Thomas Allen Schmidt's posts

Your right. I am sorry. God! I can be such an idiot. I keep forgeting how easy it is to get off of the subject of RE here at Alt-E general discussion board.
I must be crazy to suggest that anybody would just quit energy (renewable or otherwise) cold turkey. Thats like saying "quit living!" To actually go to the main breaker in our home and reach up and turn it off. Its as if I were asking them all to commit suicide in mass. Man! What was I thinking?

Okay, I think I am trough beating myself up now. Back to the subject you brought up, "How fast is your solar investment returns?" Can I change that to past tense? Because I lived with out any electricity, at all, for nearly three decades before utilizing photovoltaics. I figure that at the going rate of $0.15 per kWh, based on my current electricity usage, summed up over a period of 30 years I would have saved somewhere in the neighborhood of about $2000. Considering how much the PV array alone cost me, I still have about three more decades to pay for it.
But. Hey! You know what? If I base in on someone else's electricity bill that pays around $100. a month then,,, Wow! I could buy a brand new car with what I saved. Does this fall under the axiom "the more you spend the more you save" and, all that? I am confused. Does this mean I could be driving around in a brand new car instead of an old "beater" pickup, if I had just used more electricity? Man, this all so complex. Its a good thing there are so many "brianiacs" in the field of renewable energies to figure it all out for us and tell us how smart we are to use Renewable energies.

---------------------------------------------------------------
I geuss this is what happens to someone that lives without electricity for nearly 30 years.

Wow, I am surprised that, this one, did not get a rave of replies. This board has really died off lately. I guess with RE gaining in public awareness and the RE industry as a collective reporting earnings in the billions, no one feels the need anymore to stick their neck out and defend RE.

I am curious Gergely Markolt, is your calculator based on the kilowatthour rate as posted by your electricity provider? Does it take into account the cost of such things as Operation Desert Storm? I know Bush said "its not about oil" but does anyone really believe that? Even Forbes magazine reported that, one of the things Saddam Hussein was attempting to accomplish was to change the price of crude oil from being based on the U.S. dollar to being based on the Euro dollar which means we here in America would be paying in excess of $10. a gallon for gasoline by now. What is the price of a human life? $100,000.? -$100,000,000.? - Would it be the same for each and every one of us? Or would certain ones of us believe that we are worth more than the other? Is a General worth more than a Private? Payscale would suggest it. More privates die than Generals but that could be simply because there are more Privates in actual combat than Generals. Is the life of a U.S. President worth more than that of young child. You would think not because we always here "women and children first." But what about the children who lost their fathers to Operation Desert Storm. I didnt see George Bush with a gun in his hands on the front lines.
(More about war. http://asis.com/users/stag/thewar.html )

Its been said that our monthly electric bill is misleading, that we are paying out of more than one pocket without even knowing it. I believe this to be true of every monoply, even RE as a collective. The most effective form of control in any area of life is monopoly. When you control every single facet of something, be it gold or oil or shipping or the media or corn or water or air or flu shots, you control the people.

That last, flu shots, think about how natural selection over thousands of years has caused most humans to be resitant to flu viruses. A lot of people paid the price of their lives in order for the rest of us to be able to live through a flu infestation. WE, humans, got stronger while flu viruses got weaker. Now think about what  is happening now with the flu shots we can get. Because productivity in the work place was suffering everytime the flu showed itself something had to be done.
Because of this, I fear that what is happening is a reversal. We, humans, will be getting less and less resistant to flu while the flu gets stronger.
Now, imagine  a time in the not to distant future when we all, every last one of us has to take that shot every year without fail or we will die. Big bucks for the pharmaceuticals right. Look at energy in this same way. We, humans have become so dependent on energy that if it were to disappear over night a lot of us (billions) would die before the first year was over.

A message to all of you that want to save the planet Earth and save money on energy, "Just Say No To Energy".
Think about it at least. How the human race as a whole lived, without all of these energies we take for granted today, for thousands of years and how now in just the last 100 to 200 hundred years we believe we cannot live without them.

Pity about Earth.

Its 6:15 pm. Do you know where your batteries electrolyte is at?
http://www.engineersedge.com/battery/specific_gravity_battery.htm

Two weekends a month or, 4 days out of 30?
If only half of those days are sunny enough that would leave 13 days total. So if we take *the amount of power to be used for two days at the retreat and divide it by 6.5, that would approximate the amount of power that would need to go into the batteries while the retreat is not occupied so that hopfully the batteries would be recharged to 100% when someone arrived on the preceding hiatus.

