Thomas Anderson's posts

FYI, I eventually found a phone number for Ivan Labs and had a back and forth with them.  Ultimately, they ended up repairing all the heads for me for around $200 total (they were out of warranty).  Apparently part of the electronics were damaged by a power surge at some point.  Also, it turns out I didn't actually receive the battery version of the heads from the vendor, but a much smaller tolerance DC power supply version, and I didn't always provide such a tight tolerance (they could have been damaged by equalizing my batteries).  Also, my home was struck by lightning a few years back, which may have been the origin of the issues.  Now I'm on a constant output DC-DC converter with fuses and breakers, so I hope to prevent the problem in the future.  So far, they've been running right through the winter and perform perfectly after being repaired.

This wiring diagram illustrates the basic configuration of any off-grid energy system.  You would merely scale it up to residential-sized components.  E.g. 1000Ah in several parallel 24V deep-cycle battery banks,  2x 80A MPPT charge controllers, a hefty multi-way battery switch, breaker panel, lightning protection, 3600W inverter (2 if you want 240VAC), etc....


BTW, the QO line of breakers and panels from Square-D are rated for both AC and DC.  I would recommend installing either 2 or 3 in your cabin -- one for AC from your inverter, one for 12VDC, and optionally one for 24VDC (e.g. for larger loads such as a well-pump, refrigeration compressor, etc.).

Definitely go for it.  There's really not much to it.  As an electrical engineer, things like proper safety, sizing cables, etc., really should be a no-brainer.  I second the advice to use DC circuits where appropriate, as it will save lots of energy and eliminate the inverter as a point of failure for those applications.  E.g. well pump, refrigeration, lighting, battery-powered device charging, etc.  Use AC only for those applications where DC is not viable, such as certain appliances, electronics, and automation-controlled lighting.  I have a power point presentation up at http://AndersonAlternative.com illustrating many different off-grid methods I've used in my home.

I highly recommend inserting an on-demand hot water heater in-line with your solar.  Let solar charge your tank as efficiently as possible, then when it goes to your fixtures, the on-demand unit will check to see if it's hot enough, and if not, add more heat.  I have mine set to 167 degrees to kill all pathogens.  Before the fixtures, I have a mixing valve to bring all faucets down to 120.  I leave my dishwasher and pot-filler at full temp though.  By setting the on-demand temp relatively high and putting it on a mixing valve, you only need a very small unit -- just a one-bath rated one -- because you only need a little bit of 167-degree water to produce quite a bit more 120-degree water after the mixing valve.  Just make sure to buy a unit that can achieve high temperatures.  I'm using the Takagi TK-Jr, and it works beautifully.

Depends on your inverter.  If it has a GFCI on the AC out, then grounding it in your house elsewhere will cause the GFCI to trip.  If it does not have a GFCI, then it shouldn't cause any harm.  That said, common advice is that you should only ground your system in one place.  Not sure if there's a good reason, or just rule of thumb.

No prob.  Glad to help.  Good luck.  I look forward to some photos.

Sorry about the image blocking on my server... you should be able to see it now.

I'm a little confused about your battery wiring. What you want is two parallel banks of two 12V batteries in series (for 24V); I'm not sure that's what you've got here in the diagram.

Make sure you use sufficiently sized cables for your batteries (triple-aught, I think) in the series connections. I would recommend a battery switch on the positive leads to each bank so that you can disable one for maintenance while still having power from the other one. Also a fuse on the positive leads. You'll have to check the rated amperage of your motors and maximum draw of your batteries to determine the appropriate size fuse. Probably around 200A.

I don't like the 4x AC charger when you're using a parallel/series layout -- I would use a 1x charger and run it to your battery switch. The AC charge controller should also be appropriately sized for your batteries. If you have these four batteries in parallel banks of series batteries setup, then you'll have 490Ah @ 24VDC. Somewhere between 5% and 20% of your batteries' rated amp-hours will both charge in a reasonable amount of time and also prevent overheating. So for your 490Ah, you want a DC output of between 24.5A and 98A @24VDC.

If the charge controller can handle it, you should put your solar panels in series for greater voltage (less loss) between your panels and your charge controller. If the panels are 12V, then in series they'd be 24V. If they are 24V, then in series they'd be 48V. The higher the voltage, the less loss you will have over the same sized wire.

If you have the room and the cash, I would scale up the PV panels and charge controller. 100W isn't going to do much to charge your batteries. I would think about 2x 200W panels and an Outback Flexmax 60.  That charge controller will be robust, provide system status, enable equalization of batteries, and provide plenty of room for future expansion if desired.

