Thomas Allen Schmidt's posts

I hope you do not take offense Mike but reading these posts in your thread is lot like seeing a little kid turned loose in a candy store.
I want to remind you that PV modules are all about electricity and if its not conducted properly it can cause serious damage, not just to yourself but there is always potential of harm to others.
Moderation, self control, common sense.
Common sense, there is a phrase that I think a lot of people have lost touch with its true meaning in the text for which it is intended. 
The NEC is, I think, more about possibilities than probabilities. Thats to say, the worst may not ever happen but it can happen, so prepare for it as though it will happen. Electricity can be a harsh mistress.
Gotta go!

One thing I can tell you that is for certain, none will last for ever and you will learn quickly what works and what doesn't and how to get your moneys worth.
I started out just plugging the house up to a receptacle installed in the front of my truck. It powered nothing more than a few incandescent 12 vdc bulbs and I learned how many lights and how long we could use them and still be able to start the truck in the morning. Fortunately there is a small hill in our drive from the house. Auto cranking batteries lasted about 4 months like this.
Gradually this evolved into the installation of a battery isolator and a 12 volt marine deep cycle battery and a small on board inverter. So I was plugging up to the truck but it was 120 vac now and a few more loads in the house. These batteries lasted about two years.
Then came the PV modules and large 8D big rig cranking batteries and the truck power was done away with. These 8D's lasted a year.
More PV and Trojan T-105's. I managed to squeeze 7 years out of those. During this time even more PV was added.
We are now living with Surrette 530's. I hope to squeeze 25 years out of them.
There would seem to be some truth to the old addage: "You get what you pay for."
In anticipation of the next set, this is what I have been considering.
http://www.beutilityfree.com/content/index.php?option=com_content&view=article&id=44&Itemid=129
If I only knew then what I know now. This might sound like regret, but I had lived without any electricity for nearly twenty years before wiring that receptacle to the front of my truck. So I can take it or leave it. Despite what some may have to say about it, I know for a fact that life is possible without electricity. In a lot of ways, I think it was better. It would be difficult to retire my off grid PV system but I could never retire from my off grid life.

This is from the 2002 NEC. The NEC is revised every three years.
http://photovoltaics.sandia.gov/docs/PDF/PV_grounding_CC_HP_102.pdf

I grew up hearing a phrase, "You've opened up a can of worms." As a child I imagined that worms came in a can and on those occasions that I went to the grocery store with my mother I would look for them on the shelves of canned goods. Of course I never saw them. Eventually though, on a summers fishing trip with my dad and a bucket of worms, I caught on to its meaning. A tangled mess. You can't tell where one worm ends and another starts.

Electricity is a simple matter to some and not so simple a matter to others. A never ending circle of events. For most, I believe that, as long as the light comes on when they flip the switch, thats all that matters.
I would explain electricity as, an amount of electrons over a period of time, but it can go a lot deeper than that. What is an electron? What is time?
What is an electron? For that we have to look at the atoms of matter or a mass.
So what are atoms made of? In the middle of each atom is a "nucleus." The nucleus contains two kinds of tiny particles, called protons and neutrons. Orbiting around the nucleus are even smaller particles called electrons. The 115 kinds of atoms are different from each other because they have different numbers of protons, neutrons and electrons.
http://www.chemicalelements.com/
Protons, neutrons and electrons are very different from each other. They have their own properties, or characteristics. One of these properties is called an electrical charge. Protons have what we call a "positive" (+) charge. Electrons have a "negative" (-) charge. Neutrons have no charge, they are neutral. The charge of one proton is equal in strength to the charge of one electron. When the number of protons in an atom equals the number of electrons, the atom itself has no overall charge, it is neutral. 
Some materials hold their electrons very tightly. Electrons do not move through them very well. These things are called insulators. Plastic, cloth, glass and dry air are good insulators. Other materials have some loosely held electrons, which move through them very easily. These are called conductors. Most metals are good conductors.
This is where the question, what is time, might occur.
We cannot conceive of motion without time. Clocks measure time. We cannot conceive of time without motion. When there is an imbalance of electrons between to atoms, the electrons will move (motion/time) from one to the other in order to balance out. We see this in nature as static electricity and on a larger scale lightning.
 A coulomb of negative charge is that of 6,280,000,000,000,000,000 electrons.
One ampere flowing for one second of time passes a coulomb of electric charge. Charles Coulomb first described electric field strengths in the 1780's. He found that for point charges, the electrical force varies directly with the product of the charges. In other words, the greater the charges, the stronger the field. And the field varies inversely with the square of the distance between the charges. This means that the greater the distance, the weaker the force becomes. This can be written as the formula: F = k (q1 X q2) / d2
Where F is the force, q1 and q2 are the charges, and d is the distance between the charges. k is the proportionality constant, and depends on the material separating the charges.

