John D's posts

Harold,

You claim to have a non-fuel electric engine, but your website claims that principle of operation has something to do with electro-magnets. Electro-magnets use electrical energy, in other words, FUEL.  Right? 

 

I understand.

The loads that you've mentioned are all low-power, and so you wouldn't need a big (expensive) sine-wave inverter for them. A small one, powering small loads, would be more efficient than a large one anyway. You could still power-up your 1500-watt MSW inverter for larger loads of course.

If a small pure sine wave inverter is still beyond your budget you might want to get a radio and lights that can be powered directly from your golf cart batteries. You might also consider rechargable batteries for your radio, and a charger for those small batteries.

I hope this helps.

John
   

I suspect that you're using a Modified Sine Wave Inverter.  The solution then is to switch to a pure sine wave inverter.
John

As a result of a family emergency I had to drive about 1500 miles this week.  Because of Ike, I had no choice but to pay for gasoline at a much higher rate than I've ever seen.  Gasoline prices now seem to be dropping a bit. 

I will gladly continue to use my spare funds to buy solar panels, with the hope of someday using solar energy to charge an electric car.  I'm tired of being screwed by greedy oil companies.  What was the justification for that price spike I wonder?  I'm tired of enriching people who don't give a damn about my life, except for maybe converting me to Islam against my will.

There are those who will tell you that it is impractical to try to run an electric car off of a solar array. Don't believe it. The media is not likely to report fairly and honestly out of fear of offending car companies and dealerships, big advertisers.  You won't get much help from politicians because they get contributions from oil companies.

I'm a little mad right now, and feeling like I was taken advantage of while I was vulnerable.  But this experience serves as a reminder to keep moving forward, and not to depend on government to do it for me.   
   

And make sure you have HEAVY wire (maybe 4 or 6 guage) from the batteries to the inverter.  Keep it as short as you can.  With a significant load on the inverter, you're going to have high current there.  For example:  A 500-watt AC load will result in about 50-amps of DC current flow, assuming you have a 12-volt DC to 120-volt AC inverter. 

I agree that we need government involvement, a good plan, and a substantial financial commitment.  But because politicians get so much support from oil and coal interests, I'm not sure that's going to happen.  We as individuals need to lead the way, and not be discouraged by those who want us to believe that there is too little benefit for the cost of alternative technologies.  That is simply not true.  We can do it, we should do it.  We're lucky to have discussion sites like this one, and various websites and blogs that help show us how.  This isn't the 1970's; there's a lot of good equipment out there at reasonable prices.  Now is the time to show the politicians how it's done.       

Consider a manual or automatic Transfer switch.  I have my refrigerator wired into an automatic transfer switch (Iota ITS 30R) so that if one power source fails, the other kicks in automatically.   

I'll take a stab at it:

The well pump requires 2860 watt/hours.
That's 13amps X 110volts X 2 hours.
Add 300 watt/hours for lights.
That's 3 lights X 25 watts X 4 hours.
Total needs = 3160 watt/hours each day.

Lets try 8-100 watt solar panels & 4 hours of sunlight.
That' 800 watts X 4 hours, or 3200 watt/hours.

Let' shoot for enough batteries to last one day.
First convert watt/hours to amp/hours by dividing:
3160 divided by 12 = 263 amp/hours.  You don't want to discharge batteries beyond 50%, so double the amp/hour rating, or 526 amp/hours.  You can get by (for one day) with 5-105amp/hour deep cycle batteries.
 
You could get by with less batteries of course, especially if you run the well pump during the day when the sun is shining, avoiding using it at night.

That well pump represents a big load, 13 amps X 110 volts = 1430 watts.  You'll need an inverter big enough to handle that, plus any lights you have running at the same time.  I don't know much about well pumps, but some motors have a high starting current, which means you'll have to make sure the inverter can handle that as well.  Maybe you could look into a well pump that draws less current.

You'll also need a charge controller, wire and safety devices, and panel mounting hardware.

Keep in mind that the design I proposed does not take into account system losses and inefficiencies, or extended periods of cloud cover.  I don't mean to discourage you, but this will be a pretty substantial system.  Good luck!

 

Thanks for the kind words.  I'm glad you found the information helpful.  If you ever get down-state, look me up.  John

This information may be helpful:

http://solarjohn.blogspot.com/2007/02/mounting-solar-panels-on-your-roof.html

John

I would REALLY like to hear more about these 22 variable power sources. 

I think you're on the right track with dc conversion.  What you do from there depends upon how you want to use the available output.  Perhaps you can connect these sources in such a way that results in a voltage and current levels suitable to apply to a charge controller.  The useful work, therefore, would be battery charging.   

Keep in mind these facts:

In a series circuit, the voltage will be the sum of each individual voltage, and the current will not be any greater than the current producing capacity of the lowest-current power source. 

