Thomas Allen Schmidt's posts

Posted by Thomas Allen Schmidt on May 30, 2008 04:30 am

#361 -  Renewable Energy > Technical Discussion: Other > Re: Generator 12v chargeing
Would I be correct if I assumed that this 12 vdc charging circuit you refer to is the generators cranking battery charging circuit?
If I am correct in assuming this, Then I would say it is not a good idea. It would be wiser to purchase and install an inverter/charger such as the Trace DR 1500 for example.

The Trace (Xantrex) DR 1500, among others, has the built relay(s) and electronic controll circuitry that allows pass through vac power and regulating a charge to the battery bank while the generator is burning fuel. When the generator is not burning fuel the DR 1500, among others, is making vac from the vdc on demand and it has an adjustable idle mode.

This may not be the less expensive course in the here and now but thats renewable energies for you.  the renewable energies industry was not created to save us money. It was created for the same reasons as any other industry, profits. We are just supposed to believe that its okay to spend more for RE because we are "saving" the planet Earth in the process.

The RE industry is really no different than any other industry, its bottom line is profit. Whats more, if you read the news articles concerning RE there will most assuredly be a mention about government (taxpayers) money involved with R&D or incentives to create or incentives to buy. Talk about paying for something out of more than one pocket.
 

Posted by Thomas Allen Schmidt on May 18, 2008 03:39 pm

#362 -  Renewable Energy > Technical Discussion: Other > Battery sizing
Autonomy and longevity are the words.
Where autonomy is defined in terms of a political reference it still lends itself to the action of a true deep cycle flooded cell lead acid battery when referring to the entire system of a renewable energy source maintaining an adequate state of charge of that battery over several days, and in conjunction with, longevity over the course of years.

Personally, I have found that sizing a battery bank for this purpose is best done by determining the expected number of amphours to be removed in a 24 hour period and multiplying that by no less than 5. In the case of photovoltaics to also size the array to replace the same amount of power used in a 24 hour period in one clear sunny day. This at times will create some surplus PV electricity but at other times permit you to go indefinitely without polluting the air. Of course this varies from region to region.

 This keeps the bank in the top 20% state of charge effectively shallow cycling them. Which in return, during inclimate weather, gives one several days of Independence from polluting charge sources such, as the grid or a fuel fired generator. At the same time it will increase the overall life expectancy of the battery bank with proper care and maintenance.
 

Posted by Thomas Allen Schmidt on May 18, 2008 02:51 pm

#363 -  Renewable Energy > Technical Discussion: Other > Re: Replacing a battery in a set
Wow! Where to start...
Hoppecke only makes about 30 or so different batteries.
So without knowing any specifics I will answer in a generalized way.
"Testing the acid with a hydrometer" - "3 barely register anything."
Take a little of the electrolyte, about 1/4 teaspoon, from each of the three batteries and make three puddles, one from each battery on some wax paper, then sprinkle a little baking soda on them.
Do they all three "fizzle" rapidly?
If yes then the electrolyte may still be good and may not need replacing.
Have they ever had their plates exposed to air?
Have they been regularly equalized (once a month)?
Are all connection series/parallel clean and tight?
Was the "bank" sized right so that the percentage of charge never goes below 50%?
Do the stay at a low percentile state of charge for very long (2 or 3 days) without fully recharging?
Have you tried recharging just those 3?

What does the manufacturer suggest?

 

Posted by Thomas Allen Schmidt on May 18, 2008 02:10 pm

#364 -  Renewable Energy > Technical Discussion: Other > Re: charge controller question
The most basic of charge controllers simply monitors line/battery voltage and with voltage high and low set points opens or closes a contactor/solenoid.
 

Posted by Thomas Allen Schmidt on May 18, 2008 06:44 am

#365 -  Renewable Energy > RE General Discussion > Re: conversion math
Precisely.
The math of electricity deals with absolutes.
The more precise one is with the input data the more precise the answer will be.
Advertising, on the other hand, has a tendency to exaggerate. But you know this.
Key words here are - rated output.
 If the manufacturer of this product was able to achieve this "rated output" then there would have to be a test condition. Was the test condition a standard among generator manufacturers? What are the conditions?
 
A generators output is directly related to its input speed and torque values as well as any load that would be placed on it which could have an effect on internal temperatures and so on. All of this would appear to be picking nits but, you wanted to know, and the best way I know how to know an unknown is to know what the unknown is and then form an hypothesis. Then experiment to prove or disprove that hypothesis. After all Micheal Faraday didn't invent the very first electric motor sitting on his keister you know.
http://www.rigb.org/heritage/faradaypage.jsp
Not that I think you are prone to sitting on your keister or anything, its just a figure of speech.
Anyway, you will need; an amp meter, a volt meter, an rpm gauge, a power source (to spin the generator,) and a torque value gauge. You know what, on second thought, it would easier to preform another well known mathematical step that electricians use known as de-rating, which is to assume that it will not put out its advertised rating.
 