*This factor needs to be known, as close as possible to realworld conditions, in kiloWatthours or, kWh's.
One other factor would be helpful to know in advance and that is the number of hours of equivalent full rated charge at the prospective PV location.

I once saw an article, in a Mother Earth News magazine, where this person made a "homemade solar time clock" from collected bits and pieces of electronic gadgetry and placed it in the PV array's prospective location. Of course he had to record the location of the hands of the analog clock each day but I am sure there are accumulative digital clocks the would do just as well. I am supprised no one has put such a (inexpensive) device on the market by now. For site analysis.
I think a Bogart Tri-Metric monitor might do the trick and it can become a perminate part of the system later. Just have to come up the right size, very small, very inexpensive PV module. Or, just go for broke and put a 100 watt PV module up there and see what happens. As long as the charge controller is sized for such a possible future, you can always add more PV! Right?

As Mr. Cormican stated, "the possibilities are endless."

I suppose time will tell and how dependent one might be on the electronic technologies of this day and age.

http://science.nasa.gov/science-news/science-at-nasa/2010/04jun_swef/

Pssh! Look who I am talking to.
Hmm. I wonder if any thing will happen to my charge controller?

Are you a renewable energies worker?
Do you feel like your not getting payed a fair amount?
Are you an employer of RE workers and, you feel like your paying them too much allready?
Maybe you just a trial lawyer and business has been slow.
____________________________________________________________

First they came for our health care ...

Now big government is coming for our paychecks.

That's right, some in Congress are pushing a bill called the "Paycheck Fairness Act" -- and it's little more than a handout to the trial lawyer industry.

Under this wrongheaded bill, employers would no longer be able to pay employees differently based on market forces, negotiating ability or even the amount of revenue they generate in return for the employer.

Employers would be open to a flood of frivolous "discrimination" lawsuits -- a windfall for trial lawyers, at the expense of jobs.

This bill isn't about fairness. It's about tipping the scales in favor of plaintiffs' attorneys.

Need more evidence that this bill is a dud?

It would make it easier to file large class action lawsuits and provide unlimited "punitive and compensatory" damages. In other words, trial lawyers strike it rich.

Supporters say it will remedy the so-called "pay gap." But it ignores common-sense, legitimate reasons why an employer may pay different employees different salaries.

It lets the federal government second guess routine decisions made at a private business. How can that be good for our economy?

Empowering big government at the expense of American employers is just plain bad for our economy.

Sincerely, Bill Miller
Senior Vice President and National Political Director
U.S. Chamber of Commerce

Have you tried holding her down and scraping a knife and fork on a plate until she submits? No? Well, probably just as well. That stuff might work in the movies, but in real life somebody goes to jail.
How about this idea?
http://greensource.construction.com/news/2010/100302Photovoltaic.asp
Obviously, there are details that would need to be worked out, but you seem like a reasonably intelligent person.

If I could, suggest another alternative?
A linear current booster as opposed to battery/charge controller setup.
Such as, but not limited to - http://www.altestore.com/store/Solar-Water-Pumps/Linear-Current-Boosters-For-Pumps/Solar-Converters-Ppt-1224-3A-1224V-Lin-Curr-Booster/p1356/
There may or may not be the need for additional PV. As Mr. Hall pointed out, actual motor load, run time and, if I might add, *insolation are key factors. But experimenting can be fun too. As long as its done safely, (of course.)

http://www.infinitepower.org/

* http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/ Once you are at this site, try;
1 - average
2 - annual
3 - flat plate tilted south at latitude
4 - then find your location on the map. This will provide, under the very best of circumstances, a general idea of the number of hours that a pump might run during a good sunny day.

Another piece of useful information?
http://www.geo-orbit.org/sizepgs/magmapsp.html

Here is some information I found to be useful, Jimmie O as a "tool" to make comparison with.
http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/
Another good "tool" I have found to be useful is my Bogart TriMetric 2020 monitor.
http://www.bogartengineering.com/
Other good tools are, angle finder, 12"x2"x4" cut square on on least one end, a good flat board roughly 3'x3/4"x6" and, a magnetic compass, which of course you'll want to know the degree of declination from solar south. It helps as well to secure the angle finder to one end of the broadside of the flat board.
http://www.ngdc.noaa.gov/geomagmodels/struts/declZipE
Being knowledgable of our Sun helps as well. Knowing which days are the shortest (winter solstice) and the longest (summer solstice) and which days have an equal number of hours with the night (vernal and autumnal equinox.)
http://antwrp.gsfc.nasa.gov/apod/ap061223.html

