Main solar system upgrade

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DCFusor

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First sunny day since we finished, so I took a pic. The array is making something over 4kw at 11 am today, pretty much what my house uses plus what my Volt draws - it's keeping even with all that. Pretty cool! There are two more racks of panels to put up on another building behind this one, that gets better sun in winter, and needs shade on its roof in summer worse than this one, so we left a blank spot on the main building for the future.
This was HARD WORK, but I like the payoff. I'd like to claim I designed the very effective convection channels into this, but they are just a result of being cheap and using 2x8"s for rails. There's enough wind up at the top to make running a propane torch impossible - which we found out when it was time to wire all this up. I have a half-fantasy that I will buy a foam matress and cut it up to make plugs for those channels for winter - hold in more heat. We'll see.

I put this in BSTS because hey - if things go bad, a system like this will be worth more to me than the equivalent price stack of gold. I feel like it's wise to take care of the basics first - be independent, then do the rest.

Now to plant up that garden a friend tilled for me while we were putting up the finishing touches on the panel mounts....more here:
http://www.coultersmithing.com/forums/viewtopic.php?f=48&t=563

Upgrade.jpg
 
Very nice indeed!

This picture doesn't do the project scale proper justice. Everyone should follow the link you provided to see just how extensive a project this is.
 
...good stuff, Fusor! I like what you say about shading the roof - having that convection blowing on the back of your panels + shade, it is a double win. I wonder, if having some drip "irrigation" + some wicking material inside these tunnels, would not be worth the hassle of trying it? With water latent heat, evaporating from the air movement, you could go lover than env. temps, on the back of your panels - and have some aircooled roofspace, in one go? something like simplified version of swamp coolers. Curious.


Was about to ask you, any hints regarding specific panels/makers, for Irish (cloudy) climate - I remember you mentioned polycrystalline works better on cloudy days? Also I know you warn against cheap panels - I would rather buy something that would last (from your experience).

I am considering going off-grid on my aquaponics setup (still in progress), since there's (comparatively) very little power required, and it would save me the hassle of connecting polytunnel to the grid in a safe way. So it might be worth going for, from get go. Just some small simple autonomous system with a panel, battery(ies), charge controller and a 12V pump. All should work out relatively cheap, because of the small scale.
 
Ancona is right - that was one huge project, took a couple weeks last year and a couple this year (with 2-3 people helping) - crane rent alone was about $1500. The real issue was I'm an idiot at major sky-lift construction projects, lifting things I can't lift into places I can't reach to bolt them down...

But by the last couple racks, we had that figured out and they were nearly effortless.
A lot of jobs a homesteader does are like that - you get good at it just as it's finished for good...

I'd like to give good advice on panels, but at the moment, the ones I've liked best and have been proven in real life here - are no longer made - they were BP solar. They've lived through hail the size of quarters, windstorms, you name it.
The lighter blue sparkly ones are over 30 years old and still pumping out the juice.

The big ones on the right of the pic are great, but are only a year old and I have no idea if they'll withstand all those slings and arrows - at least they were cheap (about $1/watt). They are Schott (the German glass company, but made in USA in the SW, or these were - Schott is all over the world). They are very efficient - but they had to ship me 20+ of them for me to receive 12 that weren't broken in shipping - not a great sign - the local vendor dropped the brand as a result. Could be the Germans got a little proud of their ability to make super good glass (Schott is well known for this in the physics biz) and went too thin with these. They aren't very rigid, I can say that, where with the BP ones, you might as well be holding a chunk of plywood.

Companies that have been out there "forever" - Their stuff has to be good, and people do say so - I don't have any of these myself, however.
Kyocera
Sharp
and a couple others (I'll look around more and jog my memory) - look for "Not Chinese" IMO (and all that is is opinion but I don't see a good track record from them so far). As a trader (I assume most here are) pull their financials off google finance and see if they're doing well and have been around awhile to prove it.

Avoid:
Canadian solar - they're really Chinese and dishonest as hell at the top - dilute their stock at will without warning. If management is that bad, I'd bet their warranty, quality etc can't be that much better. They are the dryships of the solar biz.