Posted by Thomas Allen Schmidt on May 10, 2008 05:45 am

#366 -  Renewable Energy > Technical Discussion: Other > Re: inverter specs
I am curious as to what you are using it for now.
I have gone through several calculations and have yet to find the correct one that gives me the same answer as yours.
480 volts from 32 - 53 watt PV modules rated at 47 Vmax. and 1.2 Imax. each.
If I divide 53 by 47 I get 1.1
If I divide 53 by 1.2 I get 44.1
Obviously 4 times 8 is 32
But how to derive 480 from 32 times 47?
4 strings of 8
8 x 47 = 376 (If 47 is the max volts then the working volts would lower)
Maybe, if you have 2 of those modules "sitting on the bench" then in a since you have 3 sets of 10 but thats still only 470 Vmax.

Its curious that you would mention these modules and there ratings if you did not feel that it is relevant to your ultimate question of, where to find an inverter to run on 1.2 amps at 480 vdc. Even more curious is that you did not mention the average expected number of hours of power production per day, averaged out over the year. I am going to guess 5. So,
32 x 53 x 5 / 1000 x .10 x 365 = $309.52
 if your lucky enough to get $0.10 per kilowatthour. Heres to sunny days.

Anyway, if your on the internet reading this then you have access to a search engine of some kind. Just type in - 480 vdc inverter - and this will get you several hits for inverters that have an input voltage that ranges from as low as 250 vdc to 480 vdc. Here is one of many.
http://www.zapsucker.com/intrface.htm
Prepare yourself, when you go on the grid with this kind of power it could make feel like your a bug under a microscope?

 

Posted by Thomas Allen Schmidt on May 7, 2008 04:53 am

#367 -  Renewable Energy > Technical Discussion: Other > Re: watt meter for DC
Thats the "rub" isn't it?
I mean we ether pay a lot for a lot or a little for a little. Ether way, we get what we pay for. Still, there are those rare occasions when we pay a little and get a lot.
When I started out it was with a relatively small system. 154 watts of PV, Trace C-30-A charge controller, and three 8-D "18 wheeler cranking batteries."
Dim lights - batteries low.
C-30-A clicking rapidly - batteries charged.

When the "future" arrived I was astonished by the TriMetric and wondered why I didn't get it sooner. The enchantment has worn off some but its still right there, in the wall by the front door under the indoor/outdoor digital thermometer telling what I need to know.

Its a wild feeling, when the TriMetric is set to display amps in/out and there are clouds coming and going. If I watch the amps in, going up and down, my peripheral vision is picking up the changing light levels from outside and it feels like I am in motion.

I am not trying to sell you a TriMetric, but if I had it to do all over again, I would have made some kind of monitor as much of a priority as the PV modules. Those first three batteries would have lasted longer.

Trojan T-105's are expected to last 5 to 7 seven years, (if sized and treated right) mine are still working on their eighth year. But I will never buy anymore T-105's. They have been good batteries but for one thing, the terminal posts break off way to easy. Sorry Trojan, but for that reason alone I am going to try Surrettes next.

God its great living in a country founded on Christianity and Democracy.
When asked, "Whose name is on that coin?" the reply was, "Caesar's"
"Then you should give to Caesar that which is Ceaser's and give to God that which is rightfully Gods, your eternal soul."
These words, or something to the effect of, were spoken nearly 2,000 years ago. During a time when mankids biggest worries wasnt energy, but what happens to our eternal soul. There is no reason why they shouldn't still be true today. Of course it would be Washington in place of Caesar. Washington being synonymous with the nations capital. There is a reason why we do not see lugage racks on hearse's.
 

Posted by Thomas Allen Schmidt on May 6, 2008 04:59 am

#368 -  Renewable Energy > Technical Discussion: Other > Re: watt meter for DC
Particularly if the 12 vdc solar system you are planing to create is charging a battery bank off grid? A wise investment for the "here and now" as well as the "long haul" is a meter such as the Bogart Trimetric.
It does not display wattage but it does display amp hours in to and out of the battery on a daily basis as well as an accumulative amp hours out. Minimum and maximum voltages. A little math and you can have your wattages.
I have been utilizing one for more than eight years.
If you consider this, don't just look at the "brochure" and price, download the manual and read through it. It will give you more detailed info about what you can accomplish.