The Samlex is a good choice for DC-DC converter. I've been using a SDC-60 on my house and it works great. BTW, the 30A rating is on the output, so 30A x 12V is 360W. That's not a huge amount of power. If you need more than 360W, consider upgrading to the SDC-60.

Here's my recommended setup:

BTW, in this configuration, you can actually shut off both battery banks entirely and still power your DC loads from the IOTA, which acts as a DC power source in addition to a charger, while on shore power.  However, you would be limited to the 40A output (80A @12VDC -- more than the SDC-60 can put out anyway).  That said, it would be best to have batteries connected whenever possible.

One more consideration... if your motors use approximately 100A (2400W), then you'll have just over 2 hours of run time before the batteries are discharged 50%, which is about as far as you want to take them.  In an emergency, you could of course get more, but you might damage or shorten the life of your batteries.  Putting an automatic cutoff or at least a low-voltage alarm in the system would be a good idea.  If you need more run-time than that, consider adding a third bank of 2 batteries or increase the size of these four batteries.

I've looked at your perpetual motion machine and I'm afraid it fails....

Assuming this is true:
From stage 1 to 2 = it generates 2 kW

Then this is not:
From stage 2 to 3 = it generates 2 kW and consumes 1 kW

If the conversion of potential energy (unequalized water columns) to kinetic energy produced 2kW, then the conversion of kinetic energy (pump) to potential energy in order to re-create the unequalized water columns will be 2kW + entropy.  In other words:

From stage 2 to 3 = it generates 0 kW and consumes >2 kW.

Or if indeed you don't disengage your generators while pumping, then:

From stage 2 to 3 = it generates 2 kW and consumes >4 kW

The 3-4 and 4-5 stages merely repeat this fact.

So on total, your machine will consume energy equal to entropy, i.e. the energy lost to heat in the water pump and generators.  It will not produce anything net of what was put in.

Sorry.

How does this wave generator compare to a simple Faraday principle contraption of a magnet bobbing up and down through a coil of wire?  E.g. how one of those shaker flashlights work.  Compressing a spring to turn a wheel to turn a coil of wire seems less efficient than simply bobbing the magnet (or coil) up and down on the waves.

My recommendations:

1) Don't mount your turbines to your structure.  Use a separate pole mount.  Also, rather than three small turbines (lots of moving parts) mounted low to the ground (much less wind), consider a larger turbine mounted on a taller tower.  I'm fond of my Bergey XL.1.

2) Choose a high-quality, long-lasting (and warrantied), deep-cycle battery bank.  I like Rolls-Surrette.  Also, opt for independently switched parallel banks in case you need to replace one or more batteries or perform maintenance.  This way you can keep power flowing to your house while one bank is offline.  This adds redundancy and reliability.  If you only want to buy one bank for now, pre-wire it to add a second or third in parallel later.

3) Run extra wires between your shed and your house now rather than trying to feed extra ones later.  E.g. you may want to run CAT-6 wire to send system data to a computer in the house.  Or coax for security camera feeds.  Or you may want to have an independent inverter for your well pump or other large load.  You may also want to (and I HIGHLY recommend to) run some DC loads in your house directly.  Pull all of these wires at the same time even if you don't use some of them yet.

4) Put lightning protection on your indoor breaker panels, because lightning can strike the ground between your shed and your house and overload your house circuits.  Also make sure to have a surge protector on your inverters.  Over-amperage protection (breakers) is not enough.

5) Don't put off the backup generator but don't go overboard on it either.  You don't need to run your whole house with it, just charge your battery bank.  A camping-sized propane generator ought to be sufficient.  Mine puts out just over 1kW, which is as much as my wind turbine is rated at top speed.  That's plenty to charge up the batteries.  The batteries themselves handle surge loads.  I.e. you may be running your 1kW generator to charge your batteries for an hour, and during that time, your well pump may pull 2kW for 3 minutes.  No problem.  You don't need a 2kW generator for that.

6) Opt for propane rather than diesel or gasoline for your generator.  Propane does not need stabilizers to keep for a long time, it cannot spill on the ground, and it doesn't gum up engines that may not run for 6-12 months between uses. 