Also avoid thin film or amorphous panels, I've tried many and all have failed, usually the company goes bankrupt just as the claims for new ones come in. Just not worth it. If a company hasn't been in business at least 5-10 years, I'd avoid them, this stuff is too expensive to be a guinea pig for them. And much of the cost isn't the panels, it's the other stuff - getting them mounted in a good spot ain't cheap or easy.
Even if you got free replacements, you don't want to have to do that over.

For a greenhouse operation you might not need the full setup, depends on your demands. A local farmer is doing this with some success. All he needs is a fan running when the sun shines and it's too hot in his greenhouse (plastic over hoops, but a huge one). We set him up with a few panels, and used a belt-drive fan with a special DC motor (not that special, but 3/4 horse at 90v nominal, permanent magnet brush motor, which is a standard thing for stuff like conveyer belt drives, they're out there cheap, surplus). This actually works pretty well - when there's less sun, the motor just spins slower - just as you want.

Back in the day, there was something even better for that for water/well pumps, I'll look around and see if they still exist. They'd drop the voltage to the motor to where the amps were high enough to keep it spinning in much lower sun insolation than a straight hookup would give (they are effectively DC to DC variable ratio transformers that harvest the most power from the panels, then deliver it to the load - a dynamic "impedance match"). For my farmer pal, it works without that, but he did buy extra panels, more than required to do his job. He's just that type of conservative.

If you want UPS power, yeah, you gotta get the batteries and solar controllers, and an inverter, which are over half the cost of a decent system. But you might not need that - I'd have to know more about your needs to give you good advice there. If you get solar controllers, look for MPPT in the specs. That's maximum power point tracking.
Panels have a voltage at which they put out best power - load them below that voltage and the current doesn't go up to match, let them get higher and they start eating their own output (the diodes are forward biased in a panel). This magic load changes with temperature and how bright the sun is - and an MPPT controller gives you 30-50% more power just when you need it most - in crummy, chilly, rainy weather. So any decent sized system is worth the extra money for that, it beats buying more panels.

FWIW, I'm using Xantrex for all the electronics now - out of almost 4 decades of using their stuff, I've only gotten one turkey (a badly designed too-cheap inverter).
Their MPPT controllers are on the pricey side, but network over a CAN bus with your inverter and have a really nice remote display/control panel that feels pretty lux, and works nicely. I'm sure there are some other brands that are good, this is just what I've wound up liking the best myself. Their sine wave inverters are totally top notch - one rated for 4kw will actually do nearly 40kw for short periods (minutes). You just can't break one. Dead short it - it shuts down in mid cycle - not even a spark.

Hook one up to 50 feet of #16 wire, shorted at the far end - the wire burns up. It's kind of nice...One of those is what the contractors used to build my shack here. They didn't think it would do, but it did. It shut down one time when one of them had a dead short in his circular saw cable - he said it wasn't that, since there wasn't the usual shower of sparks, but since he was sick and in the doctor's office, so to speak, I took his saw apart and fixed it, pushed the reset button on the inverter, and no further problems - with saws and air compressors running off it.

Here's the skinny on MPPT:
MPP.gif
Remember, that point changes with temperature and sun insolation, else you wouldn't need the "tracking" intelligence in the thing. So, hooking panels straight up to batteries is not the way.

Edit:
Most of the time when you need it most, it's too humid here for wick/water chilling, so I didn't consider that for this lashup. I really don't need it anyway, it'd just be another thing to have to keep fixed in an unhandy location - I'm getting too old for that.

In fact, my next project is to finally finish up the rainwater collection system. Right now, I have a 40 gal tank on the downspout - which is way too small - it overflows in a few minutes of rain - and only 80 gal in a cistern for the plumbed building, also too small if I anticipate (and I do) having a woman around. I'll be buying about $1k of big stock tanks and installing those. I have a pretty nifty system now - for my water-thrifty self, but it could be better. I can drink this water all but a couple weeks out of the year, when it's pollen seasons. I sent a sample off to VA Tech to measure, and I got back "you're kidding, you just sent us distilled water, right?". It's still drinkable with the pollen, but any part out in the sun (the collection tank) grows algae like stink if you don't put in some chlorine or other algae killer...with a big enough cistern, that won't matter, I'll just dump the "polluted" stuff out. The collection tank has some nifty low-tech to it. There's a plastic window screen on a frame stretched over the top - keeps the roof-shingle rocks, leaves, etc out. There is an overflow hole near the top too, that skims off any floating junk (most of the pollen). Then, the pickup isn't quite at the bottom, so things that sink can collect there for about a once/6 month cleanout but they don't get into the plumbing. This gravity feeds into my main cistern with a valve, so I can choose when to do it. That cistern is in a crawl space, so no storage issues there - it stays not-frozen and won't grow algae.
 