Just for fun;
The analemma of Mars.
http://antwrp.gsfc.nasa.gov/apod/ap061230.html
Saturns north pole.
http://antwrp.gsfc.nasa.gov/apod/ap081119.html
Have any of you every thought about what its like to be on a boat, on the open water, looking out ahead of you in the direction of travel, seeing nothing but open waters? Its tempting to let the boat go on its own feeling safe that it will not hit anything like a log floating just below the surface or, as unbelievable as it sounds, an iceberg.
Our entire solar system is like that boat and there is nobody at the helm, there is no helm. We are traveling through space without a clue as to what is out in front of us. People on Earth thousands of years ago new of this simple fact and they set to watching the stars trying to gain knowledge of what was to come.
We still do this today only, most likely, we will pick up a newspaper and turn to, our horoscope.
http://www.crystallotus.com/TheTransition/007.htm

Wow! 92 to 96% efficiency. Thats higher than I would have guessed from a *Joule thief. Stepping up 12 vdc nominal PV to charge 48 vdc battery. I am curious, would the PV power from the 12 vdc charge controller go right to the converter or would it be necessary to connect the PV modules right to the converter? If the later, what would control the charge?
 
I'd be interested to know what the efficiency is of a Toyota Prius NHW-20 with its 500 volt motor and 202 volt battery pack?

* http://www.corrosion-doctors.org/Biographies/JouleBio.htm

It just occurred to me that, in all that I have seen about these Condumex charge controllers, I haven't seen the UL listed "stamp" of approval.
I might be asking a dumb question George Anna, but is that Condumex CMCX 12-15-20 UL Listed? UR Listed? Or any of these to follow in this weblink?
http://www.safetylink.com/

 "Didn't know about the metal melting issue, so that was good to know, and I'm not sure about what is meant about the continuity problem."

In this case, continuity, is just a word used to describe the flow of electricity. A free flowing continuity is good. Continuity that is not free flowing can cause heat. Think of it in terms of a creek flowing unobstructed and a creek that beavers have damed up. The beaver dam creates resistance to the flow of water and floods. In an electrical circuit resistance to continuity creates heat.

I see from David Ames recent post that a complete spec. sheet and manual of the Condumex CMCX 12-15-20 is still not attainable but I do see the specs. as advertised and think I understand most of them.

-Nominal voltage - 12 vdc
-Maximum amperage from PV modules -  15 amps.
-(This one I am not sure about) - 20 amps.
-Maximum open circuit voltage - 22 vdc
-For use with lead acid batteries.
-Disconnects PV from batteries at 14.8 vdc
-Reconnects PV to batteries at 12.9 vdc
-Disconnects load from batteries at 11.8 vdc
-Reconnects load at 13.2 vdc
-(Not sure)
-Something about a blade type 3 amp fuse.
-Lightning protection.
-(Not sure about this one) - 10 to 15 vdc
-Efficiency factor - 5%

From what I can tell as compared to the PV module specs. for the EC-102-G, all of that looks OK. There is still the question of that 20 map rating. A 15 amp charge controller with a 20 amp??? Load control???
(This is where that "mad scientist" in me might have tried both PV modules on one charge controller just to see what happned. Supervised of course.) 

"I used to have a problem with getting the caps to turn so that the fuse "connects" and now it seems I don't even need a cap (on some of the fuses)-- I can get them in and out ok, but they're not loose anymore. Is this good, bad or indifferent?  If/when they get loose their respective light goes off... I check that as well as fiddle with them and they stay tight."

I suspect from this statement that, damage to the fuse holder from excessive heat has happend already.
Is there any way to un-install this fuse holder and re-install a different type of fuse holder?

I wish I could actually see, feel and, smell it during operation, that would tell me conclusively what the problem is but not so much what caused the problem to start with so that it doesn't happen again.

SERIES 4000. 6 - VOLT. 3 - CELL
Model Rolls S-530
Cap 100 Hour 1.75 VPC 530
Cap 20 Hour 1.75 VPC 400
Length (in) 12 1/4
Width (in) 7 1/8
Height (in) 16 3/4
Weight (lb) 130lb
Warranty 7 year


400 amphours at the 20 hour rate.

www.homepower.com

My first piece of advice, Sebastian, would be to take your time and read up on PV battery charging systems first. There is tons of information out there on the web and in book stores. Where you might read what I have to say and not understand it fully, some one else could explain it to you in a way that "clicks" with you. So, don't rush in to it.
Pictures, wiring schematics and, charts help a lot!


