Cleaning solar panels

[SunEagle]

Yes, it's possible to get 0 TDS by filtering only. For areas with low enough TDS, using DI resin can get it down to 0ppm TDS. But DI resin is fairly expensive. So in areas with higher TDS, RO is used in the first phase as a lower cost option to take the TDS reading down low enough (RO membranes usually has 90+% rejection ratio), then that gets fed into a DI resin cartridge to take it down to 0ppm TDS.

Sometimes if there's silicates in the water, neither the RO nor the DI will be able to filter out silicates (they're not ionically charged so DI can't trap non-ionic particles), then you can't always get down to 0ppm TDS. But if there's no silicates, it's possible to get to 0 TDS. I actually just bought an RO/DI filtering system recently and last weekend, I was able to get 0 TDS out of the system. In the window cleaning world, 0ppm TDS happens every day.

Was that RO/DI system you purchased designed for portable use with a water pole or did you modify it?

[Robert1234]

Why are you calling BS in zero TDS? Typical water from a spigot will have ~20 PPM (in my area) and much more in other areas. Filtering water to zero TDS will mean it will dry clean because there are no particles left on the surface.

The wave length I am worried about is the one that is needed to make solar panels work.

The glass used on solar panels is different than the glass used for windows so whatever testing you are doing is not very helpful. Unless you are testing multiple solar panels, side by side, with different cleaning methods on each panel with equal exposure to the sun AND tracking the output of each panel independently, you are not getting info useful to this discussion.

The small amount of TDS you are talking about isn't even going to affect the transmission of light (and thereby the solar output) by more than a few percent - if even that. I call BS because your sales pitch sounds like a snake oil salesman and your reply below just emphasized your lack of real understanding....

The wave length I am worried about is the one that is needed to make solar panels work.

Let me help you a bit so you can enhance your sales pitch to sound a bit more like real science...

Solar cells are made out of N-type and P-type semiconductor material that use the visual light spectrum to generate electricity (380 nm to 750 nm - why you think I showed you that chart ). With existing solar cells, the unused ultraviolet and infrared wavelengths are not converted into electricity but rather wasted as heat. In multi-layer amorphous solar panels, thin layers of semi-transmittal semiconductor can be applied on top of one another. Each layer is specifically doped to take advantage of a certain wavelength. Light will travel through each layer until it strikes the appropriate layer where it frees one electron and makes an electric current. This stack-up makes use of all of the various wavelengths and creates more efficient solar panels. Even more recent semiconductor materials made from indium, gallium and nitrogen can use the entire electromagnetic spectrum but I seriously doubt that the Susie Homeowner you are trying to get to pay for your service has anything like that.

I called BS because you acted like you were an expert and you infer you are more learned than the members of this forum who have time and time again truly helped me by sharing their knowledge and understanding of solar, it's use, and it's limitations. Your sales pitch is hocus pocus. You need to get an infomercial on the radio or something.... Prehaps you can model after this successfull scam organization... take this weight loss pill. It really works, but be carefull... if you loose too much weight too fast, please cut back and only take one every OTHER day.

[Robert1234]

What type of instrument(s) are you using ?

x-rite color i7

[russ]

Yes, it's possible to get 0 TDS by filtering only. For areas with low enough TDS, using DI resin can get it down to 0ppm TDS. But DI resin is fairly expensive. So in areas with higher TDS, RO is used in the first phase as a lower cost option to take the TDS reading down low enough (RO membranes usually has 90+% rejection ratio), then that gets fed into a DI resin cartridge to take it down to 0ppm TDS.

Sometimes if there's silicates in the water, neither the RO nor the DI will be able to filter out silicates (they're not ionically charged so DI can't trap non-ionic particles), then you can't always get down to 0ppm TDS. But if there's no silicates, it's possible to get to 0 TDS. I actually just bought an RO/DI filtering system recently and last weekend, I was able to get 0 TDS out of the system. In the window cleaning world, 0ppm TDS happens every day.

Sorry but I totally disagree. Filtration types.jpg

Not by filtering alone - RO does go farther but not by filtering alone.

[Volusiano]

Sorry but I totally disagree. [ATTACH=CONFIG]3864[/ATTACH]

Not by filtering alone - RO does go farther but not by filtering alone.