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Uh..I'll wait till the new tech kicks in with thinner lighter panels doing the same job.

-Q
 
Good luck with that - I've seen and in some cases tested that "new tech" and frankly, it sucks.
What kills panels is water getting in - and temperature cycling due to the expansion tempcos of the parts not matching. That's what you're paying for with the stuff I have - matched tempcos (no small thing to match silicon, glass, and the backing plastic), real (flexible) silver interconnects, and hermeticity that's good for decades.
That just takes both the right materials and the right amount - and very high quality build, NASA grade or better.

Going cheap is dumb, means it won't live very long as some major players have already found out (Google for example, and WalMart got really burned).
I also found that out the hard way. You just can't skimp on that stuff. You wind up losing money in the end.

It'd be like waiting for hydrogen powered cars, which is how Bush spun things so he and his buddies could keep you buying their oil (because H powered cars ain't gonna happen)...There's no free in physics and nature, at least not that kind.

But to each his own - if TSHTF, there won't be anything to buy at all in this line. And how are you going to barter/trade for electricity if no one has any or the price becomes ruinous? Generator electricity, at the current price of gas and generators, cost you about $1.64 a kwh - generators aren't too efficient in the main, and do wear out.

When I started out on this journey, the payout time was calculated at 30 years, and all my neighbors thought I was nuts. But...the price of power co power tripled, and the price of the solar gear went down a factor of 6, so I just DCA'd into all this - hence all the different looking panels and so on.

They used to ask me "how can you live like this?" when my stuff wasn't up to (their idea of) snuff. But I had no - zero - debt, either. Now they're being foreclosed and pinched by power prices, and think I'm a genius. Go figure. You pays your money and takes your chances. This one turned out well IMO.

And now I can drive my car 50 miles on the charge it got this morning without a drop of gasoline...or a penny on a monthly electric bill. I think it's not so shabby a plan.

And, oh yes, going the other way? The Volt engine runs 90 seconds every 15 minutes or so to push 600w into my house batteries, should I need a backup...and uses less gas than the most efficient inverter-generator you can buy doing it. I suspect that run rate won't wear out its engine really quick, just screw up my gas mileage numbers some.

For me, this job is done and done. Now onto some other aspect of self-sufficiency.
 
Forgive as I'm not very familiar and my comment was based on some research a buddy of mine spoke about not too long ago.

I found this on Amazon.

[ame="http://www.amazon.com/Unisolar-Flexible-solar-panels-laminate/dp/B00573ZADW"]Amazon.com: 3 pack 68 watt 12V Unisolar Flexible solar panels laminate. Made in USA.: Everything Else@@AMEPARAM@@http://ecx.images-amazon.com/images/I/2167YyZQ6WL.@@AMEPARAM@@2167YyZQ6WL[/ame]

Are these crap? A person left a comment he uses them for his cabin.

I'm really wanting to be educated here. :)

-Q
 
Hahaha, Q - there's a learning curve here at PMBug - and the first rule says, "when DCFusor says it is better to be done such and such way" - then you better bloody listen, OR have a really, REALLY good understanding of the matter you disagree on - or you pay the price, of learning the hard way :)

Sent from my Nexus 7 using Tapatalk 2
 
Gee Bushi, flattery? I'm not that super smart. Just old and been around a lot.

I can't say if those particular ones are crap, but likely they are. They also calculate out to about 2.2x the price/watt I paid for my newer panels...We are seeing under $1/watt these days for the "real thing". If you have a cabin - why bother with camping gear? You have a nice straight roof to put stuff on and it doesn't need flex.

You of course like your panels high up enough to avoid shade from trees, I have that issue here, with trees to the south I don't want to cut down. So I had to go on the roof, or build another building in essence. 12 feet up isn't high enough, they're in the shade all winter if I do that.

