Slashing costs of the collector by ~50%

Speedy
Speedy Registered Users Posts: 11 ✭
in General Solar Power Topics #1
On my blog I have tried to do a bit of looking into the possibility of reducing the cost of the collector with sun concentrating mirrors and tracking.

Unless I have made a mistake somewhere, it seems clear that the cost can in fact be slashed by 50% or more pretty easily in a northern climate, and it's more environmentally friendly because the system has a much lower embodied energy, due to less silicon. The specific collector is of course not useful for mounting on a roof, but I was interested in feedback folks like you might have about it.


I'm really left wondering why this is not done.

Note from Cariboocoot: the linked sites run 5+ Java scripts and gave my Linux netbook fits. Proceed at your own risk.

part 1: http://towardsabettertinyhouse.wordpress.com/2011/01/28/much-cheaper-photovoltaics-part-1/#comments

part 2 http://towardsabettertinyhouse.wordpress.com/?p=999&preview=true
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  • Peter_V
    Peter_V Solar Expert Posts: 226 ✭✭✭
    #2
    Re: Slashing costs of the collector by ~50%
    Speedy wrote: »
    On my blog I have tried to do a bit of looking into the possibility of reducing the cost of the collector with sun concentrating mirrors and tracking.

    Unless I have made a mistake somewhere, it seems clear that the cost can in fact be slashed by 50% or more pretty easily in a northern climate, and it's more environmentally friendly because the system has a much lower embodied energy, due to less silicon. The specific collector is of course not useful for mounting on a roof, but I was interested in feedback folks like you might have about it.


    I'm really left wondering why this is not done.

    It's been done, however it tends to burn out the PV cells rather quickly making it uneconomical.
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  • Speedy
    Speedy Registered Users Posts: 11 ✭
    #3
    Re: Slashing costs of the collector by ~50%

    oh, okay, but I was not able to find information on the impact on panel life anywhere on the web.


    Do you or anyone else have any references for the idea that it shortens panel life?

    Especially information on how much it does so.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #4
    Re: Slashing costs of the collector by ~50%
    Speedy wrote: »
    oh, okay, but I was not able to find information on the impact on panel life anywhere on the web.


    Do you or anyone else have any references for the idea that it shortens panel life?

    Especially information on how much it does so.

    It's variable. If you concentrate light on the panels you inevitably concentrate heat. How much and how well it gets radiated off would depend on many factors. But exposing panels to higher temps shortens their life.

    Note that those of us who live in the Frozen North experience this benefit "for free"; light reflecting off Winter's snow ups the Watts and the horrendously cold temps not only allow them to superconduct but also allows any heat build-up to dissipate readily.

    You can get the same effect with reflection off beach sand (it has been discussed on this forum somewhere). But it's not very practical to run liquid nitrogen through your panels in the Bahamas. :p
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #5
    Re: Slashing costs of the collector by ~50%

    From an engineering point of view, the typical rule of thumb number used to calculate life of components based on the activation energy of materials is for every 10C increase in temperature, life is reduced by a factor of 1/2...

    If you have a 30C increase, then life is reduced by 1/2 * 1/2 * 1/2 = 1/8th the life.

    And conversely, if you run stuff cooler, you get a longer life.

    Other things that tend to limit life and increase costs:
    1. Thermal Cycling: I used to throw computer hard drives in a temperature chamber and cycle them from 40-120F a couple times a day--And a lot of them would pop parts off after several weeks (couple decades ago). Thermal cycling over wide temperature ranges (night below freezing to near 185F or more during the day is really a difficult engineering.
    2. Maximum temperatures: Regular solar panels typically have a temperature limit of 185F--The typical intensified panels (the few I have seen) are around 10x concentrators and 5x power increase... That extra heat needs to be carried off to prevent cooking of the solar cells and support hardware.
    3. Include the fact that most concentrators need trackers--that increases your costs too.
    They are already under $2 per watt for silicon panels and under $1 a watt for thin film (crystalline silicon is relatively "expensive" stuff)--Just the tempered glass, sealant/backing, copper and aluminum + handing/packaging costs are becoming significant cost factors too.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Speedy
    Speedy Registered Users Posts: 11 ✭
    #6
    Re: Slashing costs of the collector by ~50%
    BB. wrote: »
    From an engineering point of view, the typical rule of thumb number used to calculate life of components based on the activation energy of materials is for every 10C increase in temperature, life is reduced by a factor of 1/2...