http://www.bogartengineering.com/
 

Posted by Thomas Allen Schmidt on May 5, 2008 05:50 am

#369 -  Renewable Energy > Technical Discussion: Other > Re: Panel to converter in-line fuse size?
Buckle up!
Wire is sized according to the expected number of amps that will be running through them.
Manufactures of UL (Underwriters Laboratories) listed electricity consuming devices must post on that device the amount of electricity it consumes or in the case of PV modules what they produce.
Manufactures of UL listed wire do not have to post on the wire itself how many amps each wire can safely conduct but it does have to be posted somewhere. Typically we find these in the NEC (National Electrical Code) manual or handbook. There are so many types of wire and situations, such as ambient air temperature or conduit fill, to name a few, where the ampacity of a wire can change. All of this is in the NEC book.
That 156% that Mr. Cormican mentioned, is actually two different requirements. One is the addition of 125% to satisfy the NEC. The other is 125% to satisfy the UL.
125% x 125% = 156%
You see both the NEC and UL, individually believe that under certain circumstances a PV module can exceed its manufactures rated short circuit amperage output.

An example: We know from the NEC that #12 THHN copper wire is predominately good for 20 amps. Lets say, for example, that you have 5 - PV modules wired in parallel and their short circuit rating is 3 amps each for a total of 15 amps. #12 THHN can handle this, but we still have to add 156% for a total of 23.4 and so now we know #12 will not do. There are other factors to consider as well, but I will have to get back you on those.
 

Posted by Thomas Allen Schmidt on May 2, 2008 04:27 am

#370 -  Renewable Energy > RE General Discussion > Re: I need help Finding AWG #4 cables
That does seem kinda big. Even for a run of 60 foot. Were only talking about 17 amps right?
There should be an electrical supply house somewhere near you that will cut the lengths you need. Electrical contractors need to have some sort of supplier. Check the yellow pages. Will THHN work? As for the color, while your there tell them you need some red and green tape and you can tape each end of the same wire.
 

Posted by Thomas Allen Schmidt on May 2, 2008 04:12 am

#371 -  Renewable Energy > Technical Discussion: Other > Re: Load Distribution Block, Grounding and Enclosures
I am trying to understand your questions better by visualization. I am imagining a pop-up travel trailer with a 100 watt PV module that is deployable or maybe fixed. This in turn recharges a deep cycle battery utilizing some sort of charge control. Which in turn provides power for lighting and stuff by way of a DC rated, fused, power distribution panel.

At what wattage must the load go from 'wired to controller' to 'four terminal load distribution block' for an off grid 12v system?  We noted that the 50 watt did not require this but the 115 watt did.

Nope sorry, don't have a clue what your asking in the first question. My deductive reasoning skills seem to have eluded me there. I need something more.
Name brands, model numbers, something.

In building our mobile solar system at 100 Watts, as this unit is mobile, do we use a grounding rod or how?

Most low voltage, DC, mobile applications, off grid I know of do not require a grounding rod in Earth.

For enclosures, can fiberglass or plastic be used instead of metal?

I don't see any reason why it can't be fiberglass instead of metal.

Something I would like to point out is that most automotive electrical devices, such as but not limited to fuses and fused distribution panels are not rated for the higher open circuit voltages that a PV module can produce.



 

Posted by Thomas Allen Schmidt on Apr 30, 2008 08:36 pm

#372 -  Renewable Energy > Technical Discussion: Other > Re: Help designing system for internet servers
I like restricting any engine driven generator usage to long periods of inclamate weather.
So to size a battery bank.
20 amps x 120 volts = 2400 watts.
Does this all run for 24 hours?
24 hours x 2400 watts = 57,600 watt hours -
57600 watt hours / 48 volts = 1200 amp hours
To give your batteries a certain amount of autonomy and longevity size it to stay in the top 20% depth of discharge.
1200 x 5 = 6000 amp hours total capacity at 48 volts nominal. If it all runs 24 hours a day like this, this would give you 3 to 5 days of autonomy, then it might be time to fire up the generator, unless the PV array is sized right.
1200 amp hours x 48 = 57600 watt hours.
57600 watt hours / 5.6 hours a day = 10000 watt PV array at 48 volts nominal, at the very least.
 

Posted by Thomas Allen Schmidt on Apr 30, 2008 07:52 pm

#373 -  Renewable Energy > Technical Discussion: Other > Re: no batterys
Sure, hydro gennys do this all the time. There quite few famous ones. Lets see, there is the Hover dam, uh, Niagara falls to name a few but of course they do have resistor banks instead of battery banks.
Have you ever monitored the output voltage of the hydro genny? Is it consistently between 11 to 14 vdc under load? not much lower or higher than this and the inverter could shut down. You see, the thing is when it get loaded down it slows down and the watts go down. As load is removed just the opposite happens. So another question would be is the load consistant?
 