I tried that kind of stuff at first, had a 12v system with truck batteries, and used car accessories for lights, immersion water heater for tea, and such - camper stuff - and amorphous silicon panels like that (all failed inside 6 months, but so did the company and warranty). It was NOT a good plan. Truck batteries aren't designed for cycling and go bad quick (and one blew up on me when I made a spark at the wrong moment near it, ouch - long story, but once I got the sulphuric acid out of my eyes, I felt better). I used #1156 car lamps and such - which are to say the least, a heck of a lot less efficient than today's CCFLs and LEDs.

I found that at a certain scale (like, staying alive and actually living on this stuff) - it's better to do the thing with real high quality (I use Rolls-Surrette batteries, same as the submarines use), just get an efficient sine wave inverter, and use the most efficient normal stuff for all your appliances. Everything, and I mean everything here, is on a power strip to eliminate "vampire loads" like that clock on the VCR, the TV that draws power waiting for a signal from the remote, everything. You'd be surprised how much most medium-modern appliances waste - after all the maker isn't paying your bill. This is especially true of anything consumer grade with induction motors in it - they use the least possible copper and iron to make it cheap.
So you get 50% or less efficiency, instead of the high 90's possible with a slightly more expensive motor you can get from McMaster or Grainger. It's way worth it to do the conversion...

Anybody who wants to think of doing this kind of thing - get a Kill A Watt or something like it and find out where all your power is going. You're going to crap your pants when you find out your telco router is drawing 60 watts 24hr a day and stuff like that - and so are a lot of other things. In other words, you'll find most of your KWH are utterly wasted on things you don't even think are "on"....which is interesting by itself.

The really new stuff is getting a lot better. Someone caught a clue a few years after the energy star thing got popular, but you still have to really pay attention to the actual numbers - there's ways to spin that like anything, and compare against something so bad the thing you see in the store is good by comparison. Things you can't turn off are evil - like the fridge - it draws power when it pleases, no matter the state of batteries or weather, so that's the first big one you have to get right, and it takes a lot of panels/batteries to even manage a good quality dorm-room sized one if you aren't willing to run a generator in say, February. And if you have a generator, you can't just let it lie around, you have to run it some or when you need it, it'll be hydrolocked with condensation, stuck valves, water in the gas, no spark, you name it.
That's why I like my Volt as a backup. It was designed to live out in the weather, unlike anything you get at the hardware store, and it was also designed as efficient as modern tech can be - no throttle, it's all variable valve timing and computer spark/fuel control...stuff like that you can't buy in a purpose built generator.

What we did here for years was get the smallest and most efficient chest freezer we could find, and in addition to the normal use, freeze 2 liter pop bottles of water in it, and use them to cool big, high quality camping coolers used as fridges in two homes here. We could control when the freezer kicked in by when we changed out the bottles. We also put it in an unheated storage shed in the woods - so it ran a lot less than in a warm house. Those where the days when a 600w solar system was big (and panels were $6/watt!). Now with 6-7kw of panels (at least, but I've not measured this lashup accurately yet) and 24kwh of batteries, well, things are better to say the least.

Things like microwaves and toasters use diddly kilowatt hours, since they only run for short periods. So I use them, but the rest of my cooking is gas. Heating is split between wood (daytime) and gas (nighttime so I don't have to get up in the middle of the night). I also have a mattress heating pad that lets me run the house cooler than usual and still be comfortable - it sips the power.

I have a full machine shop - lathe, mill, drill presses, every welder known to man. Again, those don't use many kilowatt hours - you spend all your time in setup, then the machine does it in seconds. So while the peak loads are crazy big, the average is way under 500w for my whole home when not running A/C, which is nearly all the time. I DO use a tiny electric water heater, but plan to go to a demand propane type someday instead. I just don't use that much hot water at present. It's a hog, the car is a BIG HOG - 13.3 kwh from dead to full. But since I'm retired, I only have to drive it when I run out of stuff, not that often in other words.

Bushi - there is a website for the US that shows how many noon-equivalent sun hours a day you'd get vs where you are. Maybe there is one for your country - look and maybe find that. Those are very handy when it comes to sizing a system - they take the sometimes cloudy weather into account. Of course, you never get that average, which for me is 4.5/day. In summer, sunny day, I get 10 good hours. Winter, I sometimes get a week with no full sun at all...turns out it's cheaper to have a generator than to try to size that large a battery bank (there's this thing they do called self-discharge, you don't want them too large).

