Author Topic: Best Off Grid Set Up?  (Read 6791 times)

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Re: Best Off Grid Set Up?
« Reply #30 on: April 14, 2017, 12:32:17 PM »

 Got a question, George. I have heard some guys speak of ring coking. Is this a problem with WVO and, if it were to happen, how would one alleviate the problem, sans a tear down and good cleaning, rebuild?

Ring coking is the perpetuated and grossly overblown fear of the Veg/ waste oil world.

People crap on about it chapter and verse but the actual instances of it happening are far and few between and then even those are repeated.
As I pointed out on a forum nay years ago, tell me if you have first hand actual knowledge of an engine suffering ring Coking. Not your mates coworkers brother inlaws uncles panel beater, But you yourself or a mate you know well.
In a forum of several hundred people logging on a day ( this was back when veg was all the rage) the only person that had seen it was me.  I helped a friend pull the old clapped out engine from his merc wagon and the thing hadn't even got to run on oil yet.  It was just it was buggered and as well known, they will coke up on diesel as the last stage of their demise.
I then did a quick count of the posts about ring coking that month and found about 12 separate threads of worry and concern on it and about 100 grim and dire warnings if you didn't follow the prescribed, socially approved parroted mantra. 

Yeah it happens, no question but for every case it dose there are probably about 10000 worry wart posts and fears about it.  I have only seen or heard it happen because of other pre existing problems.
Case closed from my POV.

Let me just put my future statements in perspective and where I'm coming from with them because they disagree with about 95% of the approved and parroted Veg oil mantra.
My first veg car was an old merc I didn't actually want to buy but my wife talked me into that particular car. I wanted a merc but this one was not in good shape so I didn't want THAT merc.  Didn't get it 10 KM from the seller and it broke down and had to be brought home on a trailer.
In hindsight, best think that could have happened.  I learnt so much on that old thing and I would blow my own trumpet as saying I am up there with the most knowledgeable people in the world on veg.  Egotistical, of course, but there is a real good reason I say that.

Most people try NOT to break their car.
 I was the complete opposite.
 I didn't think the thing would last till the rego ran out and therefore I was interested to see what would kill it.  I tried all the fabled fears and problems and found about 95% of them are pure and utter bunk. The rest are so unlikely not to matter or can only come about through neglect or stupidity.
And thats the other thing right there. I TESTED these ideas. Unlike pretty much everyone else, I didn't just copy the guy before who copied the guy before him who lived in another part of the world who did what the guy before him did etc and no one ever thinking WHY they were doing something, IF they needed to do it or what their particular situation was.

I got my hands dirty and when someone said this will kill your engine, I ran out and tried it instead of avoiding it. I researched things not just only in the veg world but looked at other industries and applications and what they did. In that alone I found endless bunk and misinformation that other people and industries defie every single day. Not in using veg oil per se but in the theories and practices veg oilers held.
One of those things was was preheating the Oil ( fuel) where people would use 2 or even 3 30 plate or larger heat exchangers.  From working with a mate on pool heating, I knew by the look of the things they had to be waaay overkill on one let alone multiple.  I looked up the data sheets and got a sales rep to crunch the numbers as far as fuel flow, specific heat density of oil and water, etc and the rated output of the HE itself.  I found the things were about 50X overkill for the fuel volume required and it was a joke using one 30 plate when  5 plate would do let alone using 2x 30 plates.
There are endless things like that people do without thought or question because that's what they are told and they never question if THEY need to do it or why anyone does it in teh first place or what problem they are trying to solve or over come. They follow blindly and that's it.... till their over complicated setups fail and then they try to complicate them more to offset the wrong problem.

Turned out I got to love that car, fixed it up and it was a part of our family like a loved pet. I called it Helga and people would ask me how he  wife, kids and Helga were when I saw them. Had it for 3.l5 years till, like Bruces example, I went to pull the thing off the road to give it a complete restoration and wasn't an hour into it before I found so much structual rust restoration would be completely impractical. Pulled the engine which I still have and sold it to an arab guy who put it in a container and sent it back to the middle east to be used as a Taxi.  Told him about the rust which he said he would fix but I strongly suspect that "fix" would involve nothing more than kilos of plastic putty and maybe some under body sealer.... or just spray paint. 