7) Make sure to vent your battery boxes to the outside, store extra distilled water at all times (unless using AGM or gel batteries), and install freeze protection inside.  While charged batteries can go below freezing and be OK, they won't hold their charge as long and won't charge up as fully.  It's actually more efficient to leave a 20-40 watt light bulb on in there than to let the batteries freeze.  You'll have more usable power that way.  I have two CFL light bulbs (about 20W each) on a little thermostat cube which turns them on below 40.  My space is only about 5'x5' though -- you may need more heat than that unless focused near your batteries.  I would avoid heat tape or space heaters because of the hydrogen.

8 ) If using regular flooded batteries, buy water miser caps to reduce the number of times you need to top them up.

9) Make sure to size all of your wires big enough and use fuses where appropriate.

10) Be safe at all times.  Make sure someone knows you're working on electric before you start so they can check up on you.

Assuming firstly that you have no electric resistance heat loads such as electric furnace, electric clothes dryer, or electric stove (which would make the project unfeasible), the largest consumers of electricity will be first a well pump, secondly a septic pump, and thirdly any compressors -- refrigerator, freezer, air conditioner.  If you're on city water and sewer, you can eliminate the first two.  That makes your choice of (EnergyStar or DC) refrigeration appliances extremely important in your calculations of load.  Most other loads are fairly negligible assuming you use LCD televisions and LED light bulbs versus the energy hog alternatives.

You also have to consider peak usage -- what if all four apartments decide to use a hair dryer, or toaster, or vacuum at the same time?  You need to size your battery bank, cables, and inverters to handle that peak load even if the average load is much, much lower.

Also, is someone going to be monitoring this system or is it just supposed to work no matter what?  If someone will be keeping an eye on it, then you can plan to accommodate average input conditions and start a backup generator (perhaps automatically) if the batteries get too low.  But someone has to make sure it stays fueled, unless perhaps you have a city gas hookup or a large propane tank with regular deliveries.  If this is not the case, then you would have to oversize the system to account for low energy input (a string of overcast days if using solar, a string of calm days if using wind).

Also, will all loads be running off an inverter or will you have some DC loads as well?  Remember that conversion takes 5-10% right off the top and certain loads such as compressors or motors may be significantly less efficient on AC (power factor) than DC.

Also, are the people living in these apartments expected to follow certain guidelines, such as don't use a hairdryer or only do your laundry during the middle of the day?  Also, no super-powered gaming computers or window air conditioners.

There are a lot of considerations.  One size does not fit all.  That said, if you just want to over-kill it, go with 4kW of solar per apartment and 1500Ah of battery capacity per apartment (still no electric resistance heat loads or other huge loads!).  That will be significantly more expensive than it likely needs to be though if some of the considerations mentioned above favor efficiency and flexibility.  The low side would probably be around 1.5kW of solar per apartment and 600Ah of battery capacity per apartment.  That's a range I would feel comfortable settling somewhere in between.

You can't power a generator by a motor and expect to get out more energy than you put in.  It was probably a diesel generator.

Every kind of energy source has its strengths and its weaknesses.  No one technology is the magic bullet for society as a whole or even an individual location. 

I'm happy with my Bergey XL.1 turbine, but it would be fairly useless to me if not paired with solar and a good battery bank and a backup propane generator.  I have a good location 500' up on a hill, but wind is not consistent.  It tends to blow more in the winter than the summer, and more in the evening than mid-day.  This happens to perfectly complement when solar is most useful.

You also can't design a system to supply the absolute maximum energy you will ever need because the system will be overkill for 99% of the time and probably too expensive to even set up in the first place.  So for those 1% of times when it's calm and overcast or you have a huge party or house guests, a backup system needs to be in place that is relatively cheap and capable of sufficiently boosting energy production.  A propane or diesel powered generator is a good option.  I use mine perhaps twice a year.

Also, if you're going to primarily rely on renewable energy sources like wind and solar, the first thing you need to do is significantly reduce your expected energy consumption versus typical American usage.  To power an average house would require a renewable energy system more expensive than the house itself!  The only way it becomes affordable is to maximize efficiency.

Once you've accepted and considered all of those things, then wind is a viable energy source and I would recommend it for those who have a suitable location.

You can message me here or email me: altestore {at} andersonalternative.com

I'm not convinced that's true.  Why would a discharged battery receiving current from larger batteries ruin it?  Seems to me that it would tend to keep it charged.  Imagine a big tank of water pouring into a 5-gallon bucket pouring into a glass which pours into your mouth.  The glass has very small capacity but is being constantly refilled by the bucket.  The bucket likewise has smaller capacity than the tank, but is also being refilled as quickly as it is discharged.  If anything, the largest capacity battery would have the most volatility in charge level with the smaller ones only discharging very much when the biggest has drawn down significantly.  This of course is all conjecture and should actually be tested.  I would recommend trying the setup for a few full charge/discharge cycles and measure the level of each battery throughout the process.  If you graph the three batteries % of full charge throughout the cycle, I suspect that the largest capacity battery will show the biggest swings.  I'd be very interested in seeing the result of this mission, if you choose to accept it.