In a parallel circuit, the current will be the sum of the current of each individual source, but the voltage will tend to be the same as that of the lowest-voltage power source.  (Voltage will rise and fall, depending on the size of the load).

You may want to create a series/parallel circuit in order to get the voltage and current characteristics you'll need.  It seems that you'll need more than the 22 sources you've listed if you want to power a charge controller.  Please provide more information about the power sources.

John

You shouldn't connect together two battery banks of different types and ages.  Doing that will weaken the stronger of the two banks.  Knowing this, I decided to use a switch for my two battery banks.  I can switch in bank 1, bank 2, or both.  I usually only connect the stronger of the two banks to my charge controller/inverter.  I connect both banks when I want to charge them simultaneously, or when I have a grid-power failure and I need the extra power. The switch is heavy-duty, made for this purpose.  Check the Alt-E store, they probably carry it.  Otherwise, a camper or boat store will have it.
 

Taylor;

If you need to create a working model, a hydro-generator might be the easiest to create.  A small permanent-magnet motor could be used for the generator.  Make and attach a paddle-wheel, or an impeller with spoon-shaped spokes.  As you open a water valve, the force of the water turns the impeller, creating electricity.  Use a small light bulb, or a voltmeter to show that electricity is being created.  Good luck!

Go to the website:  www.kilowattours.org and get the video by Jeff Barrie called:  Kilowatt Ours, A plan to re-energize America

You'll love it!

John

The current "peaks" you've observed may be the result of what some people call "Edge of Cloud" events.  It is called that because momentary performance peaks have been observed as the sun emerges from a cloud. I believe that these current peaks are the result of sunlight suddenly hitting panels that have had a chance to cool down while the sun was behind the cloud.  If you look at the spec-sheet for your panel, it shows that improved performance with cooler temperatures.  Others may have different explanations, but this is MHO.

I have 5 (85-watt) kyocera panels in parallel, and I should see current readings of no more than 25.1 amps.  I've seen peaks in excess of 29 amps last winter, but not more than 26 amps during on any recent hot summer day. 

So, to answer your question, I believe that you'll continue to see those current peaks, especially in cool weather. 

John
 

The biggest expense will be for the solar panels.  As long as you buy panels that won't soon be discontinued, you can buy more later when you move from the trailer to the house.  Still, I like Ken's idea:  Learn from your small system, then sell it and start with all new equipment. 

I don't use a Xantrex controller, so I'm not sure of the details, but with mine it's just a matter of changing a couple of internal switches. 

Robert,

One of my primary reasons for installing PV was to have a backup system in the event of a grid power failure.  Because of my system I was able to keep food from spoiling, and stay comfortably in my home when many of my neighbors had to go elsewhere. 

People shouldn't get hung-up on "payback" issues.  Do you consider payback when you buy a car or clothes?  Of course not.  Do it because it's the right thing to do, for a variety of reasons.

I looked at your gallery Karen, and I'm really impressed and somewhat jealous.  I would move to a remote site and do something similar if only I could talk my family into it.  I have a small off-grid system, but I live in the suburbs with all of the normal services.  I can't say that I know what it's like to live off-grid.  I only experience off-grid living for brief periods when the grid fails.  I hope you'll keep posting so that folks like me can better understand real off-grid living.  Thank you!

Solar Gary's website is a good source of information on this topic.  www.builditsolar.com

John

James,

John B has done a good job in answering your question.  Others have provided you with some good design and system hardware information.  I would just like to add that using power directly from the solar panels to power a load is much more efficient than storing and retrieving it with batteries.  So, IMHO, you should make sure that you have enough PV to fully power the load, with enough left over to fully charge your battery each day. Considering your smallish load, you're not going to be spending that much on batteries anyway.  Personally, I would start with one 80 to 100ah battery, see how the system performs for a month or two, and add another battery if necessary.  But hey, that's just me.   

Thomas,

Yes solar panels are expensive, but once you've bought and installed them they should last for 25 years or more. I prefer to build my system now, rather than to wait and hope for a price reduction.  With this crazy run-up in gasoline prices, you just never know what will happen in the future.  I don't want to be in a situation where PV panels are in such great demand that they're hard to get at any price.  People sometimes talk about the payback of solar PV, which IMHO is absurd.  In addition to cutting your costs for electricity, putting up PV gives you protection from grid power outages.  It can prevent your food from spoiling, protect your property, keep your communications working, etc.  It's hard to put a price on those things.

Sure, I wish the cost of solar panels would go down, but I won't let their high cost prevent me from achieving my goals.

I agree that there are too many variables.  Maybe your least expensive option would be to get a Marine Deep Cycle battery from your local big-box department store.  Keep in mind that for best battery performance (life), avoid discharging it below 80% of capacity. 
   

I don't think you can do that with the Exeltech XL series because you won't be able to maintain the phase relationships.  I believe you would have to go to the Exeltech MX series of inverters.