From that hands on testing experience and knowledge I hold myself out as having more hands on, real world, tested and Documented experience than all but a very few people out there. I have proven over and over that so much of the common veg practice is not only unnecessary but the reason behind so many ideas and practices does not add up with physics or logic.
So, coming from that self centred attitude, heres my thoughts and more so experiences.... :0)

The whole pre heating the oil thing with oil is a real big parroted fear amoungst most oilers.  It also for the most part is complete and utter bunk.
If you look at the two most suitable types of IP to use with Veg, the inline and rotary style pumps ( or plunger type on small engines) and look up their viscosity tolerance as set by the manufacturers, it covers  pretty much any oil you could reasonably pump down a fuel line. The inline pumps like on mercs will pump lightly gelled liquid fats with no problem.  Warming the oil to thin it so the IP can handle it and the injectors can spray it properly does not add up. It's that simple. The greatest reduction in oil viscosity is from 0-40oC from 40-80 as most people prescribe, the reduction is only a few centistrokes or a fraction of the 0-40 reduction.  Also pressure does NOT affect injector spray pattern. With conventional injectors, the pressure must be reached before they pop off, if it's not they won't pop and the engine won't run.  Therefore viscosity of the oil as long as the IP can handle it, which it can if the oil is liquid, is irrelevant.

And that's when the engine is cold.  Soon as it heats up, the injector which is embedded in the hottest part of the engine, the head, has a huge amount of heat transfer from the head and being exposed to the combustion chamber. To assume that  the milliliters of oil that pass though an injector in a minute ( had the numbers once but forgot now but very small) would be sufficient to cool that injector or indeed have much effect on its temp at all does just not add up or gel with principals of thermo dynamics. It makes ZERO difference to the spray pattern because the injector must exceede its pre set pressure to pop off and if it does, the spray pattern is the same.

The REAL cause of  ring coking I believe is something no one ever realises.
I believe ( and have demonstrated) it is almost entirely ( in a healthy engine) dependent on the Injector pump fueling setting and to a lesser degree, pump timing. 

If you get a tablespoon of Diesel, kero, petrol, biodiesel , turps etc and put it over a blow lamp till it all burns away you are left with nothing. Do the same with oil, veg/ engine, tranny fluid etc, you get a deposit.  Mostly that takes multiple stages. At first it burns to a sticky tar. Keep the heat up and it turns to carbon like charcoal and then it turns to ash like wood ash. You can easy do this test yourself like I have to see.

If the engine is fueled so there is enough air to burn all the oil, I can only assume the oil is burnt to ash and exhausted.  If it is below that, then it is likely to remain, in part at least, in the cylinder and will be scraped from the walls and end up in the ring lands.  Because this is a cooler area in the piston and often has holes behind where oil may be admitted through the rings to the cylinder, the tar and carbon build up. there is very little area for the flame front to burn these deposits off like they could on the piston crown, valve faces etc.

When a diesel engine smokes under load on Diesel, the carbon is just blown out because diesel burns clean.  When a diesel Smokes on oil, it's most likley leaving deposits.  That's OK unless those deposits are excessive or there is something else at play like too much oil coming in the form of EGR bypass, bad rings, worn valve guides etc but I'll assume an engine in good condition for the sake of yet another long winded post.

Now if the smoking of the exhaust is short lived like just under heavy acceleration and the fueling of the engine is set at factory levels, for the most part one would be fine. May be different if you do a lot of hill climbing at full throttle  etc but for regular driving, I believe these deposits are light enough to be burned away over the much greater period the engine is running lean with excess air as diesels usually do cruising along.
If one turns the Fuel right up like I have on my Turbo Diesel Peugeot I had so the thing will spin the tyres  in first gear rolling along with the clutch fully out, then the smoking is much heavier and longer lasting meaning the engine is getting a lot of buildup.  If you touch the throttle and the thing starts smoking, you are in for a short engine life... unless you offset the problem.

If the timing of the pump as become out, particularly late, this is also detrimental to coking.  Ideally you should set the pump about 5o sooner than normal because oils burn slower than diesel and therefore need more time in the cycle to light off and reach peak Cylinder pressure. Late timing means the charge does not have enough time to burn and the fire well may go out before the combustion is complete which results in the tar deposits.