Do you have a website?

14 for regular charge, 15 for equalizing.  11 is about the bare minimum to discharge before causing damage.  So anywhere between 11+ and 13+ is the usual range to find it in.

Sounds great!  I just assumed that radiator fans were belt-driven.  I had no idea they used a 12v motor.  I may look into that for my whole house fan.  In my setup, I'll be pulling in fresh cool air through earth tubes.

You could add a diversion load to your system.  This only activates when your batteries are full and more power is still coming in.  Usually diversion loads are heat sources such as a hot water heating element, but you could also potentially attach an air conditioner in the summer, a water pump e.g. to pressurize your house water or to water plants in your garden, etc.

Personally, I would add more batteries in parallel first, and then think about a diversion load after you have sufficient AH to power your house for a few days.

You say comparable to new, but batteries have a rated number of charge/discharge cycles, so they ought to be pro-rated according to just how "used" they are, which ought to be transparent.

Your geographical location prevents you from getting small packages shipped from a web-based merchant?

I don't know anything about the Sunsaver Duo, but so long as they do not share a common negative between the two sides, then it should be possible to charge each individual battery while they are also connected in series.�  But I can't stress this enough... the two sides must be isolated, otherwise there will be a voltage across the shared part and it will probably blow out your charger.�  I did this for a short time -- I have 6 4v batteries in a 24v bank, and I used a dual 12v charger on each half.�  It worked OK, but I upgraded to a 24v charger when I had the chance.

I'm not sure the 12-48v DC-DC converter suggested will be useful since the amps delivered will be paltry.�  Although a 92AH battery bank is pretty small, you want to push at least 10A to it.�  Most likely, your Sunsaver only puts out 10A @12VDC on each side, which is only 2.5A @ 48VDC.�  If you sent this @12VDC to each battery individually, it would be sufficient, but just one leg of one charger to the whole bank @48VDC wouldn't cut it.� 

Your best bet is a 48v capable charge controller such as the Outback Flexmax 60: http://www.altestore.com/store/Charge-Controllers/Solar-Charge-Controllers/MPPT-Solar-Charge-Controllers/Outback-Solar-Charge-Controllers-MPPT/Outback-Flexmax-60-Solar-Charge-Controller/p6875/

Then you can connect your panels in series and your batteries in series and connect the leads of each to your charge controller and it'll just work.

Wow that sounds really unsafe.

I agree and should have mentioned the need for ventilation. But that doesn't mean it needs to be exposed to the elements.  Hydrogen is the lightest element, so as long as it has a path to escape at the top, you can keep the enclosure otherwise pretty tight.  I have a 1.5" PVC pipe from the top of my boxes leading out my shed roof.

Another consideration, if you're building your box on the outside of your shed, is to put it on the south side so that it can collect some solar heat during the day.  And if it gets snowed in, that's actually not a bad thing, because batteries are fine at 32F as long as they have a charge, and snow is a great insulator.

I disagree with Tom Mayrand about the need to keep the banks separate and I agree with your intuition.  If they are connected with sufficiently sized cables (triple aught for 24V), whichever bank needs more charge will get it, like two pools connected by a canal rather than a garden hose.  However, there are limitations based on system voltage.  At 12V, I'm not sure you could get cables thick enough to make it work.  You need to determine the maximum amps you expect (and I would leave room for system expansion later -- it usually happens) and calculate the size of cables you need.

Here's some more info on 12V vs 24V:
http://www.rpc.com.au/products/efn/efnextracts/12v_or24v.html

I would recommend wiring the batteries at 24V instead of 12V for a variety of reasons (you can Google for plenty of explanations about benefits/drawbacks of battery bank voltage).  You can do that by putting 2 12V batteries in series or 4 6V batteries in series, and paralleling them.  You will definitely want a charge controller to apply the appropriate charge to the batteries.

I don't think mixing different kinds of batteries in parallel at the same voltage is so terrible an idea as is commonly believed.  It may be that the weakest ones are cycled the most and need replacing before the other ones, but they'll be better off and longer lived than if used on their own without being paralleled with stronger batteries.