I guess we have to agree to disagree. You don't have to believe me, but the fact remains that I already get 0 TDS using the RO/DI filtration system I have and I see 0 TDS reading on 3 different TDS meters with my own eyes.

I know the saying that you can't believe everything on the internet either, but if you google 0 TDS water filtration, you'll find all kinds of RO/DI system that already can deliver this.

[Volusiano]

Was that RO/DI system you purchased designed for portable use with a water pole or did you modify it?

I bought a Wash-iT Pro RO/DI system from Future of Cleaning. You can assemble your own system, too, if you want. It's not rocket science. But the Wash-iT Pro has an auto-balancing system to get the optimum permeate to waste water ratio automatically without having to fiddle manually with a waste valve. And yes, it's on wheel and portable and designed for use with water fed poles. But you can use it for drinking water, too, if you want. Pure water is pure water.

[russ]

I guess we have to agree to disagree. You don't have to believe me, but the fact remains that I already get 0 TDS using the RO/DI filtration system I have and I see 0 TDS reading on 3 different TDS meters with my own eyes.That is not filtering alone which is what you said at first.

I know the saying that you can't believe everything on the internet either, but if you google 0 TDS water filtration, you'll find all kinds of RO/DI system that already can deliver this.

Industrial water treatment is an art few understand. Residential water is mostly snake oil.

The range of the TDS meters you were using is what? Are they even calibrated to analyze for zero?

Again - adding RO to filtering is a totally different game than filtering only.

[JC1]

The small amount of TDS you are talking about isn't even going to affect the transmission of light (and thereby the solar output) by more than a few percent - if even that. I call BS because your sales pitch sounds like a snake oil salesman and your reply below just emphasized your lack of real understanding....



Let me help you a bit so you can enhance your sales pitch to sound a bit more like real science...

Solar cells are made out of N-type and P-type semiconductor material that use the visual light spectrum to generate electricity (380 nm to 750 nm - why you think I showed you that chart ). With existing solar cells, the unused ultraviolet and infrared wavelengths are not converted into electricity but rather wasted as heat. In multi-layer amorphous solar panels, thin layers of semi-transmittal semiconductor can be applied on top of one another. Each layer is specifically doped to take advantage of a certain wavelength. Light will travel through each layer until it strikes the appropriate layer where it frees one electron and makes an electric current. This stack-up makes use of all of the various wavelengths and creates more efficient solar panels. Even more recent semiconductor materials made from indium, gallium and nitrogen can use the entire electromagnetic spectrum but I seriously doubt that the Susie Homeowner you are trying to get to pay for your service has anything like that.

I called BS because you acted like you were an expert and you infer you are more learned than the members of this forum who have time and time again truly helped me by sharing their knowledge and understanding of solar, it's use, and it's limitations. Your sales pitch is hocus pocus. You need to get an infomercial on the radio or something.... Prehaps you can model after this successfull scam organization... take this weight loss pill. It really works, but be carefull... if you loose too much weight too fast, please cut back and only take one every OTHER day.

What sales pitch??

I never acted like or stated I was an expert but I have been studying cleaning methods, TDS and solar panels. I came to this site to learn more about them so I can improve my business. Everything I said is true and not "snake oil" but you seem to have nothing better to do than to try and prove you are right, which you have not done...

Come to think of it, you should google "cleaning google's solar panels" and read about the tests they did.

You do what ever you want with your panels, I dont care one way or the other, its your money. Although its pretty funny watching you get your panties in a bunch, LOL

[Volusiano]

The range of the TDS meters you were using is what? Are they even calibrated to analyze for zero?

I have 3 TDS meters. One I bought from eBay, the other 2 are from Window Cleaning online stores specializing in selling water filtration system and window cleaning supplies and water fed poles. They are claimed to be calibrated. I have no reason to doubt it because all 3 meters come VERY close in their readings, ranging anywhere from 0 TDS to 2700 TDS. The 2700 TDS not a claim range but the actual reading from my swimming pool that has a salt chlorine generation system, where my salt level is 2700 ppm. The salt chlorine generator I have also reports 2700ppm on my pool water, the same level as my 3 TDS meters read out.

Again - adding RO to filtering is a totally different game than filtering only.