Again, on a normally tuned IP under normal driving conditions, IE no unusually long periods of wide open throttle, I'd say the chances of ring coking on veg or WMO are the least of your worries and behind getting taken out by a drunk driver.  Just NOT going to happen.

But what if it does? What if like me you turn the wick up too far or you DO tow up a mountain every day?
There are a whole load of fuel additives and cleaners you can use.  And you will waste your money on each and every one of them. Physics and understanding of how engines work will tell you, they can't.  There is nothing out there that is actually designed for this problem.  Might say it is but they sure as hell never had veg oil in mind! :0)

There is a solution. Its cheap, simple, easy and that's probably why most people won't take it seriously. I have noticed, and sorry to all it offends, Americans particularly have this disposition that unless something is expensive, complicated, has loads of parts and therefore failure points and big numbers, it can't possibly work.
Well in this case it absolutely does.


And Im not talking some $600-1200 commercial system here that sprays the water to a fog finer than found in a rain cloud, I'm talking something that just kinda sprays the dam water in to the inlet and that's it.  The airflow and heat in the cylinders will do the rest. I believe in fact that rather than having the water vaporise before it gets in the cylinders, for the purpose of cleaning its far better to have the water enter in droplets.
I researched this when people told me that the phase change from a liquid to a gas caused tiny explosions called cavitation.  I knew of that in marine terms but I looked it up and that's what happens.  In a cylinder the pressure raises the boiling point of the water droplets until it reaches a critical level where it actually explodes to vapor.  Now these micro explosions are not significant enough to cause erosion of ANY metal let alone the alloys of aluminum used in pistons or the heads or steel more commonly used in diesel engines.

It is, wonderfully, conveniently strong enough to remove carbon or tar deposits which is what we are dealing with.
Basically the water steam cleans your engine by blasting off the deposits and because it is so fine and not burnt like many believe, it can permeate all parts of the Cylinder including the ring lands.
You can set up a WI system to run heavy for cleaning and then when the engine is clean, and you will be in no doubt when that happens, you can back the water off.  You don't have to, you can run the water heavy all the time. just means you'll be filling your tank more, a LOT more. 

In the case of the Pug, I ran the water at a rate of 300Ml a minute which is my almost universal dose rate.  This was a 2L engine and I ran it pre turbo... which I would not do or recommend but I was still learning and that is what I did. I believe it took the edge off the tips of the compressor blade and made the turbo develop less boost at lower RPM causing the boost to come in later.
 My WI setup at first was to use the windscreen washer pump and bottle to squirt through a Micro mist home irrigation nozzle. Mist is a relative term on these, they are a coarse spray in fact which is actually what we want.
 The pump was triggered through a Hobbs/ pressure switch set to activate at 3 pounds boost.
And that was it.  I filled the bottle daily and then went to a Diaphragm type pump I bought off ebay and a 5l oil container that I squeezed under the bonnet .  Still filled it every day pretty much but at least I got a lot more water through the engine.

If you want to clear a bunged up engine fast, set the thing running to about 2500 RPM and pour water straight down the intake.  take the turbo pipe off if you have to. It won't be boosting under no load anyway.  Pour the water in just fast enough so the revs don't drop or drop slightly.  If they start to fall off, ease up on the water. You'll be amazed how much you can pour in there. A liter a minute is easy.
DO NOT park the car with the arse end facing your wifes petunia patch, your garage door or a house wall, the freshly painted white Pickett fence or anything you don't want sprayed and dripping with a black sticky gunge. Shits gunna fly everywhere and it's near impossible to really get off.  Not just from the engine but from the crap buildup in teh exhaust which  I believe is something regular WI also cleans and keeps the gas flow up resulting in better performance.