As far as managing how the loads draw power... just wire all of your loads to the batteries.  If your solar/wind are producing, the loads will essentially skip over the batteries as if they're just a wire, and draw from the output of your charge controller.  If your charge controller isn't putting out enough, the loads will draw down the batteries to make up the difference.  There isn't any special logical device required to do this, it's just how electricity behaves.

Regarding freezing protection for your batteries, I would recommend putting them in a very well insulated enclosure and installing a thermostat-controlled heat source inside such as heat tape (connected to a heat sink for safety) or a lightbulb.  My Pennsylvania winters don't get as cold as yours, but we do have long nights which reach below zero Fahrenheit. I have my batteries in a very well insulated shed and I have a 100W-eq compact fluorscent lightbulb which turns on when the temp gets below 34F.  Because it's well-insulated in there, this is sufficient to keep the temperature from getting much below freezing.  I think the actual draw of the lightbulb is around 25W, so even if it stays on 24 hours, it's only 600 watt-hours per day.  If you had only two hours of sunlight, two 150W solar panels tilted toward the southern horizon could supply that amount of power.  It seems counterintuitive to save your batteries by drawing them down with a load, but in this case, the load draws less than the cold would.

BTW, I also think a wind turbine is a good idea, and a 1kW model would provide plenty of power to keep your batteries warm if coupled with a small heat source as described above.  It shouldn't cost more than about $10k installed.  I own a Bergey XL.1, and it works great.

By DIY, do you mean you built it yourself, or you installed it yourself? 

Some commercial units come with charge controllers which have voltage compensation, i.e they step up the voltage from what is actually produced in order to make it productive in lower wind speeds.  My Bergey XL.1 does this.  When the wind speed is low, the green LED blinks, indicating voltage compensation.  When the wind is strong enough, the green LED is solid, indicating sufficient voltage.  So in that case, if you wanted to check the output voltage, you'd have to know whether you want the raw output voltage or the battery charging voltage.

Since you mention a diode, I assume that this is a home-built turbine and the diode is used to convert AC from the stator to direct current for battery charging.  In that case, then if you want the raw pre-diode voltage, you need to use an AC voltmeter.  To measure the battery charging DC output, then you would use a DC voltmeter on the battery side of the diode.  BTW, a bridge rectifier would be better than a diode for converting to DC.  With a diode, you only capture half of the power (the positive half of the AC wave), whereas a rectifier captures the full output.

Me too, exactly the same situation.  Pay the same amount up front, but don't pay an electric bill ever after.

It's hard to take seriously any calculator which gives estimates decades away which doesn't factor in inflation.  In reality, payback (on a purely monetary basis) is much sooner.  At only 2% inflation, prices double in 36 years.  At 10% inflation, prices double in 7 years.  A truly accurate calculator must do compounding for inflation.  E.g. see my light bulb cost comparison calculator.  It makes a huge difference.  One of the greatest advantages of going off-grid or even just installing supplemental solar is that your costs are defined, which removes a lot of risk, which is extremely (though non-quantifiably) valuable in and of itself.  So a great calculator would allow you to put in a range for average annual inflation and provide a range of payback periods which may be decades apart depending on inflation.

Alternatively, can't you just put the wires in a conduit?

Ah, yes, that makes sense.  34V would be correct at maximum insolation.  I wonder how often you could expect it though.  My panels routinely put out only 80% or so of their rated power in full sun (1.2kW out of 1.5kW rated).  When they say "maximum" they really mean "maximum" as in an extreme outlier.

1) Grid-tie inverters interface with a grid connection to receive and sell back power, using the grid like a battery bank, and will shut off the flow of electricity if the grid power goes down in order to protect electric company linemen.  Generally, these do not also use or charge batteries.  If you want both grid-tie and battery usage, you need a grid-capable off-grid inverter.  A purely off-grid inverter does not have the ability to interface with a grid connection and does not contain any of the safety features to allow safe connection.  Off-grid inverters only work with batteries, or without batteries they will only function so long as your power sources are producing enough voltage.

2) The size of the inverter will be dependent on the size of your loads.  Obviously you cannot use a 500W inverter to power 2000W of loads.  Generally inverters are rated for continuous and instantaneous loads.  This means they can start a motor which draws a high amount of power initially, but runs on a lower amount.

3) Lightning protection (sacrificial), over-voltage (surge) protection, and over-amperage (breaker/fuse) protection are recommended on both the supply and load sides.