I don't know what you're trying to imply between RO filtering and "filtering only". My system IS RO filtering, not just "filtering only". My system is even MORE than RO filtering alone. It's a 3 stage filtering system. First water goes through a 10" carbon/sediment filter to remove sediment and chlorine, then it goes through a 4x40" RO membrane (that's almost 3.5 foot long) that has a 95%-98% TDS rejection rate, then it goes through a 20" DeIonization filter that filters out any remaining impurities left the slipped through the RO permeate output to deliver 0 TDS reading in the end.

So based on your parlance, I guess my RO/DI filtering system is definitely a totally different game alright.

[Robert1234]

Come to think of it, you should google "cleaning google's solar panels" and read about the tests they did.

I did exactly as you said, and this was the first article that caught my attention on page 1 that wasn't being promoted by the snake oil salesmen.

http://m.phys.org/news/2013-07-solar-panels-worth.html

You're certainly right on one point.... There are a lot better things for me to be doing. I thought perhaps you had some real insight that should be vetted. My assumption. My bad.

[Volusiano]

The ROI on cleaning solar panels is very subjective. There are way too many factors to consider so no one size fits all. Sometimes for homes with panels on the front roof, keeping the panels clean is not just about increasing production but also about appearance.

I've done some rough calculation for MY situation, and it comes to roughly about $1/(250W) panel/month in energy savings for ME with my on-peak rate of $0.21/kwh during the highest production month (in May) and assuming that a clean panel can produce 10% better than a dirty panel. So if it doesn't rain for 3 months and I leave my panels dirty for 3 months, that's roughly $3/panel. And this is just for summer calculation. Winter ROI is a different animal.

I live in AZ, so there can be long bouts without rain, frequent (and sometimes major) dust storms, and when it rains, it may be dirty rain that doesn't help much to clean the panels either.

The going rate for professional solar cleaning varies, too, but it can range anywhere from $2-$3/panel and this may be before a service fee of some sort (see azcleansolar.com for an example).

[russ]

What sales pitch??

I never acted like or stated I was an expert but I have been studying cleaning methods, TDS and solar panels. I came to this site to learn more about them so I can improve my business. Everything I said is true and not "snake oil" but you seem to have nothing better to do than to try and prove you are right, which you have not done...

Come to think of it, you should google "cleaning google's solar panels" and read about the tests they did.

You do what ever you want with your panels, I dont care one way or the other, its your money. Although its pretty funny watching you get your panties in a bunch, LOL

Everyone in the world has seen that blurb - been nice but bye bye.

[russ]

I have 3 TDS meters. from 0 to 2700 is not the range where the instrument will be accurate - at 0 to 5 it will be useless

I don't know what you're trying to imply between RO filtering and "filtering only". My system IS RO filtering, not just "filtering only".

So based on your parlance, I guess my RO/DI filtering system is definitely a totally different game alright.

Not my "parlance" - use the industry terms. RO is one thing and may or may not include post RO filtering. Any worth having will have pre RO filtering to protect the membrane. Most small residential units waste far more water than they purify.

Filtering alone is a totally different game.

Both have very different possible endpoints.

[Volusiano]

Any worth having will have pre RO filtering to protect the membrane.

That's why my system has a carbon/sediment prefilter to protect the RO membrane. This is just common sense. Almost all systems, commercial or residential, small or large, always have a pre-RO filtering. You will almost never see an RO system without pre-filtering.

Most small residential units waste far more water than they purify.

I would contend that not just small residential systems but ALL RO systems waste more water than they purify, commercial/industrial/residential all the same. That's just the nature of the beast. Usually waste to permeate ratio is between 3:1 to 4:1. For every permeate gallon the RO produces, 3 or 4 gallons get wasted. But small residential systems usually have an automatic shutoff valve so when the tank is full, the water inlet is shutoff and no more waste goes on.

[russ]

You will almost never see an RO system without pre-filtering. Because any sediment will clog the membrane.

I would contend that not just small residential systems but ALL RO systems waste more water than they purify, commercial/industrial/residential all the same. That's just the nature of the beast. Usually waste to permeate ratio is between 3:1 to 4:1. True for small residential systems. Wrong for higher end residential and large commercial systems are far more efficient. In the small systems it is generally because of the lower pressures.

You can get virtually zero waste systems but they have their own problems.