I inject 300Ml a min on my 4.2 L engine as a normal dose rate. People that see the benifits of WI tend to get carried away with it and want to run water when ever the engine is running and pump the stuff though like no tomorrow.  That's a mistake and unnecessary. You only need enough to prevent any buildup and that takes weeks if not longer on an over fueled engine. It's not going to happen at all on a normal fuel rate so it is a preventative rather than an absolute need like engine oil in the sump.  I have my engine over fueled for performance and I also like the performance increase the water gives.
On my old merc, just plain water alone reduced the 0-60 KMH (0-35? MPH)  time by 3/4 of a second.  May not sound much but ask Bruce what a difference that is a non turbo merc.   Means it gets to 60K probably more than 100 m of roadway sooner.  With meth added to the water, the time taken from many runs over different times and conditions averaged at a fraction under 2 sec faster.  In that car, that is a HUGE boost in performance.
Remember, That was 60 KMH not MPH.  I couldn't find a quite straight road long enough anywhere near me to do the 0-100KMH (60 MPH test).
I asked a place that had a 4KM bit of road but international airport operators aren't very co operative when it comes to letting old shitboxes on their runways after kerfew I found  :0

On the current truck, the meth makes the thing too fast for it's brakes and handling really.  On a section of the highway I regularly travel up the steepest, longest hill around,  I purposefully slow as much as I can at the bottom and then floor it as It starts to climb in top gear. By the top I am well over the limit and have to back out of the throttle because the engine is still pulling but I'm starting to over rev and have no more gears left.  Thing pulls like a train and I have upset more than one driver of much newer and supposedly more powerful trucks. Still a slug on takeoff with it's weight but at highway roll on speeds, the thing eats hills for breakfast.

I found adding Methanol/ ethanol to the water at up to 50% not only gave a performance boost but also aided in the cleaning process. I have not come up with a reason as to why that is. Even when I am running the WI on my engines that I know are clean through constant use and with the ip turned well down, If I run some meth for the fun of the shove in the back it gives, the engine still has more pep even when the reserve is refilled with water and the tank is half or more used. I haven't been able to figure that one out yet. Eventually performance comes back to normal but it is better even after the meth is well gone. I can't see the the engine is extra clean to the point of better performance otherwise the engine would continue to decrease till it logically stopped. I wonder if it might have to do with the exhaust being clearer and allowing a better gas flow?  I have seen the phenomena 100 times, haven't come up with a reason I'm convinced of to explain it yet.

My current vehicle has a 25L water tank in the back and is fed buy the same Diaphragm type pump. I use no nozzle at all now, the water goes into the manifold through a compression fitting which holds the 1/4" copper pipe which is a little flattened on the end. That is it. No mega pressure pumps, no microfine spray, it goes into the manifold as a wide thin stream and that is it.  It'[s something I have trouble getting though to people. They won't belive there is no nozzle or spray jet or whatever.  The airstream breaks the water into fine droplets  as does hitting the manifold walls, the valves, pre chamber etc.

The current pump is dual triggered.  Firstly through a pressure switch which is set at 4 lbs of boost and a plate on the throttle stop which makes the throttle pedal itself act like a switch on the ground side of the circuit.
The reason for the pedal switch was firstly I devised it for my non turbo truck I couldn't use a boost signal from.
Secondly, when using  Meth in the WI, I can flatten the pedal and get the meth in the engine at any RPM or boost level which brings it on to boost quicker particularly for roll on acceleration without having to pull back a gear if the engine isn't at boost speed already. I have used that in winter to give a shot of meth into the engine for a cold start particularly if I was a bit shy on the glow plugs and am running straight oil with no added petrol . Makes the thing fire much easier.

The whole thing with the WI is it does NOT have to inject a fine mist like all the WI kit makers will rave on about. A fine mist has some benefits at cooling the inlet charge for performance purposes but I'd guarantee its more to do with big numbers, sounding more impressive than actually making a difference to the engine above a point way lower than they exceed.

On my stationary engines I just drip the water through a hypodermic needle as the metering device into the inlet port. The hypo is very convenient,  just to stick through the rubber or plastic flange of the filet mounting or the priming port that my china diesels all have.  My Internet mate in south africa that run his homestead and business from his Lister generated power also is using WI and stoked with the difference.  His hard worked engines running the thick sump gunk he gets needed frequent de coking and suffered  declining performance well before that.  A run on diesel would help but was obviously costly and the benefit short lived.  His Wi system is manually activated and just gives a heavy dose of water at the end of each run.  He uses enough water just so the engine does not stumble but will chuff out some water and chunks of carbon.  it seems to be keeping the engines running fine and when they do start to bog down sometimes during a 16 hour average run, he hits the WI again for a while and they come back up to full noise.
He has just rebuilt one of the engines after an insane amount of hours work on it and bumped the compression ratio and spent a lot of time fiddling with and checking the results of changing the pump timing.