    If you have a 30C increase, then life is reduced by 1/2 * 1/2 * 1/2 = 1/8th the life.

    And conversely, if you run stuff cooler, you get a longer life.

    Other things that tend to limit life and increase costs:
    1. Thermal Cycling: I used to throw computer hard drives in a temperature chamber and cycle them from 40-120F a couple times a day--And a lot of them would pop parts off after several weeks (couple decades ago). Thermal cycling over wide temperature ranges (night below freezing to near 185F or more during the day is really a difficult engineering.
    2. Maximum temperatures: Regular solar panels typically have a temperature limit of 185F--The typical intensified panels (the few I have seen) are around 10x concentrators and 5x power increase... That extra heat needs to be carried off to prevent cooking of the solar cells and support hardware.
    3. Include the fact that most concentrators need trackers--that increases your costs too.
    They are already under $2 per watt for silicon panels and under $1 a watt for thin film (crystalline silicon is relatively "expensive" stuff)--Just the tempered glass, sealant/backing, copper and aluminum + handing/packaging costs are becoming significant cost factors too.

    -Bill

    Okay, so the activation energy of some chemical reaction along the line is the limiting factor then. Something to do with the life of the silicon cells, then?

    I know that the lifetime of a silicon diode goes down exponentially with increasing temperature.

    But I figured the effect might not be too bad when it comes to the silicon cells (which are diodes), for instance, because power diodes etc are often used at elevated temperatures in the 85 deg c range, and still have fairly long lives, I think.

    Also, yes, supposedly $1/watt panels are being manufactured, in fact there are 2 thin film companies whose names I have forgotten making them for 90 cents per watt.

    But. They do not sell them to consumers, and they will not do so for many years yet, as production is being ramped up, and solar power generation stations are getting first dibs. Well, one company has a deal with "First solar" to install them on rooftops, but in that situation the customer probably does not see the savings, first solar do doubt pockets most of it.

    In the meantime, the solar panel price surveys like this one :
    http://www.ecobusinesslinks.com/solar_panels.htm

    Say the cheapest panels you can *actually buy* are $1.69. I have seen amorphous panels at $1.2, but there was no datasheet available from the mfgr (this was the purported mfgrs web site) so I do not consider those legitimate. In any case, getting the cost down is always good.

    I appreciate this information, but really need more reliable and specific (e.g. what is the lifetime they start with, 25 years is only until the output drops by 20%, not until they are fried) information, though, to be able to integrate the impact of the increased temperature into the spreadsheet.

    Does anyone have more specific information? Please please please?
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #7
    Re: Slashing costs of the collector by ~50%

    Regrettably it isn't that simple to predict. The thermal cycling Bill referred to is a mechanical process that can actually tear the panels apart. If you repeatedly heat something up and cool it down it changes the nature of the structure at the molecular level. The amount of temperature change, time held at either 'cold' or 'hot', and frequency of cycling all play a role. I've no doubt they could collect some laboratory data on this, but it wouldn't be of much use in the real world because each install would be different.

    You're not alone in your quest. Many times we've discussed here varies methods of dissipating heat from panels because that factor alone affects their output. If you concentrate more energy on them it just exacerbates the problem. Most of the "solutions" that have been examined are either unwieldy, unworkable, or just impractical (use more energy than you gain).