On the back of each of your 3 PV modules, Sebastian, there should be a label stating the output of the module at standard test conditions or STC.
What is the value given for Vmp or maximum power Voltage?
This will discern the nominal voltage of your battery charging system and the type of charge controller you will need to utilize.

For example: If the Vmp on your PV modules is 17.4, then it is consider to have 12 volt nominal charging abilities. Although each PV module can be wired in series with an additional 1, 2 or, 3 more identical PV modules to obtain a higher nominal voltage system of 24 volts, 36 volts or, 48 volts nominal and most charge controllers will work here, !!!provided that all of the other criteria are met!!!
 
On the other hand if the Vmp is high like, 67, then you will need to wire them in parallel and utilize an MPPT charge controller that can reduce the voltage to a nominal battery voltage as described above ie; 12, 24, 36, or, 48. !!!Again, calculate the other criteria!!!

Because you stated, "So I need to buy one battery and charge regulator for installation." I am guessing that you want a 12 volt nominal system?

To size the wire, fuses and, charge controller you will need to look on that STC label again for the value beside Isc or short circuit amperage and add 156% to it.
For example: If it happens to be 4.56 then simply multiply 4.56 X 1.56 = 7.1136 or, rounded off to 7 amps.   
If there is more than one PV module wired in parallel then you will need to multiply that by the number of PV modules.
!!!Also look on that STC label for the maximum fuse rating or maximum series fuse rating!!!
 
A good place to start. - www.homepower.com - Once your there, click on, "THE BASICS" and it will lead you to more detailed information.

When I first ventured into PV battery charging I was given a year subscription to this magazine by a colleague. I kept up the subscription for many years and I feel like it was my best investment, by far!
Thousands of dollars, PV modules, batteries, charge controllers, inveters and all have come and gone but the knowledge of how to utilize them correctly and safely has been priceless.
I don't know invented the phrase but it applies here -
"Knowledge is POWER!"

Well, there is a phrase that is used Shaman Abla, maybe you have heard it? It goes "All things being equal..."

?

If I were to assume that you have found these particular PV modules to be of equal abilities then, all things being equal, I would use the single 200 PV module.
Why?
Simple, less wiring to do and the mounting would be less complex.

Without particulars on the PV modules and the intended region ie; equatorial, polar, or a median, I can't help you any more than that.

BATTERY THEORY 
*The purpose of a battery is to store chemical energy and to convert this chemical energy into electrical energy when the need arises.

*A voltaic cell develops a potential difference when electrodes of two different metals are immersed in an electrolyte.   One electrode accumulates a positive charge.   The potential difference is due to the difference in charge between the two electrodes.

*The chemical equation for a lead-acid battery during discharge is: . PbO2 Pb 2H2SO4 discharge ® 2PbSO4 2H2O

*The chemical equation for a lead-acid battery during charge is: PbO2 Pb 2H2SO4 charge ¬   2PbSO4 2H2O

*When a lead-acid battery is discharged, electrolyte and the active material on the plates of the battery are consumed to produce water and lead sulphate.

*When a lead-acid battery is charged, electrical energy is added to the battery, causing the water and lead sulphate to be consumed and produce electrolyte and active material.

*Since specific gravity of a lead-acid battery decreases proportionally during discharge, the value of specific gravity at any given time is an approximate indication of the battery’s state of charge.

The last one pretty much says it all, "an approximate indication." So, for me, if all I can get is an approximation anyway, I would just as soon not mess with the acid electolyte and go with the state of charge battery monitor. Of coarse, all of the other "bells and whistles" included on the Bogart TM2020 are a bit of a luxury but for no more than what I paid for it, they are worth it to me.

Uhm, I don't know if this will help you, or not but!
I used to fret over my batteries. I never understood them really, until I was thumbing through a high school chemistry text book and came across the explanation of a flooded cell lead acid battery that stated; these batteries do not store electricity, they convert electrical energy into a chemical energy and store that until such time as electrical energy is needed and then its converted back into electricity. It even gave the chemical equation. 