I would not run an oil fueled diesel vehicle without WI myself.  Everyone I know that has tried it even if they are running bio has seen the difference it makes and run it from there on.
There are as many misnomers about WI as veg oil, one of them being that it will increase fuel economy and if you go too much on the water it ill hydro lock the piston and destroy the engine.
WI will NOT increase mileage. If it is properly set up it will in fact decrease it by an amount less than driving habits however it will be a decrease none the less.
As for Hydrolocking, another thing you'd have to put serious effort into getting it to happen. I have had a friend run 2L a minute through his 2L diesel and apart from blowing clouds of steam, had water running out the tail pipe and being undriveable, the thing was completely fine. Corrected his mistake with the water delivery and no more problems. the thing just continued to get better for a couple of months till it plateued out ovbviously clean and stayed at that improved level.

I have an old Toyota diesel engine and am thinking about doing something to run my portable sawmill. Diesel here is around $1.40/litre. Also thinking about wood gas. Got a lot of trees that will produce a lot of waste just from the tops, let alone the side slabs.

No experience with wood gas but done plenty of reading on it.
My Impression is it's a LOT of work and infinitely harder on your engine than liquid fuels. The learning curve also seems a lot steeper than with oil. Unless you scrub the gas very well and get all the ash out which I don't think you ever can, the engine will wear very quick. Something like a saw mill that does limited hours, might last 20 years so no problem.

The distinct Impression if get is that Oil is loads easier to use with instant startups and shutdowns and a lot  easier to run an engine on it.
If you can get oil I'd suggest it would be the far easier way to go, If you can't get it or enough, then use the resources you have and do whatever you need to setup and make use of them.  :0)

Harold in CR

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Re: Best Off Grid Set Up?
« Reply #31 on: April 14, 2017, 07:50:28 PM »

 George, thank you very much for that information. Down here, all the waste oil is burned by the farmers or truckers that can get it, since fuel costs are so high. Palm oil is a big cash crop, and used in fast food restaurants. I checked into it way back, but, not available, especially way out where I live. Local bar/cafes give it to pig farmers for mixing with the feed.

 The wood gas would be my best source, and, I can run the gas through a barrel of sawdust that will scrub the ash from the gas. Sawdust will be plentiful and, my buddy a half mile away has a commercial sawmill, so his dust will get me started. Sawdust is something I have thought about building a pellet mill, but, that takes energy to press the pellets.

 A clean out is necessary in the pipeline for catching some of the ash and tars from the wood. Of course, dry wood would be best, but, with rainy season 9 months of the year, little chance of that happening, without making a kiln of sorts, which uses wood to fuel it.

 Anyway, lots to think about and again, thank you.

 Harold in CR


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Re: Best Off Grid Set Up?
« Reply #32 on: April 16, 2017, 01:53:17 AM »

Didn't know you could use sawdust for a charcoal Burner.

My grandfather had one on his truck in WWII.  Heard so many times from the family how his trucking company had a good Government contract because the trucks could go from the important country town where they lived to the city on just a Pint of  Petrol. 
There is a guy on another DIY power forum I frequent that instead of going the Diesel route has gone with woodgas for his fuel needs.

Came up to the country today to Visit my father. as it's been raining, we lit up a pile of rubbish. Got rid of a LOT of old engine oil on it and I was surprised how little smoke there was from it.  Hell fire heat though.
Enough old wood in the bonfire to probably get a charcoal burner a good distance as well.

I remember many years ago there was a guy here that Drove round Australia with his wood burner.  From memory he went through 3 engines in the process but he didn't use a drop of Petrol!  :0)

Harold in CR

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Re: Best Off Grid Set Up?
« Reply #33 on: April 16, 2017, 07:34:04 AM »

 Problem with wood gas, just as you say with WVO, it's all about how it's done. A properly built woodgas burner would have the gas cooled down before entering the traps/filters. The one I might copy, shows the maker holding the gas delivery pipe bare handed, before it gets to the sawdust filter. He has a glass jar to catch the tars and can simply unscrew it to clean it.