    So we work within the margins available, read all the announcements about "miracle breakthroughs" in panel design, and do not hold our breath waiting for the products to appear. :roll:
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  • Speedy
    Speedy Registered Users Posts: 11 ✭
    #8
    Re: Slashing costs of the collector by ~50%

    Yes, but did you actually read my post, especially the second one, which shows the suggested system?

    I produced a spreadsheet that works in a similar way to the way the System Advisor Model works, which is the solar panel power system simulator thing that Sandia labs gives out (I think it is Sandia): hour by hour simulation for a typical meteorological year.


    And first of all, without any data, not even test data for a different situation that might allow a very rough estimate to be made, I don't agree that it makes sense to assume that unassisted panels cannot be improved upon significantly.

    It is also not just about the high temperatures or heat dissipation - during winter, which is the limiting time of the year that essentially determines the size of the array you need, the ambient temperature is very low of course, providing a lot of bonus cooling. And yet light levels are low.

    Secondly, the concentration ratio can be varied, and that is very important here. During periods of low light levels, the concentration ratio can be high, getting plenty of extra power out of the panels without any high temperature issues at all.

    In fact, I can change the upper limit on the panel's temperature to 55 degrees, and I still get an improvement ratio (for the limiting month) of 2.1 or so. Which means less than half as much solar panel is needed.


    Also, we know for a fact that the payoff period of an unassisted solar array in the nevada desert is a lot better for one in Minneapolis. So if you are in Minneapolis clearly there is room for increasing the insolation without unacceptable loss of panel life.

    If there is not even any basic information on panel life vs. temperature, how exactly did you come to your conclusion that it would not work, then?

    It certainly think it is worth a shot.
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  • russ
    russ Solar Expert Posts: 593 ✭✭
    #9
    Re: Slashing costs of the collector by ~50%

    Hi Speedy - Try looking at parabolic concentrators and heliostats that use PV cells.

    What you are talking about is well documented and nothing new.

    There was a warning about your site running several java scripts so no I will not be seeing it.
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  • jagec
    jagec Solar Expert Posts: 157 ✭✭
    #10
    Re: Slashing costs of the collector by ~50%
    Cariboocoot wrote: »
    It's variable. If you concentrate light on the panels you inevitably concentrate heat. How much and how well it gets radiated off would depend on many factors. But exposing panels to higher temps shortens their life.

    Note that those of us who live in the Frozen North experience this benefit "for free"; light reflecting off Winter's snow ups the Watts and the horrendously cold temps not only allow them to superconduct but also allows any heat build-up to dissipate readily.

    You can get the same effect with reflection off beach sand (it has been discussed on this forum somewhere). But it's not very practical to run liquid nitrogen through your panels in the Bahamas. :p

    You could use dichroic mirrors to reflect only the wavelengths that are useful for producing power, which would reduce the heat concentration tremendously, and you could put your concentrators on a control circuit that would monitor panel temperature and de-optimize the alignment as needed in order to ensure that the panels wouldn't get any hotter than "naked" panels do in the summer.

    Of course, all that would probably cost about as much as just buying more panels.:p

    Not to mention that it would only work for people who don't have to submit to inspections, ie off-grid users.
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  • rollandelliott
    rollandelliott Solar Expert Posts: 834 ✭✭
    #11
    where to buy mirror film for solar applications?

    3m 330 Cool Mirror film doesn't reflect as much IR (heat), but not tested outside unprotected. 3d recommend it stays under glass.

    http://solutions.3m.com/wps/portal/3M/en_US/Renewable/Energy/Resources/Press_Releases/?PC_7_RJH9U52308NR50I0NISNKB32G3_assetId=1273668905876

    $2.32 sq feet 500 m2 minimum order over $12,000.

    http://www.reflectechsolar.com/technical.html

    0.42$ per sq/feet but requires thousands of dollars minimum order like 3M.