I don't even use a hydrometer on my own battery bank anymore. I calculated my electric power needs for a 24 hour day/night period and sized the battery bank just a little more than 5 time larger. Then I sized the PV array to replace, what is typically used in that 24 hour period, in just one sunny day.
Oh, I also have a Bogart TM2020 battery monitor mounted in the wall right by the front door just above the light switches. http://www.bogartengineering.com/ It reminds me to equalize each month. Equalizing is as simple as pushing a button on the Trace C60 charge controller. When its done it resets itself.

Of course there is still the chore of topping of the battery bank with distilled water before the equalizing charge but that gives me time to inspect them for any possible problems and it all takes me about 20 minutes, once a month.

It all worked on a set of Trojan T-105's I had. I got a little better than 7 years of service out of them before they started showing signs of age. Hoping to get 20 to 25 years or better from the lastest set of Surette 530's.

One of if not the greatest means of increased longevity of a deep cycle battery bank is, shallow cycling.

I do not know of such a "step up" charge controller on the market but, I suppose almost anything is possible these days.
You do know that any "transformation" comes with a "price," right? As the old saying goes, "There no such things a free lunch." Its like a toll that the universe demands from us to utilize energies within this physical realm.

Will less that 160 watts provide a worthwhile amount of charge to a golf cart in just a few hours a day? Even with 5 hours of equivalent full rated charge from your PV modules, this would only amount to less than 0.8 kWhr's. How long would that 0.8 kWh's last on your golf car?

Even conventional golf cart chargers that transform 120 vac into 48 vdc exacts a price that manifests itself in the form of heat. The few I looked at, charge at a maximum of around +/- 20 amps. In just 1 hour of charging thats is less than 0.96 kWh's. How long would that 0.96 kWh's last on your golf cart? If it had 5 hours to charge?

Yeah, it still amazes me just how devious the human race (we) can be.
http://www.criticalthinking.com/company/articles/deductive-reasoning-skills.jsp

So many variables to be exploited.
http://www.turbulence.org/spotlight/thinking/chess.html

Not to mention, ones own perception within the time space continuum in relationship with or as compared to, anothers perception.
http://antwrp.gsfc.nasa.gov/apod/ap100321.html

"When learning becomes a simple, repetitive pattern of memorization and multiple-choice test-taking, students' brains do not get many chances to grow and evolve. Students become like filing cabinets for facts and figures, rather than engaged participants in their own educations. Teaching deductive reasoning and exercising it regularly helps students see the patterns and underlying assumptions that govern all human knowledge."

There was a time Tracy when Alt-E didn't seem to mind web links to competetors posted in their forum and, I greatly admired and respected them for that, but I think that has change over time. Understandably, I mean what with the economy here in America and around the world going to the dogs. Its dog eat dog. I wish I could tell you all here, where to go to get a package deal of;
52   GSA-60 KANEKA 60 WATT MODULE   
1   MNPV16 COMBINER BOX   
13   8AMP 600VDC KLKD FUSE AND HOLDER   
1   DELTA DC LIGHTNING ARRESTOR LA602DC   
1   SB3000US SUNNY BOY 3000W INVERTER     
1   DU221RB SQUARE D AC DISCONNECT 30 AMP     
1   DELTA AC LIGHTNING ARRESTOR LA302R   
13   MC 3 Cables 30 ft
for just under $6,500. but I suppose that would disrespectable to Alt-E. I mean they are gracious enough to have this forum.

Have I every told about my paternal grand parents that used to live in Miami, Florida many years ago? Have you every been there? Its been a long time ago since I was there. It was the late 60's when we, my mom and dad and brothers and sister and I, would all load up in a station wagon and drive all night to visit them. If my memory serves me correctly it wasn't too far from 511 NE. 15 street. I remember they had a huge mango tree in their back yard. But then again in Miami who doesn't? Their both gone now, God rest their soul. I miss my Poppy and Nanny.
Oh, look at me blabbering on! I have to get ready for Easter Sunday dinner with the in-laws... So long.

It is rather interesting that if, a company such as Solectria is as reputable as they would have us believe that they are, that they would list a minimum dc wattage input if, indeed the 3000 had a minimum dc wattage input.
I mean they do list a maximum dc amperage input along with the minimum strike voltage, now don't they?

Reminds me of the time I went to a fast food burger place and saw the picture of a hamburger on the menu and boy did it look so good with the lettuce and tomato and a big ol' slab of char-broiled beef and all. I was drooling I was trying to place my order. Well, I get to table, drool hanging off my chin, open up the wrapper and there lied a thing that look like a rhinoceros had sat on it, butt crack and all. Not at all like the picture I assure you. I just couldn't pull myself to eat it. What a disappointment. Just goes to show you, you can't always trust what you see on the menu thats for sure and I'll never eat at that place again.

