clearly the panels are there for downforce. It's a race car, and the guy didn't have anything else but some solar panels laying around to make the wings.