    http://www.greenpowerscience.com/SHOPREFLECTIVEBUY.html

    sells small quantities, but price is 6x or $3/ft2

    Anyone have experiece with any of these films? Anyone know how to get the reflectec for a cheaper price?

    please note i moved your inquiry here as it is along the same lines as this discussion. also note that pvs do use some of the infrared region to convert to electrical energy. niel
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #12
    Re: Slashing costs of the collector by ~50%
    jagec wrote: »
    You could use dichroic mirrors to reflect only the wavelengths that are useful for producing power, which would reduce the heat concentration tremendously, and you could put your concentrators on a control circuit that would monitor panel temperature and de-optimize the alignment as needed in order to ensure that the panels wouldn't get any hotter than "naked" panels do in the summer.

    There wouldn't be as much advantage to that as you might think. You'd leave out the concentrating of infrared, but the other wavelengths will still contribute to heating; the panels' increased power production also will create extra internal heat. Energy entropy is a bear!
    Of course, all that would probably cost about as much as just buying more panels.:p

    Not to mention that it would only work for people who don't have to submit to inspections, ie off-grid users.

    Yep. And there's always that ultimate law of physics and economics: diminishing returns! :p
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  • rollandelliott
    rollandelliott Solar Expert Posts: 834 ✭✭
    #13
    Re: Slashing costs of the collector by ~50%

    "Yes, but did you actually read my post, especially the second one, which shows the suggested system? "

    I kind of read through it, but honestly (dont' take this personally) it is hard to follow, it needs more photos as your explanations are kind of esoterric.

    3m makes Cool 330 film that only reflects visible light, it is about $2.25 a sq foot. Huge minimum order.

    Also I think your estimates of $70 for a rack are too low/off.

    A typical PV panel is 40x60" and weighs 50 pounds.
    if you are going to put a 60 degree mirror on each side (which it looks like based on your mock up origami sculpture) that will double your width and height. Your going to wind up with a panel that is bigger than a sheet of plywood, it's going to be heavy and I wouldn't think 2x4's would NOT last more than 5 years before getting warped and causing tracking issues.

    Better to just start out with materials that last like aluminum and that is obviously more expensive.

    that being said I do agree with your conclusion that during winter or other cold months adding more sunlight can have great benefits.
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  • Speedy
    Speedy Registered Users Posts: 11 ✭
    #14
    Re: Slashing costs of the collector by ~50%

    It is a standard wordpress blog, so I don't know why it would warn about javascripts.

    Yes, concentrated photovoltaics are certainly nothing new, you are right. That doens't mean you can't save money with them.

    In fact, that is what I am trying to find out. The only real remaining issue is to get dependable information about temperature and thermal cycling vs. panel life to verify that this approach would not fry the panels. If it does not greatly curtail the life, this approach clearly has a ton of promise.

    I know people are saying it would, but there needs to be some evidence, or it's all just Fear, Uncertainty and Doubt.


    And yes, the goal here is essentially to produce a cheaper collector for off grid use. I agree this would not be terribly useful for on grid, unless you could plonk one in your yard. Wind loading would probably make it useless for roof mount, and I say that in the post.
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  • Speedy
    Speedy Registered Users Posts: 11 ✭
    #15
    Re: Slashing costs of the collector by ~50%
    rollandelliott wrote: »
    "Yes, but did you actually read my post, especially the second one, which shows the suggested system? "

    I kind of read through it, but honestly (dont' take this personally) it is hard to follow, it needs more photos as your explanations are kind of esoterric.

    3m makes Cool 330 film that only reflects visible light, it is about $2.25 a sq foot. Huge minimum order.

    Also I think your estimates of $70 for a rack are too low/off.

    A typical PV panel is 40x60" and weighs 50 pounds.
    if you are going to put a 60 degree mirror on each side (which it looks like based on your mock up origami sculpture) that will double your width and height. Your going to wind up with a panel that is bigger than a sheet of plywood, it's going to be heavy and I wouldn't think 2x4's would NOT last more than 5 years before getting warped and causing tracking issues.