One could expand on all of this and theorize that, energy is equal to mass but only at a certain speed, the speed of light squared: E=mc2.
It can be construed that energy and mass, mass and energy are one in the same.

"The human mind is not capable of grasping the Universe. We are like a little child entering a huge library. The walls are covered to the ceilings with books in many different tongues. The child knows that someone must have written these books. It does not know who or how. It does not understand the languages in which they are written. But the child notes a definite plan in the arrangement of the books---a mysterious order which it does not comprehend, but only dimly suspects." ~ Albert Einstein ~

Have you ever notice how, sometimes, you can hear something said or read something written a certain way and it seems to turn a light on inside your mind? I think its called an epiphany.
Batteries were a big mystery to me at one time until I read in an old high school science text book that, "Batteries do not store electricity, they convert electric energy into a chemical energy and store that until such time as the electric energy is needed and, then it is convert back from chemical energy, with a cost."
Some folks think in terms of text, some in terms of math, I think in terms of images. When I read this about batteries, I could visualize, with my minds eye, what was going on inside the battery at the molecular level.
In the lead-acid battery, the active material within the positive electrode consists of lead dioxide, while the negative active material is a metallic lead. The positive active material is formed electrochemically from a cured plate, and influences the performance of the lead-acid battery. The electrolyte consists of a sulfuric acid solution, and as the battery discharges, the electrodes are converted into lead sulfate, which reverses when the battery is charged.
The basic principle behind "the battery" is two dissimilar metals and a catalyst. That was discovered by Luigi Galvani sometime in the 1700's while cutting a frog leg, Galvani's steel scalpel touched a brass hook that was holding the leg in place. The leg twitched. Further experiments confirmed this effect, and Galvani was convinced that he was seeing the effects of what he called animal electricity, the life force within the muscles of the frog. At the University of Pavia, Galvani's colleague Alessandro Volta was able to reproduce the results, but was skeptical of Galvani's explanation.
The Voltaic pile. A century and a half after Galileo's death, something of scientific importance was to develop in Italy. Volta, a former high school physics teacher, found that it was the presence of two dissimilar metals, not the frog leg, that was critical. In 1800, after extensive experimentation, he developed the voltaic pile. The original voltaic pile consisted of a pile of zinc and silver discs and between alternate discs, a piece of cardboard that had been soaked in saltwater. A wire connecting the bottom zinc disc to the top silver disc could produce repeated sparks. No frogs were injured in the production of a voltaic pile.

I realize this does not help you to fix your immediate problem. If anything it makes it worse because your here, using power to read my trivia. Actually, I think Mr. Owens has a good point in that regard. Lets us know how it all turns out, won't you?
 
F = k (q1 X q2) / d2  (Charles Coulomb)

I am going to ask you some questions. They may come across as being offensive. Especially so, being written on a public forum, so please, don't take offense, its not intended. It would be different if this were person to person or better yet, friend to friend, right?

Is this the first time you've added distilled water in a year and a half?
Are they getting a good charge?
These two question kinda go hand in hand, if you know what I mean. Is the charge/discharge cycle, in amp hours, they receive over 24 hours approximately 1/5 of the total rated amp hours of capacity? I guess a better way to ask that would be, are they being shallow cycled or deep cycled?

You did use distilled water?
Had the battery bank been equalized before the addition of new distilled water?
Before distilled water was added, were the plates exposed to air?

Once the distilled water is added into the battery it mixes with the acid and becomes electrolyte.
To much electrolyte will start to rise as charge develops and could come out of the batteries, spilling out all over the place or worse, if the cap gets full of electrolyte, the gas may not be able to escape fast enough and it could blow the caps off. It wouldn't be a bad idea to remove some as you suggested. Save the electrolyte though and add it back next time.