 I have the original 20 HP Honda V-twin from the sawmill. I have cleaned the carb, along with wife's son (excellent mechanic) MY son, another pretty good mechanic all around smart guy, and the engine will only idle IF it manages to fire up and run at all. Takes a special "pulse fed" carb, and they go for over $200.00 + USD. Then, I get the privilege of buying $6.00 + gallon of gasoline.

 I would love to find some unpolished SS milk line tube to build mine, along with a SS barrel and a SS beer keg for the filter. In the states, I can find that stuff easily, just shipping eats the shorts.

 Damn, we are really jacking the OP's thread now.  ::)

Mary B

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Re: Best Off Grid Set Up?
« Reply #34 on: April 16, 2017, 02:14:24 PM »
For stainless kegs maybe check for these in your country. Formerly used to hold coke or pepsi syrup products that was then mixed with carbonated water. Beer brewers now use them as beer kegs. This is my new beer fridge I am setting up. They are called Cornelius kegs, pin lock kegs, ball lock kegs and can be found on Craigslist, ebay, and online sources. I paid $35 each for these with disconnects and new O ring sets.

Harold in CR

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Re: Best Off Grid Set Up?
« Reply #35 on: April 16, 2017, 05:18:06 PM »

 Thanks Mary, but, down here, any metal found goes directly to the scrap dealers. It's nearly impossible to find scrap metal for projects. I have asked around for anything for scrap, but, none available. There are small pickups running up and down the roads looking for metal, even the 30 ga. old rotten corrugated roofing they pick up.


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Re: Best Off Grid Set Up?
« Reply #36 on: April 17, 2017, 02:10:45 AM »
Hi FoggyNotion, again.

Back onto topic ..... I will have a stab at it........

Off Grid is always going to be difficult to fully understand, as there are so many variable's with your own particular situation.

However, the World is changing, and folk see generating and using their own created power as a big step forward, and forums like here, independent folk/organizations like ours, are slowly spreading the Word .

Economically /cost effectively batteries are a problem, I and many others stick to tried and tested lead acid.
Our philosophy here at 'Echorenovate' in Normandy, France, ........ Keep it Simple, Make it Robust, and Keep it Cost Effective.

Novemeber 2016 The below, from 'Oztules', Flinders Island, Australia, is a very good , uptodate, synopsis of the state of Renewable Energy for the normal Domestic Household.

My apologies if I have posted this here before? .....

Totally Off Grid With Solar. ?

There are a few installations down here now that came in around the $15000 dollar mark.

They use 10kw of solar, home brew inverter, home brew solar controller, and 35kwh battery banks.

They have no other form of power except they do have generator change over if necessary.

So far that has never been required but for one exception... out on one of the islands parks and wildlife had a rat eradication team over in the worst sort of solar weeks we have ever seen 10 days of heavy rain... and 15 people... this was a bit much, and the genny ( 5hp with modified car alternator) ran for a day..... thats it... power was rationed after that as the 15 city folk had no idea of conservation, and left the shearing shed lights on all night (600w for 14 hrs before the sun comes up), 15 ;lots of phones and ipads, and coffee urn all day and night etc... it was not a fair go really...

Apart form that event, there has been no generator support that I know of on the other sites.
As a rough rule of thumb at 40 degrees south, if you normally use 15kwh/day then use 15kw of solar panels.... if that includes hot water, maybe a few more.

If you don't go silly on the very dark days, ( not just overcast, but dark) you should only use the genny for maintenance starts.. just to see if it still starts.

I find that 10kw will generate about 8-10 amps in truly terrible light ( 48v system), and more than you can choke on when it is light cloud or sun.... thats 400-500w.

If the heavy cloud brightens up even a little bit, your suddenly up in the 20-40 amp and more but still 8/8 cloud and pretty heavy... 8/8 cloud of single layer, and your back up in the 40-80 amps range... so it takes a miserable day to pull you down.

If you go up to the 15kw arrays, your making more than normal quiescent current no matter what the weather is, and should get 6-7kwh at the very worst... you can live with this as a generality... ie fridges, freezers, lighting and most other stuff except for heating and cooling and hot water.

With the cost of solar panels now, particularly second hand 250 watt panels, that 15kw array is cheap as nuts.... probably in the $7000 range, which leaves $6000 for batteries... and thats too much really, and a few thousand for inverter and controller and fixing materials.