Posted by Thomas Allen Schmidt on Apr 30, 2008 07:33 pm

#374 -  Renewable Energy > Technical Discussion: Other > Re: What size battery bank for large Inverter?
I am going to assume that the 230 vac is not 120/230 single phase 60 Hz. but just 230 vac 50Hz.
The inverters maximum rated output is 10,000 watts.
10,000 divided by 12 vdc nominal would be 833 amps.
This 833 amps is just not feasible.
This would call for nothing less than parallel 500 MCM times 2.
I have a few questions for you.
What size wire is feeding this inverter from the batteries?
Your batteries have a total of 550 amp hours at 12 vdc nominal, right?
At best this would give your inverter 6600 watts for 1 hour at 240 vac. Of course all of this is dealing with the absolutes of math. I n the real world you would only get a fraction of this. Probably about 80%. As amp hours get used up battery voltage goes down quick even with the best true deep cycle batteries.
 

Posted by Thomas Allen Schmidt on Apr 28, 2008 01:46 pm

#375 -  Renewable Energy > RE General Discussion > Re: New to Solar--have a few questions!
I second John D's advice on pure sinewave inverters.
 Only in keeping true to form I have to say they are really not so pure.
 Square wave, modified square wave, and "pure" sine wave inverters are anything but sinusoidal. They are stepped imitations of sinusoidal waves. When we represent sinusoidal waves for demonstration purposes we create a 2 dimensional wave but in real life a sinusoidal wave is 3 dimensional.
Imagine a Slinky stretched out long.
 This 3 dimensional sinusoidal wave can only be achieved by a revolving force. Anything else is just an imitation. But in the case of electronic "pure" sine wave inverters, its a good enough imitation. Certainly better than the modified square wave or square wave inverters. The following is the best repsentation of what I am writting about. It actually shows a sine and cosine waves out of phase with each other much like the 120/240 vac single phase power provided by the power companies for residential use. For three phase power such as 120/208 vac used in commercial applications or, 277/480 vac used for industrial purposes, or even 120/240 vac 3 phase with a high leg typically used in rural agricultural areas, just imagine a third wave out of phase with the other two.
http://www.rkm.com.au/ANIMATIONS/animation-sine-wave.html
Here is another place to have some fun. http://micro.magnet.fsu.edu/electromag/java/index.html

Well I guess I've gone on long enough about that. The Sun is "back out," I am going to go weld some steel together now, using four 12 volt batteries wired in series for 48 vdc.
http://www.offroad-review.com/product_reviews/READYWELDER/READYWELDER.htm
 

Posted by Thomas Allen Schmidt on Apr 27, 2008 07:13 am

#376 -  Renewable Energy > RE General Discussion > Re: New to Solar--have a few questions!
www.homepower.com
Speaking for myself, a subscription to Homepower magazine was one of the greatest investments that I made towards utilizing photovotaics in order to have electric lighting instead of candles and kerosene lamps.

A copy of the National Electrical Code came in real handy. Article 690 in particular but not limited to it. Something to remember about this is that the NEC is an institution of the NFPA National Fire Protection Agency. www.nfpa.org

You may already be familiar with Ohm's Law.
http://www.elec-toolbox.com/main.html

Like you, I started small. 2) Solarex MSX 77's, 2) 8-D "Big Rig" cranking batteries, 1) Trace C-30 A charge controller and, 2) DC rated fused disconnects. All for DC lighting and a radio.

I was fortunate in the sense that both of my parents were knowledgable of electronics, to put it mildly. This means I grew up hearing words like Ohm's Law and learning about electricity and the math behind it.
Local community colleges sometimes offer beginners electrical wiring classes.
Not only will you learn what they have to teach but you have the potential of making friends with electricians. That alone could be worth the tuition fee. Just being exposed to the words and practices of electrical wiring give you something to extrapolate from. Kinda like how you want to start small with your PV system and learn as you build it bigger and better. Electricians aren't so bad once you get to know them. Now there are some licensed electrical contractors out there I don't care to much for but I guess that goes with any type of contracted work.

One more for the road. http://photovoltaics.sandia.gov/docs/John_Wiles_Code_Corner.htm
 

Posted by Thomas Allen Schmidt on Apr 22, 2008 04:50 am

#377 -  Renewable Energy > RE General Discussion > Chef Boyardee
Chances are a lot of you have heard of that name before.
What I would like to know is the name of the guy or gal that had the idea to grind the meat and fat of a hog, stuff that into its intestinal tube, then hang that up in a cool, dark, and dry place until it grew a little mold, then cleaned the mold off and fryed it up in a cast iron pan. This person was a genius.
Sounds gross when put this way but for those of you who have eaten cured pork sausage fryed you know what I am talking about. Even more of you have experienced cured ham. Same principal. Smoked beef. The list goes on. When you cannot get fresh vegtables, do you get them from a jar or a can?
Now ask me, "what does any of this have to do with renewable energies?"
http://www.kountrylife.com/contents.htm
Just because we are alive today on this planet doesn't mean we are the only ones that have ever lived on this planet. We can learn a lot about living on this planet from those that lived here before us.
 