    Better to just start out with materials that last like aluminum and that is obviously more expensive.

    that being said I do agree with your conclusion that during winter or other cold months adding more sunlight can have great benefits.

    Yeah I know it is not the best blog post in the world. I would draw it in sketchup, but I'm not going to spend the time to do that until the stuff about panel life is nailed down.


    It turns out it does not double the width and height. The panel is 95 cm by 150 cm, so yes about 40 by 60. The cross sectional area of the collector when looking at it along the normal of the plane in which the solar panel is located is roughly 235 cm wide by 367 cm long so yeah it's pretty big. Yet manageable.

    I was going to put a standard size man in there for scale but forgot.
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  • Speedy
    Speedy Registered Users Posts: 11 ✭
    #16
    Re: Slashing costs of the collector by ~50%
    jagec wrote: »
    reduce the heat concentration tremendously, and you could put your concentrators on a control circuit that would monitor panel temperature and de-optimize the alignment as needed in order to ensure that the panels wouldn't get any hotter than "naked" panels do in the summer.

    Yeah, deoptimizing the alignment to reduce the concentration level occurred to me, but the thing is I couldn't figure out a very good mirror arrangement that would be able to do that without causing substantial unevenness of the radiation level on the surface of the panel.

    Unevenness is not in itsself a problem, though, just that the bright spots have to be limited to the appropriate insolation so that the tem in that area does not get too high.

    That said, yes I'm totally sure there are much better ways of doing it, and I left an open invitation in the post for if anyone else can come up with a design..... there may be designs which decide to tolerate some unevenness of the bright spots, or figure out a way to avoid them... That could get rid of the shade cloth.
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  • Peter_V
    Peter_V Solar Expert Posts: 226 ✭✭✭
    #17
    Re: Slashing costs of the collector by ~50%
    Speedy wrote: »
    Also, yes, supposedly $1/watt panels are being manufactured, in fact there are 2 thin film companies whose names I have forgotten making them for 90 cents per watt.

    But. They do not sell them to consumers,
    Umm, they are available to consumers:
    98 cents a watt if you buy a pallet

    However I'm not a fan of thin film panels. The same dealer offers Canadian Solar polycrystaline panels for
    $1.69 a watt if you buy a pallet

    A couple things to keep in mind, the power output from PV cells drops as their temperature increases. So you get a diminishing return thing going here when you concentrate the sunlight.
    The cost of 2 axis tracking will drive your price up to the same or higher than just buying extra panels.

    For example a Wattsun 2 axis tracker than can hold 1.5 kw worth of panels runs about $4,000, that works out to $2.65 a watt.
    Note that a concentrating tracker needs a higher degree of precision than a flat panel tracker and this will probably drive up the cost even more. A flat panel tracker can be off by up to 10 degrees and you will only lose about 1-2% of your power.
    If you want to have active cooling of the PV cells, that drives the cost up even more, both in dollars and in energy cost to operate.

    As far as I know every company that has experimented with concentrating solar PV has abandoned the idea for not being cost effective, and that was back when PV cells cost 3 times as much as they do now.
    The costs of PV panels has dropped to 1/2 to 1/3 what it was only a couple years ago, but the cost of tracking equipment has INCREASED. The costs of raw materials alone (steel, aluminum, etc) has gone up dramatically in recent years and this trend will continue.


    If you want a simple and cost effective way to increase the output of PV panels without degrading their life span, put them on a cheap flat panel tracker like I use.

    I get about 25% more energy out of my array, but the incremental cost of going from a fixed pole top mount to Zomeworks trackers is only about $400 each.
    So between the two Zomeworks trackers I effectively get an extra 700 watts of panels for only $800, about $1.14/watt
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  • rollandelliott
    rollandelliott Solar Expert Posts: 834 ✭✭
    #18
    Re: Slashing costs of the collector by ~50%

    "It turns out it does not double the width and height. The panel is 95 cm by 150 cm, so yes about 40 by 60. The cross sectional area of the collector when looking at it along the normal of the plane in which the solar panel is located is roughly 235 cm wide by 367 cm long so yeah it's pretty big. Yet manageable."