What are the demands of your aquaponics system? If we can figure that out, I can help you. Is there stuff that has to run 24/7? If not, it's a lot easier, if so, you spend a fair amount of effort finding stuff that will be super-efficient, to avoid too much round-trip loss in the battery system.
 
...

Well that is fantastic work, DCFusor, I think you have impressed us all!

Um, but for a Bearing that is allergic to very much work, um, um...

:wave:
 
Hi Fusor,

YEah, there are things that need to run 24/7 in aquaponics - like water aeration... But that uses close to no power, and can be used as a backup only - normally, the flow of water through the pebble growbeds, plus things like a Venturi aerator somewhere in your main water loop, would suffice - as long as your pump works OK. So aeration stone, is rather a backup device, in case of "ze germans" - and your fish would suffocate much quicker than die from self-peeing & resulting water toxicity - so you'd probably want to have that backup in case your pump fries, AND you'd want to have it running off the battery anyways - in case that the reason of your main pupm sbeing shut, is mains power failure of any kind (I mean grid/off grid main installation).

Main hog would be a pump - one that can displace max. 2000 ltr/hourly cycle (over est.), with a head of roughly 1-1.2 meter (2m max, over est.). Most probably, running in 15 mins work cycle/45 mins pause. It doesn't need to run as often during the night (it is even not recommended, because of some stuff with "reversed photosynthesis" in plants, apparently happening at night, that puts shit into water that we don't want to be there. Don't remember the details of that one (was it CO2, that goes into water at dark times - don't remember), only the fact that you don't really need to cycle water at night, other than for aeration. So I think it could be switched to aeration stone on timer, for the night - to save power.

I haven't come to any power requirements calculations, but I feel it in my pee that something off the shelf, for cabins/marine use, can possibly suffice in this case.

Thanks for sharing your experience already :). Nothing like experience, if we talk about tinkering with stuff :). And it is all too true, with one-off stuff like that - you perfect your process, just when you are finishing with something - happened to me all the time :). But the satisfaction, the sense of achievement, and experience remains :)

EDIT:

Re: insolation levels for Ireland, I've looked here and there, and this page seems to bequite comprehensive
http://www.solarbook.ie/solar-insolation.html

gives the following graph & table (they seem to be qouted on every solar installer site here in Ireland
direct-diffuse.gif

diffuse_table.gif
 
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BTW, Fusor, have you heard of rocket stove mass heaters - seem to be a great match for a well-insulated house the size of yours, they burn very little wood completely at very high temps, harvest nearly all the heat from the burn (including heat from the fumes - they leave the chimney barely warmer than env. temp) and then release low, nice heat over the next 24-30something hours - so things like heating overnight, without using gas - they are perfectly capable of that. Great place to start looking at them:

http://www.richsoil.com/rocket-stove-mass-heater.jsp

and the short introduction video from one of the more knowledgeable guys in the area (that I've found on the 'Net) , from the page above:
 
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I'm pretty happy with my heating situation, it's just that when it gets REALLY cold and very windy at the same time, you just can't shove enough fuel into a 55 gal drum heater with the proper burn rate (it's adjustable) to last all night when you adjust for "crank out max BTUs". So I have backups...depends on the winter - we never get two years in a row the same. I have a thermostatic inlet air control on mine, it does a good job for me. It's a part of my winter ventilation system. The stove is at one corner of the ground floor, with the one partly open window next to it. A fan diagonally opposite, in a hole in the floor, sucks in air, which has to flow over the stove on the way in, and pushes the colder floor air (which is still warmer than outside by a good bit) into the crawl space, which is vented at the opposite end of the building - it's where the cats hang out in winter, and it keeps the basement warm and dry. I'm probably the only guy who has this kind of thing in the same room as
a high vacuum system, and have even done vapor phase reflow soldering of surface mount parts on PCBs using the stove as the heat...crazy, but it works. This keeps my ground floor warm - nice to have warm floors.