"Walking with a friend in the dark is better than walking alone in the light."
~Helen Keller~

I have always equated cheapness with lack of quality. But I know what it is your asking. It would seem that cheapness has become synonymous with being inexpensive, as has quality with expensive. But enough with the semantics.

I take it that the turbine will turn pretty much non stop, producing power non stop unless acted upon by an external force. This being the case, a load diversion regulator could be made relatively inexpensively. It sould to be able to monitor battery voltage, high and low as well as trigger a relay transfer. Any number of loads could do the job from 12 vdc water heater elements to 12 vdc incandescent light bulbs. What happens though if a light bulb blows? I don't want to take all of the fun out of it so I'll provide a few links to hopefully get you started in the right direction.
http://www.survivalunlimited.com/diversionloads.htm
http://www.fieldlines.com/
This last link has tons of info but it may take some leg work or, maybe I should say "finger" work? No, something doesn't sound right about that. I am gonna stick to leg work. Anyway look closely, there are links to other links and so on and so forth. Good luck!

What Ken describes makes sense, although the technology doesn't.
Assuming that its 12/2 with a ground Romex wire from the inverter to the panel, just for clarity, you're saying Ken, that these inexpensive half voltage scheme inverters are sending out half the voltage, 60 vac, on the black wire and the other half of, 60 vac, on the white wire and they come together in the load making the full 120 vac? (Which in Mike's case the white neutral wire is bonded to the bare grounded wire or EGC in his panel and 60 vac went to Earth and everywhere the EGC goes.) Yikes!

Would you tell us, what is the advertised trade name for this technology Ken?
I know there is; true sine wave, modified sine wave, and square wave inverters on the market.
How can someone know if they are buying an inexpensive half voltage scheme inverter?

One would think that with over 7,000 years of practice the human race would have "it" all figured out by now.
What is "it"?
Life on Earth of course! What else is there for us?

We have all heard the stories, the tragedies involving; planes, trains and, automobiles; boats, buses and, rocketships. Take the lastest Metro train collision for example.
http://www.msnbc.msn.com/id/31495088/ns/us_news-life/
 The authorities have yet to ascertain the reason or reasons for the crash yet. There is speculation that the trains are aged and in need of retrogrades or replacement. Obviously if they are computer controlled then it was the computer that put them on a collision course to start with. Then there is always the chance of "pilot error" or in this case "brakeman" error.
Any way we look at it, its human error.

Take a look at this and ask yourself this question.
http://www.babcock.com/products/modular_nuclear/
Do we really need a gypsy with a crystal ball to fortell a future event?

I suppose I will just have to wait and see. Pray that it doesn't happen to me. That is what we do right? At least that is what I am accustom to witnessing most other people do. It would seem to be the norm.

It would seem to me sometimes that, whatever divine power there is in the universe that decides the fate of mankind, that this entity, has been lenient with mankind and has given us a life sentence on Earth with all of the delights of nature. Of sunlight and air and rich biodiversity. But we have chosen to commit suicide. Oh, not in one decisive stroke like jumping of a high rise our putting a shotgun in our mouth, but self termination all the same.
Pity about Earth.

Ya, codes can be a hassle sometimes. Its for a good reason though. I think it has something to do with the "Riot Act." You know, "If we let one person do it then everybody will want to do it and the next thing you know we have a riot on our hands." I am not sure how its on MA but in NC they all fall into the hands of "the Authority having Jurisdiction."
Even national codes.
Which is to say a city inspector might have a different perspective than a county inspector and so on and so forth.
Even city to city. A metropolitan area might stricter on somethings than a smaller city.
A local contractor would be able to answer your questions better I think. Hold on... That darn cat keeps getting out of the bag. Ok, where was I? Oh yeah, contractors of all sorts here in NC must be licensed and have there work permitted and inspected so they would know better than most what the inspector(s) may or may not allow. I am thinking the same is true in MA.
http://www.contractortalk.com/f50/ma-building-codes-59751/
Good luck!

I cannot confirm the you have a 12 volt nominal PV module from what I have read from your posts here. A PV modules nominal voltage can be derived from the Vmpp or Vmp - Volts at maximum power, (not to be confused with the Voc - Volts open circuit which is a higher rating than Vmp) which is typically found on a label on the back of PV modules. But even if its Voc is 17 volts, chances are it is a 12 volt nominal PV module but the Vmp will be much lower if it is. Possibly something in the 14 volt range. If it is this way it would not perform as well in a hot climate as it would in a cooler climate. It would be great if you could come up with the power curve chart for this particular PV module.