But about your problem. You have all the stuff to install it an get it up and running right? I'd say hook it up and give it a go. Whats the worst that could happen? It just won't come on at all or it won't make much power right?
I'd read that installation and operation manual real carefully though and make sure I wasn't going to void any warranties, expressed or implied.

_________________________________________________________

" i don't see any way of damaging the unit with low input as that would be a normal occurrence with snow/weather/low light conditions. i understand your concerns in regards to the warranty and excuses for voiding it. could be a chance that alte may have your back covered with post #4? i would like to see that company return some answers to repeated query's none the less!"

Now why didn't I think of that?

All kidding aside.

Diagnosing or troubleshooting a problem like this is a lot like being a police detective solving a murder and arresting the guilty. He has the physical evidence, a list of suspects and so on, from there its a "process of elimination."
If this was a service call that I was making, not knowing anything about the system or any thing about the cc, just relying on experience, some of the very first things I would check would be;

Verify the correct type of fuse and its ratings, according to Condumex, is being used.

That each pair of positive and negative wires (pv to cc, cc to batt.) are the same length and same type of wire. Also that it is the correct size and type of wire.

Verify polarity throughout the system.

All terminations are clean and tight.

Verify the ratings of the cc as compared to the pv. In particular the Isc. (Spec. sheets for both would be nice here.) Don't forget the 156%. (The Evergreen EC-102-GL has an Isc of 7.28 amps times the 156% means there is a potential of 11.36 amps according to UL and the NEC and this is where calculations for sizing electrical must start.)
http://homepower.com/view/?file=HP79_pg110_CodeCorner
Does a load come on during those times that the fuse "burns up" such as a thermostat controlled fan or something? (Oh! Don't assume that because I elaborated on this one that I think this the problem.)

I had a similar problem with a Trace C-30A+ cc of my own way back when they first came out. A simple on/off cc. It controlled, but the fuse got hot. I never did figure out why. The best I could come up with was that there was a problem on the pc board. What every it was, the damage had been done. I have to admit though, in those days I was a bit of a mad scientist, experimenting with loads, pushing the limits and all. I just don't know which experiment it was that corrupted it. I might have even reversed polarity by mistake at one point or another.

Once those clips that hold a fuse in place get hot they have a tendency to get worse and worse from then on. The metal loses its finish, the metal gets softer, if they are soldered to a pc board, one or both can lose continuity. It may feel and look like a good tight fit when its cold but as it heats up it gets loser and heats up more. (I am sure you are knowledgable of the properties of metals and how, when a metal is heated up and cooled off slowly it gets softer as opposed to if its heated up and cooled off quickly it gets harder.)

Would you provide a link to specifications on your particular Condumex pv cc?
(a link that doesn't require a code name and secret password )�  � 

OK ok, you got me. I was being a butthead in an attempt to drive a point. So, pry my eyes out with a spoon already.

Automatic Low Battery Voltage Cutoff Setpoint.
It speaks for it self doesn't it?

Hey, I am all for safety features. But, like seatbelts in cars, I am not going to rely on that seatbelt to save me in a crash, instead, I am going to rely on my defensive driving skills to keep me from having a crash.
http://www.smith-system.com/
� 
Right about here one might think, "well thats different, driving and automobile and having an off grid power system" but I don't think it is. To my mind it is Analogous.

I could have, not paid, for that defensive driving course. I could have just stuck with the free (more or less) high school drivers ed. course and had a drivers license just the same as millions of others out there on Americas highways, on Our highways.
But I didn't.
 Because I believe that along with that freedom to make choices, we all cherish so much, here in the United States of America, comes the responsibility of making the right choice.
(I wonder if this is how bureaucracies got started?)

(Oh, for those of you who have lived "sheltered" lives, that thing about prying eyes out with a spoon, in some circles thats just a way of apologizing without having to apologize. Crazy huh?)

...and here I was thinking all of this time that I was suppose to be sizing systems so that things such as auto low battery cut off wasn't even an issue. I mean to say, I thought automatic low voltage cut off switches were redundant to a properly sized system and a battery state of charge monitor installed in a conspicuous place. Boy, do I feel dumb. Its like they say, "you learn something new everyday."

Wait! Does this also mean that, when I begin calculations for sizing the; wire, fuse and, disconnect going from battery to inverter that, I should be dividing the inverters automatic low voltage cutoff setpoint from its continuous rated wattage? Or do I use the inverters nominal battery voltage rating?