Posted by Thomas Allen Schmidt on Apr 22, 2008 04:22 am

#378 -  Renewable Energy > RE General Discussion > Re: For those that have successfully gone off-grid, how many watts?

If you look at how rural electrification evolved on the grid starting around the early 1900's some of the first residential utility services were only 30 amps at 120 vac. Now you would be pressed to find a new home with nothing less than a 200 amp service at 240 volts.
For me personally I lived for the better part of twenty years without any electricity what so ever and now I live  with a 1000 watt PV array. So what? I don't need them per say I simply wanted them. You could ask 100 people and get a hundred different answers. Bon appetit!
Oh! Thats it inst it, your forming a concensus?
How much wattage do you need/want?
If I may offer a little advice? Try living without electricity for a while and you might realize that you can live without it, or at least a lot less of it.
It could be said that there are four modern day energy essentials in life; cooking, heating, refrigeration, and transportation and all of these with the exception of refrigeration (they perserved) were accomplished by our ancestors for thousands of years before us, without electricity.
 

Posted by Thomas Allen Schmidt on Apr 19, 2008 02:46 pm

#379 -  Renewable Energy > RE General Discussion > Re: Will the investment have a real return?
One could "crunch" numbers in order to come up with a few fixed sums that may or may not justify spending a small fortune on renewable energies, but in the end one just has a singular choice that amounts to taking a "leap of faith."

I have often heard it said or have seen it written that the cost of a renewable energies system to supplant conventional electric utilities cost the same as a life time of electric bills, if certain large electric loads, such as, but not limited to, cooking are changed over to liquid Propane or Natural gas.

Reducing the overall electric load is the first and formost consideration. This is where the strength of your faith may get its biggest test. Think of faith as a verb instead of a noun. An action instead of a thing.
 Mankind not only just lived, on this Earth for thousands of years, without the electricity we know today, but flourished. Now what does mankind have?
The automobile and electricity came into the scene at about the same time that global human population began its explosion. And of course the pollution that would ultimately result from all of it. Pity about Earth.

Lets do a little math for the fun of it. $0.23 per kWh huh? Your probably already somewhat conservative with your electricity so I am going to guess that you use 1000 kwh's a month. That would be $230.00 a month. $2760.00 a year and for, I don't know, 45 years? That would be $124,200.00. that is a nice little stack a jack! Of course your "mileage may vary."
The point is you may have to reduce that 1000 kWh's by at least half first. Then consider making your own power. I cant really say for sure because I do not know your situation entirely. Its still going to take a leap of faith by you.

Buyer beware Renewable energies is a sellers market. You will be paying top dollar for your kWh's anyway. A lot depends on how long you live on this Earth.
 

Posted by Thomas Allen Schmidt on Apr 4, 2008 02:04 am

#380 -  Renewable Energy > Technical Discussion: Other > Re: Amp draw on storage batteries.
You must be a lucky person. Because, out of all the billions of billions of galaxies in this endless universe, you just happen to be in the right galaxy where there is a solar system with a single planet in it with sentient beings that eat metal (sodium and potassium)and you are on the right planet to get that question answered. Generations of people have come and gone for thousands of years here on the planet Earth, each one having played an important part in the principles regarding the answer to your question.

One of my own experiences with batteries was the understanding that its a chemical reaction. The battery does not store electricity. I know, amazing right? But true. The battery changes electric energy into a chemical energy and stores that when re-charging and vice-versa when dis-charging.
http://www.corrosion-doctors.org/Biographies/VoltaBio.htm

Did you know that one amp is made up of of billions of billions of electrons but those electrons do not have the distinction of becoming an amp until time has passed?
http://www.corrosion-doctors.org/Biographies/OhmBio.htm

The history of humans on the planet Earth is full of names that have become synonymous with with the very lives we live in todays nuclear age. Names such as; Ampere, Faraday, Galvani, Hertz, Joule, Ohm, Tesla, and Volta just to name a few. In the field of medicine there is, what is know as an MRI or Magnetice Resonance Imaging and, as the name implies, it utilizes a very large and powerful magnet. These magnets can have different strengths according to what is to be imaged, wether it is a living patient or not, and the term Tesla is used as a degree of magnetic field strength.
http://www.corrosion-doctors.org/Biographies/AmperBio.htm