Here is a specification (cut) sheet on a modern day, brand name PV module.
http://sunelec.com/kc130tm.pdf
Take a look under the electrical characteristics heading at "current/voltage characteristics" "at various cell temperatures" and you can see how, as cell temperature goes up voltage goes down. One reason why most new PV moduels have a higher Vmp and Voc than older ones
Let me stress here that I am not saying this what you have. The point is, without specifications of your particular PV module I cannot tell for sure that it is 12 volts nominal. It all depends on weather the 17 volts you mentioned earlier is Voc or Vmp.

MPPT - Multiple Point Power Tracking charge controllers are a good investment especially if the PV source circuit has an exceptionally long wire run, and or the PV array is on a tracker and "sees" the sun from first thing in the morning to last thing in the evening.
PWM - Pulse Width Modulated charge controllers work very well otherwise.

Another good "tool" I use is this. The number of hours of equivalent full rated charge from a PV module per day. Man, somebody needs to come up with a shorter name for that or an acronym or something. This site -
http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/
gives a very good indication of that under various circumstances. Just follow the instructions.

There is another "tool" you have probably heard of, its Ohm's law? You need one other thing to go with the wattages you gave and thats time. How long of time will these wattages be drawing power from the PV/battery/inverter system over a 24 hour period?

I would have to say that best investment I made concerning PV power was a subscription to Homepower magazine.
http://www.homepower.com/home/

Trouble shooting can sometimes be difficult and time consuming even when the trouble shooter is on location. To try and guess the problem over a written forum even more so.
Some inverters have an internal bond and some don't. What does the literature on your 1500 say about it? Could a lightning strike have damaged something else in you home, a load perhaps? Could there be reverse polarity at a receptacle or a dead short?
Its all a lot like being a detective. Sometimes you just have to eliminate all other possibilities, however unlikely, in order to find the culprit. A multimeter is a good tool to have. What you describe sounds like, power from another source finding it way back to the inverter, more than neutral being bonded to ground in more than one place. But there is really no way for me to know this obviously. Could a vdc wire be making contact with a vac wire somewhere? Chess in the dark.

You write that "negative" is bonded to ground in the panel. I associate;
"negative" to the battery vdc, (typically a black wire)
"neutral" to vac and, (typically a white wire)
"ground" to EGC or equipment grounding conductor bonded to a "ground rod" driven into the Earth. (typically bare and or green wire)

Hi James.
Have you tried the OutBack Forum?
http://www.outbackpower.com/forum/

I agree with Jame's point of view Mike.

I would like to add that, photovoltaics are not toys to be trifled with. They can produce a serious amount of electricity that, if not conducted properly, can cause a fire.
The NEC - National Electrical Code is an institution (for lack of a better word) of the NFPA - National Fire Protection Association. http://www.nfpa.org/index.asp

That "bunch of old solar panels" you mention, if "wired" together a certain way, might have the potential to weld steel together. It all depends really on just how many a "bunch" is and what the specifications are. All of the PV modules ratings, not just volts, is the first thing an electrician would look at. He or she would need to know all of those ratings before any calculations could be made for sizing the electrical components for the rest of the system.
Wire size is typically based on the expected amperage to be conducted over them but * it can also be based on such things as voltage drop over the length of the wire, as well as the type of insulating jacket it has and the location where it is intended to used.

There should be a label on the back of your PV modules that shows several "ratings" at a STC. - Standard Test Condition.
Pmax-
Vmpp-
Impp-
Voc-
Isc-
One in particular is the Isc or Impedance short circuited or in a more familiar term, Amperage short circuited. UL - Underwriters Laboratories, requires an additional 125% be added to this Isc rating. The NEC requires an additional 125% to that. So if a PV modules has an Isc rating of 4.75 amps for example, 156% of that amperage must be added back to that amperage and that is where calculations for wire size, based on amperage, starts for a PV source circuit. 125% x 125% = 156%
4.75 x 156% = 7.41 So, based on that example of Isc 4.75, 7.41 amps is used to start calculations for wire size, based on amperage, not just the Isc of 4.75 or the lesser rating Impp. This just scratches the surface! Believe it or not, ambient temperatures can take a part in these calculations. 
Now, perhaps, you can begin to see why electrical contractors require an Electrical Contractors License and why permits must be issued followed up by inspections from the; city, county, or state which ever one holds jurisdiction over the location of a proposed job?

http://photovoltaics.sandia.gov/
In particular,
http://photovoltaics.sandia.gov/docs/John_Wiles_Code_Corner.htm

I can only guess but it would seem to me that this would make getting a "sweet" price on the PV modules even "sweeter."