    If you drew a picture it might make sense, but after reading your post above and your blog post, unfortunately i do not picture what you are trying to say.
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  • Speedy
    Speedy Registered Users Posts: 11 ✭
    #19
    Re: Slashing costs of the collector by ~50%

    *bump* (hope you don't mind)

    so no one has any solid info on the impact of increased temperatures on solar panels then?
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  • rollandelliott
    rollandelliott Solar Expert Posts: 834 ✭✭
    #20
    Re: Slashing costs of the collector by ~50%

    Well that would take 25 years of testing which obviously no one has done,

    and it looks like no one wants to play guinea pig with their $300 panels.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #21
    Re: Slashing costs of the collector by ~50%

    What temperature effects are you asking about?

    Life is cut by 1/2 for every 10C increase. Power is reduced by 0.3 to 0.5% for evey 1C increase.

    For an 10x increase in intensity, there is a 5x increase in power output.

    Thermal energy radiation goes up with the 5th power increase in degree Kelvin, etc.

    Using evaporation will leave mineral deposits behind and probably etch the glass and galvanic corrosion of the frames/mounting.

    In general, materials with good electron mobility (conductors) have a good ability to transport heat. And insulators (glass, plastics used to build/seal panels) are poor heat conductors (difficult to cool).

    Water in many good solar areas is a limited resource. Cooling pipes need copper or aluminum to pipe a cooling liquid. Many areas have hard freezes and need antifreeze or drain back systems and such if water is used.

    Thermal cycling and Differential expansion (between glass and metal) will rip the layers apart over time.

    There is a lot here...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #22
    Re: Slashing costs of the collector by ~50%

    25yrs of research i'm sure has more than been done and if it what you propose was economically feasible i'm quite sure it would have been done. higher concentrations presented by the use of mirrors will destroy the lifespan of the pv in question. cooling it would help that, but that takes energy to cool it and then the aiming of the sun may also come into play with way higher costs for all of this so why chase yourselves in a circle when you can just buy more pvs?
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #23
    Re: Slashing costs of the collector by ~50%

    I think Siemens did a concentrated PV system, and had huge number of panel failures in a very short time, this on a quite big system. Every once in a while you see the panels from the decommissioned system for sale. I just missed a boatload of them for $300, with some potential unknown quantity of failed panels.


    Someone here can recall what that project was,,, I can't at present.

    Tony
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  • Speedy
    Speedy Registered Users Posts: 11 ✭
    #24
    Re: Slashing costs of the collector by ~50%
    BB. wrote: »
    What temperature effects are you asking about?

    Life is cut by 1/2 for every 10C increase. Power is reduced by 0.3 to 0.5% for evey 1C increase.

    For an 10x increase in intensity, there is a 5x increase in power output.

    Thermal energy radiation goes up with the 5th power increase in degree Kelvin, etc.

    Using evaporation will leave mineral deposits behind and probably etch the glass and galvanic corrosion of the frames/mounting.

    In general, materials with good electron mobility (conductors) have a good ability to transport heat. And insulators (glass, plastics used to build/seal panels) are poor heat conductors (difficult to cool).

    Water in many good solar areas is a limited resource. Cooling pipes need copper or aluminum to pipe a cooling liquid. Many areas have hard freezes and need antifreeze or drain back systems and such if water is used.

    Thermal cycling and Differential expansion (between glass and metal) will rip the layers apart over time.

    There is a lot here...

    -Bill


    I said the effect of temperature on panel life, but it has to be solid information, not hearsay, so a dependable decision can be made on it.