Know the load(s). For example: if I had a load of 2400 kW h's (kilowatt hours) at 120 vac (volts alternating current) and I want to know what that was in amphours at 24 vdc (volts direct current) I would simply multiply 2400 by 1000 and divide the answer by 24.
Watts is watts. There is no distinction between vac and vdc where watts are concerned in calculating loads.
So, know your load. All those billions of billions of electrical gizmo's on Earth typically have a label on them that will show at least two things, volts and amps or volts and watts. Less likely would you see amps and watts or even all three. Don't despair. As long as you have at least two you can figure the third by simple multiplication or division. One more critical item you must have is time. Liner time is critical to all electrical calculations of this type.
http://www.corrosion-doctors.org/Biographies/WattBio.htm

As for your other question.
120 x 10 = 1200
4 x 12 = 48
1200 / 48 = 25
25 x time? =?
I inverter inefficiencies can run as high as 15%. Also battery autonomy and longevity are important. Once you have the right amphour capacity needed multiply by a factor of 5. This will keep the batteries in the top 20% of full charge most of the time.
http://micro.magnet.fsu.edu/electromag/timeline/index.html
 
There was one of those sentient beings that said something rather intelligent once. I cant remember which one it was but he said something to the effect of "give a child a fish, and they eat for a day. Teach them to fish and they eat for a lifetime,"
http://micro.magnet.fsu.edu/electromag/java/index.html

When you look up at the stars at night, do you every feel a perception of depth in our universe? We know that molecular cohesion is what holds elements together as compounds, so couldn't gravity be constituted as molecular cohesion?
http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/index.html


Pity about Earth.


 

Posted by Thomas Allen Schmidt on Apr 2, 2008 08:42 pm

#381 -  Renewable Energy > Technical Discussion: Other > Re: Newbie at a small public high school converting an electric golf cart ...help!
I am guessing all 6 - 6 volt batteries are wired in series for 36 volts nominal and that they are of the 220 amp hour (@ 20 hour rate) range like the Trojan T-105's?
It would be simpler if they made these golf carts so that the battery bank could be easily removed (like some forklifts) so that, while one bank is being charged by photovoltaics during the day the other can be in use during the day, but thats nether here nor there, so...

If your interested in re-charging directly from a PV array it will ether take a very large array with surplus electricity before and after the re-charge or the golf cart can only be used at night because it will have to charge during the entire day.

A start would be to know how many amphours are removed from the battery bank during a typical days usage.

If I took a guess and said 100 amp hours then -
36 x 100 = 3600 watt hours
that 3600 watt hours would then have to be divided by the number of hours of equivalent full rated charge available per day in your region.
http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/
 If I guessed and said 4 hours per day averaged out over a year then -
3600 / 4 = 900 watt PV array at 36 volts nominal, but, this is bare minimum and it would take all day to re-charge the golf cart on the best days. So you can see why a very large PV array might be needed in order to re-charge the golf cart in a shorter period of time which would then result in a surplus of electricity before and after the re-charge. A second or third golf cart might be an option. One in use while the other(s) re-charge.
It makes a grid intertied PV system to offset the usage of coal fired power plant electricity look more inviting. Just keep in mind that this would involve; permits, contractors, and inspections but there maybe a benefit of tax incentives to offset the cost of them. http://www.dsireusa.org/library/includes/map2.cfm?CurrentPageID=1&State=NC&RE=1&EE=0
I geuss its true what they say, "theres no such things as a free lunch."
http://www.motherearthnews.com/Nature-Community/1982-09-01/Take-an-Eco-Village-Vacation.aspx
 

Posted by Thomas Allen Schmidt on Apr 2, 2008 07:54 pm

#382 -  Renewable Energy > RE General Discussion > Re: Successful Systems
You may already know this one but here it is any way.
http://otherpower.com/
They have a discussion board as well.
 

Posted by Thomas Allen Schmidt on Apr 1, 2008 05:20 am

#383 -  Renewable Energy > RE General Discussion > Re: wiring solar panels together
It kinda tuff to say for sure without knowing which charge controller you are referring to. If it has more than one set of positive and negative PV input terminals. Sometimes, single terminals can legally (NEC) accept two wires. In parallel each PV modules wire should be fused on the positive side, in series there is only one positve to fuse. Then they can be combined by way of a combiner block or maybe even DIN rail terminals with factory jumpers. This allows you to take one bigger wire to the charge controller. The same is done with the negative wire but the fuse is not necessary. Just make sure of the electrical ratings of what ever you use. (I have grown accustom to looking at electrical ratings of everything I see. Its become a habit of mine.)
http://www.curtisind.com/products/din/dinhome.asp
Automotive type fuses can work, just be sure that the voltage ratings are compatible with the open circuit voltages of the PV module. Note that, where as fuses and breakers add a degree of protection for a device, their primary purpose is to protect you and your home, or whatever, from fire. If, for example, a wire is sized to small for its amp load and its not fused correctly, the wire will get hot. Sometimes hot enough to set its insulation and anything else near it on fire. Loose wires on a terminal after the fuse can get hot, even the negatives.
The NEC National Electrical Code is an institution of the NFPA National Fire Protection Agency. You might have seen this acronym NFPA on such things as fire extinguishers.
http://www.nfpa.org/
It might seem like I am excessing (is that a word?) about this but we are on a public forum afterall.
Thats enough about that. I take it you have the GSE 6 watt PV module?
Rated amps 0.38
Rated volts 15.8
Open circuit volts 23
short circuit amps 0.45
When sizing wire use the short circuit ratings of a PV module and add 156%. That makes 0.70 amps. Then you can go on to the line loss calculations, but I gather that all your lines will be short?
 