Here's some pix that show the stove and some of my toys.
https://plus.google.com/photos/1182...ms/5833740941937051777?authkey=CIaw78P19YXMAw

The flue pipe is all indoors up to the roof on the second floor, and the main problem I have is it's almost too good at removing all the flue gas heat and putting it into the house - it runs cool by the time it exits, meaning I have to pay attention to tar condensing in it. As luck would have it, thermal cycling cracks that stuff (creosote) off the walls and it falls back into the stove to burn, so I rarely have to play chimney sweep - and knowing that, I'm also a bit careful what wood I burn in there - I have pretty good choices that would make woodworkers weep - Cherry, Walnut, Hickory, Red Oak, White Oak, Birch....I don't burn pine unless it's some junk I cut to clean up the place. The airflow through the drum is preheated and carefully set up - best I've seen or used yet. There's never unburned wood in there after a fire. Very clean burn, nice.


Looks like you need (in my units) about 8 gpm. I have found one really good pump in that range, wish I knew where to get more at any price at the moment. It's 6 gpm and draws under 100w - with a freaking induction motor (and it's quiet)! I use it in the water-getter I described here in another thread awhile back. What that means is that the same mechanism driven by a truly efficient motor would do 8 at perhaps somewhat less power than that.

I use fish-store aeration pumps here for my electroplating, and as you say - it's not a lot of power, and the new ones don't have much of that old annoying buzz, since they are twin cylinder and smooth out the pulsing. I got the "deep tank" ones sold for keeping saltwater fish. They work great and are cheap.

So, the thing to do is create a custom pump or find one designed with efficiency in mind. Some of the boating bilge pumps are quite well designed and in the range of the spec (they exist bigger and smaller both) - and aren't really that expensive, though you'd be replacing them yearly or thereabouts - a sealed in brush motor wears out eventually, and it's usually the bearings, not the brushes.

Believe it or not, there are still plenty of pumps out there designed by guys who don't "get" water flow, and only a few with properly designed vanes and flow chamber. I can get you more info on those, and they don't mind eating a bit of dirt in the flow. They tend to run on 12v DC, a handy thing in some cases.

I'm not sure how to interpret the chart above - kwh in what square area, with what efficiency? Is that kwh/sq meter raw (before the PV efficiency of ~~ 17%)?
It would seem by the numbers they are giving monthly raw figures per sq meter per month - I'll have to back-fit that to some units I can use to figure. Using noon-equivalent sun hours makes it easier, as we mostly do here, since that can simply be multiplied by panel output ratings to get your daily number (which as noted, is different at different times of year).

If you've also got grid, you can get an inverter that will charge the batteries off the grid when the panels aren't doing enough, then provide power in grid dropouts - you don't even need panels for that. Stepping back down from the grid voltages efficiently to 12v for example is not expensive or inefficient - most computer power supplies do it fine and are cheap as those things go. There are other variations of switching power supplies out there cheap surplus. No problems there.

The key in your case is going to be finding/building/inventing/whatever the most efficient water pump possible. There are some really good, very efficient electric motors out there, and some good pumps - just have to pick one from each column and put 'em together. I don't see much out there that's just so, off the shelf - it's been an item of interest around here too, for solar heat collection and there's just not much out there that assumes you care about how much power it eats at present.

Most small AC motors are terrible - 50% efficient is considered great. Most DC permanent magnet motors, of a few flavors (some require some electronics to replace brushes, usually built in, more cost but infinite life) - hit high 90's%, and that is all the difference - half the power to do the same job. Similar differences exist in how much mech energy a pump takes to move X water at Y head. Get the best of both and you're gonna be real happy.

My good one has a plastic curved-right vane-set running on graphite bearings over a ceramic shaft and has seen a few tens of thousands of hours use with no visible wear whatever - that's what you want. The bilge pumps are second best at most - they do wear out if used all day every day, and you can't fix them - all potted into epoxy for complete submersion. The trick with the boat stuff is never buy it at a boat-stuff store, where it costs 3-5x more than anyplace else - if you've got "a hole in the water you attempt to fill with money" they kind of see you coming...Never buy at a marina, but sometimes a hardware store near the water has them at a more-decent price.
 
...moved that there from another topic:

speaking of generators, Fusor - have you ever considered building Stirling engine generator, running off your main heat source (wood stove)? Just interested in your answer, because you seem to have explored most of the available options of energy efficiency in a homestead, known to mankind .