Uh, so thats a "no" then.

 No's          Yes's
1

Well now thats, something isn't it. (No need to answer that one, its rhetorical.)
So far its looking good for Trace's, I mean Xantrex's C-60 or maybe I should say, The Schneider Groups C-60 charge controller. This is old news but here it is any way.
http://www.reuters.com/article/innovationNews/idUSL854952120080728

Has anyone else every had a problem with the "Over-temperature protection for electronic circuitry" (Installation and Operation Guide, page 1) in a Trace C-60 charge controller?
The events are happening like this. It does fine in the mornings until about 10:00 am and then it starts to open and close the circuit between PV array and battery bank in intervals of approximately 10 seconds closed and 10 seconds open, buzzing while open. This is in normal mode as well as equalize mode. Battery voltage can only hover in the 13's all day long.
Nothing what so ever has changed about the system except for this problem.
I removed the cover plate and set a small 2 inch cabinet fan to blow across the heat sink and just inside the unit below the heat sink. This cured the problem. This tells me there might be something wrong with the temperature sensors but I don't know.

Anybody else have this problem with a Trace C-60 charge controller?

[quote author=Thomas Allen Schmidt
 If the array is tilted south at latitude and we multiply that by the equivalent number of hours of full rated power per day, averaged out over a year, expected in Florida...
[/quote]

I said that wrong. It should be - The number of hours of equivalent full rated charge.

As you may allready know, a PV module does not make full rated power the whole day. Its proportional. So the amount of power it does produce in a day is added up and divided by its full rated output. Hence the phrase - the number of hours of equivalent full rated charge (or power.)


http://photovoltaics.sandia.gov/
http://www.nfpa.org
One item that I cannot put enough importance on, that is a must have on a systems such as these is lightning strike protection. Charge controller(s), inverter(s), battery monitor(s) all utilized electronics and even nearby lightning strikes can cause damage to these items.
http://www.deltala.com/
 
Also, PV arrays mounted on dwellings must have GFP Ground Fault Protection on the PV source circuit(s).
http://www.iaei.org/magazine/?p=790

One other thing, have you given any thought to fire suppression? Obviously being on an island there would be enough water but if a house fire were to happen, God forbid, would you have the means to move a large enough volume of water to fight it?
http://www.jmefireequipment.com/

Muchas gracias Senor Friedman.
Indeed, $30,600.00 it is!
I am glad it was just that and not something less obvious.
I hope that $30,000.00 mistake didn't scare you away Mr. Foster.
While I am here i might as well figure up the battery bank. Again I'll pick a name brand battery out of the proverbial hat. Surrette's S-530 Rolls - 6 volt - 400 amp hours. It would take 8 of these wired in series to make one 48 volt nominal battery at 400 amp hours. If we go back to that figure of 36.4 kWhs of solar power from before and divide that by 48 volts nominal that would be 759.25 amp hours.

This is where you really need to know what your expected power needs are going to be first but I'll put that aside for now.

I like to multiply the battery capacity by a factor of at least 5. This helps to keep the battery state of charge in the top 20% of full charge, it can give you several days of power without sunshine, and it helps to prolong the over all life of the battery. So, using how much power would be produced by that PV array and assuming that is what will be used in a 24 hour period, 759.25 times 5 equals 3796.25 amp hours or if we divide that by 400 that would be 80 of those s 530's at $350.00 each or $28,000.00 by the way shipping is free east of the Mississippi on orders over 1,000 pounds which subsequently 80 of them would weigh 10,400 pounds.