The question you should be asking is "how do I prepare for the future?"  The sudden surge in oil prices, and the effect that this has on other things we buy, should be a sign that we should act now, before it's too late.  George W has a horrible environmental record, but has installed all sorts of alternative energy systems at his ranch.  That should tell you something.  Check this out:  http://www.ecorazzi.com/2007/02/19/president-bushs-texas-ranch-is-off-grid-eco-friendly/
IMHO You don't need a $35000.00 system.  You need enough PV to keep you comfortable and safe in your home, and to help you prepare and preserve food. You might also think about growing and raising your own food.  Or, you could simply do what many people do; hope that things never get that bad, or hope to be rescued if they do.  It's your choice.   

I have an Exeltech 1100/12v inverter and I love it, but I have no experience with the Xantrex Prosine.  I considered both inverters before I selected the Exeltech.  I chose the Exeltech because its made in the USA, has a little more power, and is less expensive than the Prosine.  

Other things to consider:

The Exeltech has a thermostatically controlled fan. In my application the fan seldom runs, and so the inverter is quiet.

The Exeltech has very good line and load regulation, with little distortion.  My TV has a streak-free picture, with no audio noise, since I started using the Exeltech.  

The Exeltech switches on very quickly, an important characteristic when using this inverter with a transfer switch.  The Prosine takes 2.5 seconds to transfer when using the power save setting.  If this is not a problem in your application, then it is a good feature.  Otherwise you might need to sacrifice higher no-load power drain for speed.  I believe the Exeltech uses 10 watts (no load) with an option, not 20.

A remote switch can be wired to a terminal strip on the rear of the Exeltech, but I don't believe it accepts AC wiring.

Hope this helps.

John

I agree that a battery monitor is a good investment, but I must confess that I haven't bought one yet.  I keep careful watch over my system manually, with a Digital Voltmeter.  I also use a data logger now and then.  I usually set it up to take battery voltage readings at 5 minute intervals.  After about a week, I download the information to my computer for display or printout. It is interesting to watch as the voltage begins to increase as the solar panels get morning sun, and watch it decline as the sun goes down in the evening.  I watch the effects of clouds, and of loads switching in and out.  Most importantly, I watch to make sure that my batteries are getting fully charged, and that they don't discharge too deeply.  It's easy to see when the charge controller switches to float mode.  I can also use it to monitor the voltage from my pv array, although that information is not as useful.  My data logger is not as accurate as the DVM.  You can find more information about the data logger I use at:  http://www.microdaq.com/lascar/usb/el-usb-3.php

John

Since the existing batteries are less than one year old, I wouldn't hesitate to add more batteries of the same type.  That would be the least expensive route.  I've used the same type of battery, and true deep-cycle or not, they're pretty good for the money.

If you decide to build a new battery array, you might consider adding a switch so that you can connect bank 1, bank 2, or both.  That's what I did.  It is more work though.  I normally have the new bank switched in, and I have to remember to charge the old bank once in awhile.  Here's a diagram:  http://solarjohn.blogspot.com/2008/05/my-latest-off-grid-pv-system-upgrade.html

A shunt goes in SERIES with the battery wiring. All of the current passing into and out of the battery passes through the shunt.  The shunt is actually just a low risistance, high power resistor.  When current passes through it, a small voltage will be present across it.  The amount of voltage will change, depending on the size of the load.  The battery monitor measures this voltage and keeps track of it over time.  Using ohms law, the amount of current in and current out can be calculated, and the approximate battery state of charge can be determined.

You should check the instructions that come with the shunt and the battery monitor for exact mounting instructions and precautions.

Hope this helps.

John
 

Steve,

Travis has the right idea.  The box keeps all of the wires safely enclosed and out of sight.  On the other hand, I try to get by as cheap as possible.  I poked around in the electrical section of my local hardware store and found bus bars for about $5.00 each.  Each bar allows about 15 heavy guage wires to be attached to it via large set screws.  I mounted each of the bars on a piece of plexiglass (for insulation).

Important:  Use the heaviest guage wire you can from the bus bar to the inverter, and keep THOSE wires as short as possible.  Those wires will be passing the heaviest current.

To answer your other questions:  You'll just have to use heavy guage wire, and keep each one as short as possible. I believe copper would be best.  The bus-bar arangement limits the number of connection points, so that helps.  I bought some large copper crimp lugs from Wal-Mart and soldered the wire to them instead of crimping. 

John

Steve,

As I said, and as the article confirms, connecting all batteries to common bus-bars is your best option.  You're going to have some resistance no matter what you do, but at least with the bus-bar method you'll have balance, and few interconnections between each battery and the inverter. The fewer the interconnections, the less resistance.

You can use a good quality digital voltmeter to check for problems at every connection point.  Check each connection point while the inverter is heavily loaded. 

John