If Alt-E will allow it Jon S., and while not meaning to "out do" anybody, here is a link to a more, illustrative description of what Jon C. wrote.
http://www.jamestowndistributors.com/userportal/document.do?docId=126&title=Sizing+a+Shunt+to+a+DC+Ammeter
If Alt-E will not, then...
Its funny sometimes what can clear up an understanding of how something works. Take batteries for example. Once I had read from a high school chemistry text book that, a battery doesn't store electricity, that it converts electricity into a chemical energy and stores that, battery types and their ratings were no longer a mystery to me.
 
Think about the starter motor on an automobile for a moment and how, most of them can "pull" around 80 amps at 12 volts from the cranking battery. Imagine what size of a switch would be on the steering column (picture Frankenstein's laboratory) if there wasn't an electromagnetic contactor or "solenoid switch" on that circuit.
Instead, a small amount of amps runs along a small wire to a small switch on the steering column and then to the solenoid which charges an electromagnet which in turn pulls in the large contact that carries the higher amperage through larger wire to the starter from the battery.
If you think about how an analog ampmeter, with the moving needle, works then you can see that its a tiny little motor of sorts that drives the needle. Now, imagine how big an ampmeter would have to be to read 180 amps of current on 0000 wire.
Picture, David and Goliath.
The shunt (David) knocks down the high amperages (Goliath) and cuts off his head so that the meter (Israeli army) can... Well, maybe thats not such great analogy. But, do you get the picture?

There are a multitude of inverters.
It depends largely on each particular inverter.

There are, what is known as, inverter/chargers that allow grid power to pass through while charging a battery bank, even while the bank is also receiving a charge from other sources. In the event of a blackout or if you where to just turn the circuit off the is supplying grid power to the inverter, it transfers to battery power to make vac automatically, even if the bank is receiving a charge from other sources. An example of this one is the Trace DR1512. 1500 watts continuous, 120 vac modified sinewave output, 12 vdc nominal input (or 24 vdc input - the 1524). I should point out that it will also operate from a vac generator.

Do you have a particular inverter in mind and what types of load(s) will it power ie; sensitive electronics such sound equipment or, resistive loads such as electric heat and incandescent lighting or, reactive loads such as vac motor and florescent lighting and transformers?

Could the load(s) be powered by vdc instead? Eliminating the inverter inefficiencies.

A word about sinusoidal wave forms. Pure sinusoidal wave form can only come from a spinning force. Its three dimensional. Imagine looking at a stretched out Slinky from one end. What you are probably used to seeing is a two dimensional representation of this as a smooth flowing curved wave going up and down. These low vdc to a higher vac inverters, very basically, turn the low vdc off and on so that it can be stepped up to higher vac by way of a transformer. Similar to a coil in an automobile ignition system. The points open the 12 vdc to the coil which causes the magnetic field on one set of windings in the coil to colapse and be induced on another set of windings in the coil that step up the voltage which goes to the spark plug where it shorts out with a high intensity arc.

Square wave - pretty much obsolete, best used for resistive loads. As the name implies, straight over, straight up, straight over and, straight down.

Modified sine wave - (another way of saying modified-square wave) good for most household needs but not so good for sensitive electronics or possibly some sound equipment. Imagine steps going up and down instead of squared over, up, over and, down.

True sine wave - (another way of saying ultra-modified square wave) good for almost everthing depending on the quality of its materials and manufacture, which is true for all manmade products. Many more steps up and down.

More fun with wavelengths;
http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html
http://micro.magnet.fsu.edu/electromag/java/index.html
http://www.music.sc.edu/fs/bain/atmi02/wt/sine/index.html

Hey! Looks as though you have an anniversary of sorts coming up Mr. Laughlin. As for your "mistake", I really don't see were you made any mistakes. You are doing something, somewhere that nobody has ever done before. You are the first to have a PV powered firewood bundle vending machine in Connecticut. Like a pioneer blazing a new trial, you try a way and if it doesn't take to where you need to be, then you back up and try another way.
____________________________________________________________
Posted by Ken Hall on April 24, 2009, 11:42:58 AM
Re: System requirements (Reply #2)
That machine is probably already ground fault protected. Check your owners manual or the electrical schematic for an internal GFCI.

A 20amp draw at 115V would be about 200 amps on the 12V side.  I would start thinking 24 or 48 VDC.