I hope you can begin to see why its better to calculate the anticipated power needs first and how that could affect the overall cost of a system. It makes that second microwave oven a little less important if you catch my drift. How difficult is it to obtain propane gas at this island?
Hot water could be solar but then there is cooking and refrigeration to consider. Refrigeration can be electric as well, there are a lot of "off grid" refrigerator/freezers to choose from. I bit the bullet and went ahead and got an EZ Freeze 19 cubic foot R/F. Ours using no more LP than a Servel 8 cubic R/F despite what the advertisements say. Of course I enclosed it in a way that the back of it is isolated from the interior of the house and cut a hole in the floor, put screen over the hole, made a hole in the ceiling and a chase from there to the bottom of the roof, and then one of those turbine roof ventilators over top of the chase. If I don't block the hole in the floor in the winter time it works too good.

If I could make a suggestion? Start small with your PV array maybe 2,000 watt (it can be added onto later) but large with the battery bank and pure sine wave inverter(s) assuming you want 120 or 120/240 vac, if so, wire your house for vac like any other conventional house but don't use any multiwire branch circuits (sharing of neutrals) inverter manufactures warn against this, consider all of your appliances carefully, an 8 cubic foot R/F cost less but years from now you might wish you had gotten the bigger one. Living on an island I imagine a trip to the grocery store isn't a short one.

Man! I could go on and on with this but I'll let you absorb this and wait for a reply.

http://www.solarbuzz.com/companylistings/unitedstates.htm

So roughly you'll have a roof area on the south side pitch of 15' x 40' depending on the amount of pitch obviously for a total of 600 sq. ft..
I'll just pick a brand name PV module out of the hat,
Kyocera KC130TM, it measures 25.7 x 56.1 inches.
thats 8 modules long ways east to west and 7 modules eave to ridge for a total of 56 modules or 14 sets of 4 wired in series for 48 volts nominal for a total of 7,289 watt PV array. If the array is tilted south at latitude and we multiply that by the equivalent number of hours of full rated power per day, averaged out over a year, expected in Florida...
5 times 7,260 equals 36,400 or 36.4 kWhs or kiloWatthours.
http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/serve.cgi

Is that enough?

Think about it this way, if someone is paying the power utilities $100 per month and they are paying $0.10 per kWh that means they are using about 1,000 kWhs per month or divided by 30 that would be 33.3 kWhs per day.

The 56 KC130TM's could cost as much as $10,200.00 per pallet of 20. 3 pallets of 20 of course would be $60,600.00 might as well get the other 4 right?

Keep in mind now, that this is the most you could put of, this particular PV module, on one side of that roof.

The best practice is to figure up what your expected power usage will be in a 24 hour day first and go from there. Be liberal. Try to think of everything. You may what to round everything up and plan for expansion in the future.

I lived off grid for more than 20 years (no electricity at all) before utilizing a 1,000 watt PV array 10 years ago. Its plenty for the 4, sometimes 5, of us but then we were not pre-conditioned into believing the lie that the human race needs electricity in order to survive on the planet Earth. Benjamin Franklin didn't utilize electricity, he lived to be what, 80 something and look at what he accomplished in his life time. Not that I am comparing myself to him, mind you. I am just an electrician. He is the only American to have his signature on the three major documents pertaining to America becoming a nation in its own right.� 

Lets us hear back from you.

I second that cheer.
I for one have a sincere respect for the Alt-E Store in as much as they are willing to maintain a community forum and not just another "love only me, and praise only me, mention any other and despair bulletin board."
http://www.theage.com.au/articles/2004/10/11/1097406478358.html?from=storyrhs
Think about, who would Rocky be without Apollo Creed.
The eye of the tiger Bobby.
I too have placed links to other stores, but not as an attack on Alt-E. Renewable energy is very expensive to implement. The fact that the U.S. government as well as state governments offer incentives (government assistance)  to purchase them and the RE industry promotes this, is testimony to that fact. If those incentives were not there I doubt RE would be selling as well as it is today.

As for the UL standards, "the winds of change they are a blowin."
http://www.innovosolar.com/img/TEM165-180M-B.pdf
I didn't see the UL "stamp" ether but...

http://www.iec.ch/online_news/etech/arch_2005/etech_0405/news.htm

http://www.ul-asia.com/news_nl/2007-Issue24/page8.htm

I can tell you what I do to clean the glass on my PV modules when they get dusty or covered with pollen or bird poop and a simple rinse with clean water doesn't do the trick. A little bit of mild dish detergent, a soft rag, lots of clean water and, some elbow grease. As for the back of the PV modules, mine stay relatively clean except for spider webs, congregations of granddaddy long legs, a few stink bugs and, the occasional wasp nursery. I just let them be. They aren't doing any harm. I am surprised that dirt daubers haven't built nursery's there. I guess its too hot?
I wonder if anybody has a problem with green lichen growing on the north (under) side of their PV modules? Too hot maybe?