Posted by Thomas Allen Schmidt on Apr 1, 2008 03:50 am

#384 -  Renewable Energy > Technical Discussion: Other > Re: Cb30-Air 30A Breaker for Air Turbnies
Don't know for sure. Never held one in my hand. Looking at picture provided by our host, it looks as though it doesn't mount. It looks as though it is wired in line, but they offer a protective boot. Maybe the boot mount. Never held one of those ether.
 

Posted by Thomas Allen Schmidt on Mar 31, 2008 05:46 am

#385 -  Renewable Energy > RE General Discussion > Re: wiring solar panels together
Some of the more general rules of thumb that I have learned are;
 1 - Series wiring of PV modules will involve connecting the Positive terminal of one module to the Negative terminal of another module and so on. This will cause a doubling in voltage but amperage stays the same. The more modules the higher the voltage.
 2 - Parallel wiring of  PV  modules involve connecting the Positive terminal of one module to the Positive of another module and like wise the Negative. This will cause the voltage to stay the same and the amperage to double. The more modules the higher the amperage.
3 - Its been said/written more times than one that only like PV modules should be wired into an array.
4 - Learn the Code! Wire size, type of wire, as well as conduits and means of fusing and disconnect, grounding are all very important! The best advice I can give you here is to ether get yourself a copy of the 2008 NEC (National Electrical Code) or at least make friends with an accomplished electrician who allready has one and knows how to use it.
As for the links you asked for;
http://www.homepower.com/home/
http://photovoltaics.sandia.gov/
Well I am running out of time here. These two should give you a good start in the right direction. If you have any specific questions, I would be glad to help. Despite what you made have read at some of these PV websites, its not brain surgery or anything. A lot of the electrical calculation are simple math and knowing the limitations of the electrical products available.
 

Posted by Thomas Allen Schmidt on Mar 24, 2008 07:55 am

#386 -  Renewable Energy > Technical Discussion: Other > Re: Charging Batteries from PV - Balance the Relationship
Technically one could charge as many batteries as one wants. Its what is taken away from them that has to be replaced in the time allotted that would make all the difference in the world.

175 watts at 12 volts nominal would be 14.5 amps times 4 hours a day would be 58.3 amp hours a day. Personally I would like to keep a battery in the top 20% of full charge so, if I were to assume that the load on the batteries would be no more than 58.3 amp hours divided over 4 hours then - 58.3 times 5 would be 291.5 amp hour capacity. I would say 3 - 105 amp hour batteries at 12 volts nominal... nothing else considered. Hope this helps!
 

Posted by Thomas Allen Schmidt on Mar 24, 2008 07:19 am

#387 -  Renewable Energy > RE General Discussion > Re: Area Calculators?
I am just a little confused by your question so, please, bear with me.
At first I thought you wanted to know how to figure the area of an equilateral triangle, but then I thought, no, everybody that has graduated high school or its equivalent knows how to do that. The simplest being; half the base times the height. For those that may not have graduated high school yet or perhaps were out sick that week - http://www.clarku.edu/~djoyce/trig/area.html

I then remembered seeing a photovoltaic modules that was actually built in the shape of a triangle.
http://www.renewableenergyworld.com/rea/partner/products/view?id=22184
But now we need some dimensions. Now that we know there is such a product I am reasonably sure that Sharp builds corresponding square PV modules to mate up to the triangular PV modules and it would be reasonable to assume that Sharp would have an area calculator for there triangular PV modules systems. Wow! I think I know now what your are looking for and its not easy. So far I have not been able to find the corresponding module or anything except dimensions. My best guess would be to contact www.sharpusa.com with your specific diemensions and ask them. Evidently its a big secret they want to keep for themselves.
 

Posted by Thomas Allen Schmidt on Mar 16, 2008 12:26 pm

#388 -  Renewable Energy > RE General Discussion > Re: i solved the energy crisis- i dare you to replicate my experiment
Obviously, in a time when there was only 100 million people it would not have been so much of a problem for a million people world wide to walk down to a river and wash their clothes, take a bath, maybe even catch the days meals.