This is not going to be 1-2 batteries and a single panel.  You are most likely looking at somewhere between 6-12 KWH a day. Just ball parking the lower number you are looking at maybe 1400lbs worth of batteries and something above 1.5kw worth of panels.
You are probably looking at a $15K starting price and it could easily double that.

____________________________________________________________
Posted by Thomas Allen Schmidt on September 26, 2009, 02:36:37 PM
Re: Firewood vending- convert to solar (Reply #2)
Oops! It appears that I made a huge blunder in one of my calculations. I happen to think to myself while I was at a snack machine a while ago waiting for my Fig Newtons to drop, "who would want to wait 15 minutes at a vending machine for their treat?" Then it hit me, Duh! You stated that the machines motor runs for 15 seconds while delivering the bundle and in my hast to simplify the math I used 15 minutes.
Sorry 'bout that.
So, instead of an 805 amphour battery bank and a 2,000 watt PV array it should have been more like a 110 amphour battery bank and a 254 watt PV array assuming all of the other circumstances used in my last post. The lights would use more power than the motor in terms of kWh's. Getting its power from a battery and inverter assuming a 15% efficiency -
The lights = .504 kWh's per 12 hours of on time during the winter.
The motor = .03 kWh's for every 15 seconds of run time, 4 times in a 24 hour period.
So .507 kWh's or 507 watt hours divided by 24 vdc nominal is 21 amphours times 5 is 106 amphours.
507 watt hours divided by 2 hours of equivalent full rated power from a PV module during the winter months is a 254 watt PV array.
That sounds a lot better huh?
____________________________________________________________

Opinions are, a lot like bellybuttons. Everybody has one.
Maybe now at least you will place more importance on your own Mr. Laughlin. Opinion I mean, not your bellybutton. Not that are bellybuttons aren't important, I mean they remind us all of where we come from. I am gonna leave now.

There is a web site that should help you, some what.
http://rredc.nrel.gov/wind/pubs/atlas/maps.html
2797 kwh's a month, thats a pretty tall order to fill for an "off grid" system utilizing just wind.
If you were to install a wind genny rated for 10,000 watts max. in a wind speed of 28 mph then, roughly speaking, that would need to be sustained 28 mph winds for at least 9 hours a day, or some variation of that. Maybe sustained 14 mph winds, 18 hours a day. Everyday. But there are a lot of variations like, in a 14 mph wind, the genny may make less than 5,000 watts.
Also if there is one day the wind does not blow at all, battery storage for one 24 hour period would need to hold more than 90 kwh's or more than 1875 amphours at 48 vdc nominal. Thats just one 24 hour periods worth.
You may want to supplement wind with PV as well as conservation.
To give you an idea, if I were paying for my electricity at a rate of $0.12 per kwh, my electric bill would be about $7.00 a month as opposed to your $335.00 a month electric bill. I admit though, my propane is higher than normal. It performs the tasks of; refrigeration, cooking, hot water (assisted by solar), and supplemental heat. But even the LP bill averages out to about $45.00 a month.
As distasteful as it may be to some, I am quite comfortable here on our farmstead. I did have an advantage though, I learned how to live without any electricity at all for over 25 years first.
I never get tired of writting this.
From whatever beginnings one believes that mankind had on Earth, we can all agree that several thousands of years went by up to the advent of electricity, which started only about 100 years ago. Mankind flourished without electricity for thousands of years but now in just the last 100 years we cannot live without it?
There is something wrong with that picture.
Or is there?
I am sure that somebody is laughing about it, all the way to the bank. Probably the only sour note in their day is when they think about how its not illegal to live without electricity under punishment of law... Yet.

Total revenues in 2008 increased from $343.7 billion in 2007 to $363.7 billion in 2008 primarily due to the 6.7 percent increase in the average retail price despite a 0.8 percent decrease in total retail sales of electricity.
http://www.eia.doe.gov/cneaf/electricity/esr/esr_sum.html

Its understandable why RE is trying so hard to get a slice of that pie.
Good luck!

Ok, so their neighbors hated them for the loud noise they were making. They moved to China because their neighbors complained of noise? Ya, right. Are you sure there isn't another "plus" here beside appeasing the neighbors.
Why not just move to Canada or Mexico. They are a lot closer and will soon be part of the N.A.U. with the U.S.A.
http://stopthenorthamericanunion.com/index.html
Or maybe they are looking at increasing their profits by way of China's slack environmental laws, as compared to environmental laws in what will become the N.A.U.