Interesting. Nice find. I took a look at the Zunibal web site... Very secretive, they sure don't want to share too much information about their products. I only saw two items that have what appears to resemble, but not exactly, your PV module; the "FOR-TUNA" and, the "TUNABAL 15."
 It would appear though that these two devices are equipped with battery and therefore a charge controller of some sort. I guess all of that didn't come with? The battery can't be but so big. Sealed drycell maybe, light weight (has to float.) I would guess the charge controller is a simple one, all electronic obviously. Maybe a simple shunt or load diversion type.
Best of luck to you building your system Tod.

http://www.satamatics.com/pub/news/action=article/cpr=cpr0005/vcpr=1/Zunibal_Signs_up_for_Satamatics_Global_Coverage.htm

http://weblog.greenpeace.org/pacific/archives/001698.html

Wow! No information at all about it? Name or serial number? What are its dimesions and how many cells does it have? What color and shape are the cells? Does it have an aluminium frame (painted or unpainted) and J-box with screw terminals inside?

While trying not to get into semantics, when I hear that an electrical device "draws," I think "a load draws an amperage of..." Were you write that it "draws 18-19v without a load." thats called open circuit voltage. If you take a look at the rating of new PV modules listed in Alt-E Store, you might see that certain 12 volt nominal, PV modules have similar open circuit voltages to yours. (Most likely not because of the age difference.) As well there is rated amperage and short circuit amperage listed as well as wattage. These are all measured� using a STC or Standard Test Contition. There is also "peak" voltage or what I call the "working voltage" of a PV module. This is listed as well. So there is; Open circuit voltage, peak or "working" voltage, and nominal voltage. The last one, nominal voltage is not "listed" but it may be advertised.
What you have sounds like a 12 volt nominal PV module with a working voltage of maybe a little better than 14 volts. Not a good panel for hot regions like the equator. For the sake of simplicity I won't go into PTC ratings chances are your PV module was made before all of that came along (see below.)

Again with the semantics. When I hear regulator, I think of the voltage regulator on a 57 Ford pick-up truck or something. Sorry. Look up charge controllers in the Alt-E Store.

Chances are that it may only make about 2 or 3 amps, There are certain handheld electric meters that can measure dc amperages in series.� 

http://www.sunlightelectric.com/pvmodules.php

Here is an idea to "kick around" since we are on the subject of cooling homes via alternative means.
http://www.propanecouncil.org/uploadedFiles/Fact_Sheet_11957_Gas_Cooling_3-07_v5.pdf
In particular, in the above file on the bottom of page 2
"market opportunities," "absorption AC" and, "off grid homes."

Assuming that your fridge is vac powered from an inverter - is there any mention or warning in the inverters literature about using capacitor start motors?

http://photovoltaics.sandia.gov/docs/PDF/Brief2.pdf

Just a thought.

We tried using a conventional clothes washer on a DR1512 and it did fine as long as it was a Sunny day and we gave the PV time to bring the voltage of the batteries up higher than nominal. The worst time was at the beginning of the spin cycle. There were times when a cloud would move in and get between the Sun and PV array, just at the start of the spin cycle and, we weren't looking and this would cause an overload on the DR1512.
 Watching the dc amperage on our Bogart 2020 monitor while the washingmachine was going through a complete wash cycle, (about as much fun as watching paint dry) it would get to the spin cycle and stop for a moment, the battery voltage and the charge amps would go back up then the spin cycle would kick in and I watched the charging amps go from +45 down to -70. Of course the voltage went down just as dramatically. Once it was up and spinning at speed though, the 2020 would show amperage getting right to the point of a + charge and thats where it stayed until finished spinning. We stopped using that washingmachine cause we didn't want it to smoke the 1512. Cheaper to replace a washingmachine than a DR1512. Can you believe that?