    In the help file of SAM they supply an equation that they use to determine the temperature for the panels for a given insolation, and the resulting efficiency is then computed from the information in the datasheets, which give the relevant coefficients. This is the basis for what I did with the spreadsheet.

    In other words I have the loss of performance with increasing temperature already down pat in that way. I unless I made a mistake manipulating the equations to determine the temperature as a function of the incident radiation, that is taken care of too, to an approximation that is only pessimistic (so if the spreadsheet says it works it works at least as well as it says it does).

    And yes, what you said is correct with regards to those things. And when they are taken into account, there is still a huge drop in $/watt.

    do you have any references for this assumption that the panels will be ripped apart, or the 1/2 life for every 10 deg c increase? My point is that this is not solid information which can be used to make a reliable decision.

    Also, this stuff about input increasing 5x for a radiation increase of 10x is not correct, as indicated by the graph at the top in post 1.
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  • Speedy
    Speedy Registered Users Posts: 11 ✭
    #25
    Re: Slashing costs of the collector by ~50%
    niel wrote: »
    25yrs of research i'm sure has more than been done and if it what you propose was economically feasible i'm quite sure it would have been done. higher concentrations presented by the use of mirrors will destroy the lifespan of the pv in question. cooling it would help that, but that takes energy to cool it and then the aiming of the sun may also come into play with way higher costs for all of this so why chase yourselves in a circle when you can just buy more pvs?


    Because it appears that it would work, and be cheaper, maybe even half the cost or less. According to rational analysis so far. It remains to be seen what the effect of temperature on the life of the panels is, and after that information is added to the spreadsheet a decision can be made of the impact on ROI is excessive or not.
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #26
    Re: Slashing costs of the collector by ~50%

    From a previous thread:

    http://forum.solar-electric.com/showthread.php?t=7144

    It wasn't Siemens, but ARCO solar.
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  • Speedy
    Speedy Registered Users Posts: 11 ✭
    #27
    Re: Slashing costs of the collector by ~50%

    interesting. Just googled around a bit, and found the page the carissa plant quote is from http://www.azsolarcenter.com/technology/tech-4.html

    Sounds like it was more likely the UV that damaged the panels rather than heat. However that was with the modules being produced 27 years ago. Those improvements in coatings may well have been made. Secondly this is in the desert, the sunlight is much more intense to begin with, the ambient temperature is much higher, and it is not variable-concentration ratio collector.

    And it is very sketchy information, as I said it could as well have been the UV, seems like this is hardly applicable. I have to say the idea still looks okay to me so far.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #28
    Re: Slashing costs of the collector by ~50%

    You can read about the Arrhenius equation as a start... The rule of 1/2 is one of those things that is used all over industry.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #29
    Re: Slashing costs of the collector by ~50%
    Speedy wrote: »
    Because it appears that it would work, and be cheaper, maybe even half the cost or less. According to rational analysis so far. It remains to be seen what the effect of temperature on the life of the panels is, and after that information is added to the spreadsheet a decision can be made of the impact on ROI is excessive or not.


    no it won't work and be cheaper as it will cost a small fortune and you wind up chasing your own tail so to speak. if you guys believe it to be so without the concrete proof then go for it and let us know how you do. what we say is not hearsay, but is based on many efforts people and corporations both have made. be my guest and prove us wrong for what you say is hear-say until then.
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #30
    Re: Slashing costs of the collector by ~50%

    Does it make you wonder why nobody has really done it so far? Not me!
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  • russ
    russ Solar Expert Posts: 593 ✭✭
    #31
    Re: Slashing costs of the collector by ~50%

    Sometimes when out on a boat and someone has to tinkle a short explanation is adequate.

    Others have to get wet before the leeward- windward soaks in.

    It seems people have difficulty understanding the amount of R&D effort/money that goes into these products.

    Not to mention the documentation available on the web of companies that have fallen by the wayside.

    Russ
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