Lets be clear, there is no need for a monster battery or an expensive battery, better to use golf cart ones that will last 5 years, and replace them every 5 years.

6x220ah american batteries can be found for $200, so a 24 battery bank will only be $5000 ( you will probably get more years than that as they will rarely be discharged beyond 25%... and that should give 3000 cycles)

Stylish expensive cells ( whilst I like them very much) are not necessary to produce a better system.

Panels are key and the only thing that is critical, charge controllers are of little interest if you make your own, and mppt is next to useless for this setup... simple 150amp pwm will do fine... maybe $100, inverter around the $300 if using aerosharps or inspires.... point the panels any where you have access too. N, S, E ,W.... east is particularly useful to get the recharge going early, so a 3-4 kw looking east is a good thing, a few kw west, the rest can be almost flat... just enough to self clean, pointing any place.

It really is cheap to go off grid if you ignore the experts, and their fancy add on's.

You only need expensive add ons ( auto generator support and fancy software in your inverter) if your system is inadequate to start with, and now that can be solved with panels..... and you can build 2 of everything for next to nothing so redundancy is a given.

The world has changed simply because power is easy to get now panels are cheap. Thats my 2 cents worth, and it is working on installations down here.

Inverters are now only about $100 to build the electronics now, so I have plenty of spare change over units now.  ( oddly, non have failed yet... I felt sure the island ones would as they are the hardest to get to... but no..)

When the name brands fail ( and they do), it has taken weeks for the owners over here to get back on line.... no fault of the australian manufacturers/agents, but remoteness is everything, and real inverters are not trivial to transport off island and back... could build half a dozen for just the cost of freight alone if we use air freight.

All kinds of things become irrelevant, such as cooling for panels.. we don't want any, so you can clamp directly to the roof if you want, as ventilation is a waste of effort.. we actually want attenuation when it gets hot... coz that means the suns out, and we have probably 7 times the power we actually want then... some losses would be more than welcome. Line loss is a good thing now for the same reason.. when there is lots of current, there is actually way way too much, so losses are irrelevant too, and when the light is poor, the losses will be tiny/non-existent.

Mppt is useless for the same reason, may help when the light is poor, but that will be very rare for the complicated electronics that that brings, and the thousands of dollars that will add to the system.. for what? (15kw of mppt is not cheap... 15kw of pwm is a hundred bucks or so)

But I am the village idiot after all, and am a bit different in my views too.

I will do a thing on the solar controller soon ( Time??? ), and a thing on how to modify the 39 dollar 350w 48v pwm power supplies ( led lighting they use them for) to use as battery chargers. They should work off the shelf, but they don't have adequate o/current protection, so last night I fixed up the three that I blew up testing them( they lasted 10 seconds), and added current control.... now it is a proper tough charging alternative... ie a 40 amp charger for 48v system (38 up to 58v) is now $240 dollars and free shipping.... so you can set the current and the voltage ( I would set for 56... and leave it) Thats 6 units in parallel... and you can keep paralleling them..

'Oztules' can write and get his point over far better than I can.

2017 April ........ I now use the second hand/used GTI, (Grid tied Inverters) taking 10kW of PV. Our 48vdc to 230vac Pure Sine Wave OzInverter, can take the GTI input and charge backwards to the batteries.
And yes the OzInverter can be set at 60HZ or 50HZ or 230vac to 110vac.

Although I still have 5kW of PV charging the batteries on independent charge controllers just to finish/float my precious 1300ah, 48v batteries.

Perhaps some members here could put a booklet together on the real actual basics? ......

« Last Edit: April 17, 2017, 02:25:05 AM by clockmanFRA »
Everything is possible, just give me time.

OzInverter man. Normandy France.

3off Hugh P's 3.7m Wind T's (9 years).  .. 5kW PV on 3 Trackers, (5 yrs) .. 9kW PV AC coupled Used/SH GTI's, on my OzInverter created Grid, and back charging with AC Coupling to the OzInverter to my 48v 1300ah batteries.

Mary B

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Re: Best Off Grid Set Up?
« Reply #37 on: April 17, 2017, 02:31:27 PM »
I would not want to be a ham radio operator within 10 miles of 15kw of PWM! Can you say RFI?