http://www.thenaturalhome.com/
Now if you really want to reduce gasoline consumption just reduce horsepower.
http://www.buggy.com/

Can you determine how much water is needed? How many gallons per 24 hours?
Is changing the water pump out of the question?
It would take a considerable investment at first but this pump lends itself to upgrades as time and money allow.
http://www.solar4power.com/solar-power-water-pump.html
Of course an elevated storage tank helps in these types of situations. They say this pump delivers 3 gallons per minute by hand from a hundred foot well. 20 minutes of pumping by hand should deliver in the vicinity of 60 gallons. 20 minutes 4 times a day = 240 gallons. Plus who ever is lucky enough to get to pump the water gets a nice little work out.
If pressure is an issue in the home a small low voltage dc pump can be added. Batteries and solar if its needed.
Just throwing out a few ideas. Without specifics such a gallons per day, any required pressure, I can't narrow it down any more than that.
Each foot of tank tower height adds 0.43 pounds per square inch of pressure. Keeping pipes as large as possible right up to the point of use helps with volume at low pressures.

When I started out, I was utilizing a pitcher pump on an 11 foot tower with several plastic 55 gallon corn syrup drums. (recycled from a nearby candy factory) This did allright fro a short while but as our family grew so did the pumping time. (it helps if your ambidextrous)
Now I utilize a 1,000 gallon tank on a 30 foot tower with 3 inch down pipe, reduced to 2 inch underground up to a "manifold" with several cutoffs where its all reduced to 3/4 inch just before going to various uses in our home being reduced at the last possible point to sinks, commodes, and showers. Same on the hot water supply.
 I had installed a new shower conversion valve once and it had a water saver feature. the water just dribbled out. Once I removed the plastic reducing disc though I couldn't tell the difference at the shower head from any other shower with a conventional water delivery system. Water is pumped up to the tank tower via Pacer pump with a Briggs&Stratton. Takes less than half a cup of petro to move about 800 gallons in less than 5 minutes.
http://www.pacerpumps.com/econoAg.php
I think if I had it to do all over again I would have went higher with the tower and used bigger main pipes but "beggars can't be choosers." A lot but not all of what was used for the construction of the whole system was reclaimed stuff.
http://www.tank-depot.com/browse.aspx?id=2
The tower is constructed similar to the old railroad water towers with four poles and lots of cross bracing.
http://marxtinplatetrains.com/img/water-tower.jpg
This is the closest tower I could find that resembles what I built.

You might already know about this one but here it is just in case you don't.
http://www.motherearthnews.com/
Check out the archives. This magazine has been in print since the late 60's! Its "haydays" were all during the 70's though with the, then popular, back to the land movement.
If you're ever near Hendersonville, North Carolina stop by the Eco Village.

For thousands of years the human race did not need all of these energies to live on the planet Earth. It has only been in the last 150 years that this has occurred. What happen to the human race? Its been said that good mental health is relative time and place. For example In his own time and place Hitler was perfectly sane even though the rest of the world believed him to be insane. We believe George W. Bush to be perfectly sane but I doubt thats true of Osama bin Laden and the members of al-Qaeda. I wonder what Hitler would think of George W. Bush? Take these men at out of their time and places, change them around and you can imagine what would happen to each.

Pity about Earth.

Where you say "oil burner" I assume that is a fuel oil burning water heater and if it is like most all other water heaters it is controlled by a temperature switch. If so then all it "knows" is if the water is at a preset low temperature it "calls" for heat and when it reaches a preset high temperature it turns the heat source off. If the water coming in from a solar water heater is in between those preset temperatures it will not "call" for more heat and if it does, the amount time the heat is on, is shorter as determined by the incoming water temperature. Although some solar water heaters can reach extremes of their own if not regulated. I have seen simple flat plate solar water heaters reach temperatures of 180 degrees Fahrenheit, where as most domestic water heaters are set to a high limit of 120 degrees Fahrenheit with safety temperature/pressure vales that "blow" at 150 degrees Fahrenheit or, I think its, 200 pounds per square inch which ever comes first. 
http://store.altestore.com/Solar-Water-Heaters/c402/
If this doesn't do it for you there is also -
http://www.kingsolar.com/
and - http://www.radiantcompany.com/ - and - http://www.warmair.com/html/hydro-air.htm - or - well, I think you get the idea.