Now, in our present time, that there is 6.5 billion people, this would be out of the question. There would be a billion people world wide doing these things at one time pretty much ruining the rivers. But these billions of people are still washing their clothes and everything else. That much has not changed. (Have you seen the Hudson river where it empties into the Alantic lately?) NasTy.

By the same token what we are doing to deal with the differences created by having so many more people in such a relatively short period of time is still just as detrimental to the environment in a myriad of other ways as it would be if we were still doing things as mankind did them thousand of years ago. Its a give and take scenario. Its not a billion people actually washing their clothes in a river at one time but the impact of a billion people washing their clothes at one time by todays methods is just as harmful.
We have only mechanized the process but the natural resources consumed had to come the Earth all the same and what goes back into the Earth might even include toxins.
I am "speaking" of course about the mining of, the transportation of metals and oil and coal. The refining of these resources into viable products. The paints and lubricants as well as detergents. The cutting of trees and the processes of make papers and card board. The water deliver and disposal systems. Disposing of trash from packaging. I could go on and on.
 Its no different with renewables. The energy "harvested" may be clean and natural but the natural resource to build the "harvesters" had to come from the Earth all the same and they have to go through all the same processes. Recently, PV module prices went up because of a shortage in raw materials. Unless I am horribly wrong those "raw materials" didn't magically appear by somebody wiggling their nose back and forth. And all of this isn't dealing with the amount of energy being utilized its only offering another alternative to the way they are utilized.
 All be it, in a more environmentally sound way, but still perpetuating the same energy usage. Much in the same way that washing machines and dryers and water pumps and septic systems and all of the processes to create, run, and maintain them have dealt with washing clothes for the masses as opposed to everybody running down to a river.

I have read that the Earth could support 12 billion humans, but what wasn't written was for how long it could stay that way. Again, I am not bashing renewable energies, I am only speaking a truth that some people would rather not hear. At this point conservancy is the only clear option, but I fear with so many people demanding from the Earth (in more ways than one) its only a matter of time before the Earth has to correct the imbalance, and the decision that mankind cannot or willnot make, to restore life back to a natural order from the manmade order, will be made for us. I pray that I am wrong.
 

Posted by Thomas Allen Schmidt on Mar 16, 2008 06:07 am

#389 -  Renewable Energy > RE General Discussion > Re: i solved the energy crisis- i dare you to replicate my experiment
Once again it would seem that the point was lost.

The real "problem" here is not where the energy comes from but how much energy is being used.

Those without the benefit of open mindedness might have the impulse to conclude that I am bashing renewables but I am only pointing out that renewables are perpetuating this so called "energy crisis."

The "problem" is the rate at which humans are populating the Earth. An increase of 4.5 billion people in just the last 100 years, where it took thousands of years to reach 2 billion before that.

In a sense, we human are waging war with the planet Earth for control of its natural resources. Not out any desire to do such a dastardly deed but by shear numbers of people alone.

It would be a pity if the Earth lost because then we lose too. I should add in here too, that we are not going to have energy of any kind, without consuming a natural resource of some kind.

Once in the wind a wind genny can produce electric energy from the motion of the wind, but as far as I know it did not appear there from a puff of smoke. Humans put it there and they had to consume energies of many different forms, not just to install it but also to maintain it.

When I hear or read the phrase "Energy Independence" I envision independence from energy, not just an independence from this or that nation for its natural resources.
 

Posted by Thomas Allen Schmidt on Mar 13, 2008 05:23 pm

#390 -  Renewable Energy > RE General Discussion > Re: i solved the energy crisis- i dare you to replicate my experiment
I have often wondered why, when we build things that consume energy, we build them with on/off switches.
There must be a point to these devices.
Discovering a means to end this so called energy crisis, even renewable energies in its own fashion, may not be a blessing, but an unleashing of something far worse than the existing energy crisis.
For thousands of years mankind had no need for the amount of or types of energies we utilize today, or the natural resource we consume to produce those energies, but since their discoveries within the last five hundred years or so, we simply cant get enough of them.
I am not advocating for the established energy infrastructure. Oh no, the last thing I want to see is another coal fired or nuclear powered electric plant. Nor do I want to see internal combustion automobiles belching toxins into the air I breath.
 But creating other ways to keep chugging down the same track of energy usage, no matter how environmentally benign they may be, is not dealing with the problem. It only cures a symptom.
The problem lies within each and everyone of us. We have, I think, some sort of psycho semantic neurological disorder that stops us from reaching out and using that off switch.
Don't believe me? Got a main breaker on your home? Go to it and try to turn it off. Easy right? Now leave it off. Through the keys to your petroleum fired automobile into the trash and leave them. Cant do it can you? Neither could I and neither could the other six billion people on the planet Earth I wager.
Now you know, the rest of the story.
Good day.
 

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