I know there are commercial STirling engine "micro co-generators" (Combined Heat & Power) now available (Whispergen), running on NatGas, but these are primarily heat, electricity second (and that's probably how it would work anyway, with the efficiency realistically available at such scales)


here it is, specified as 14kW heat, 1kW electric. Not cheap, these babies as sold from them, BTW:
http://www.whispergen-europe.com/productspec_en.php?fm=whispergen&fp=Product Specs
 
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The flue pipe is all indoors up to the roof on the second floor, and the main problem I have is it's almost too good at removing all the flue gas heat and putting it into the house - it runs cool by the time it exits, meaning I have to pay attention to tar condensing in it. As luck would have it, thermal cycling cracks that stuff (creosote) off the walls and it falls back into the stove to burn, so I rarely have to play chimney sweep - and knowing that, I'm also a bit careful what wood I burn in there - I have pretty good choices that would make woodworkers weep - Cherry, Walnut, Hickory, Red Oak, White Oak, Birch....I don't burn pine unless it's some junk I cut to clean up the place. The airflow through the drum is preheated and carefully set up - best I've seen or used yet. There's never unburned wood in there after a fire. Very clean burn, nice.

yes, having heated my flat few winters mostly with wood stove, I know what you mean. There comes the beauty of rocket mass heaters - it burns extremely hot, in oxygen rich atmosphere, therefore also burns extremely clean. And since the flue goes horizontally, after majority of the heat was extracted, it just continues to "flow" slowly, and keeps extracting the heat, until leaving the house somewhere at the level of fire. Therefore, there's no risk of chimney being "plugged" with fumes, that have been cooled down too much, therefore, getting heavy.

I am cautious myself, because CO is a bitch and a silent killer, so experimental stoves are not to be messed with, without proper consideration, but I must say rocket mass heater design seems damn elegant to me. And people report, they literally, burn fallen branches/hedge trimmings in them. That's it - doesn't get much more "lazy" and efficient (that's including labor required, and environmental impacts) than that!


I'm not sure how to interpret the chart above - kwh in what square area, with what efficiency? Is that kwh/sq meter raw (before the PV efficiency of ~~ 17%)?
It would seem by the numbers they are giving monthly raw figures per sq meter per month
yes that's correct, that's insolation figures, means what our good old sun gives us here per sq meter of GROUND (ie, horizontal area - you can do way better then these, by angling panels to be more perpendicular to the sun through the winter season).


BTW, many thanks for all the info in the post above, I was doing my homework and looking for the pumps that you've described - seems there are few available with ceramic shafts, and decent flows, achieved under decent wattage, that even don't cost you a kidney! I'd assume, that having a good flow, good pressure (as measured by max head), and all the same, decent energy usage (way lower than 100W you mention - in the range 30ish to 60ish, the ones I have shortlisted), would suggest decent propeller/chamber design? All these goodies combined cannot be achieved with wasteful hydrodynamics, I suppose.

One other thing I've learned to look for, is real-life users testimonies, with regards of "clog-ability" of the pump - while the only solids I expect to be required to chew through, is fish poo, I suspect there will be and odd thing or two sometimes, but the more "fire & forget" it is, the better.

I've also learned what you were suggesting previously, with regards of other appliances - it is often better to get some really good (or top-notch), but off the shelf stuff, like 220V pump (designed as grid connected), and small & efficient inverter to run it off 12V batteries, rather than going for dedicated 12V gear - most of these is rubbish, not really designed to be robust and last. And when you can figure that out, by LOOKING at the pictures online - man, it means these are really BAD :). I suppose you could perhaps GET the dedicated 12V gear that is robust and everything - but since it wopuld be "niche", it would cost you several folds more, while not offering anything significantly more, in practical terms. Funny little world!


man, I am longing for my OWN place to put all these things together permanently, like you did - but hey, you have to start somewhere, and my landlord is OK with these - so hell why not, I can reassemble these in my own place afterwards!
 
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I've looked into a few alternatives for generators, but the best solution seems to be not to need one (no surprise). I've seen that one you linked before - it IS quite expensive, and when you can't use the heat...well, just not worth it.

I have been known to capture and use the waste heat from a conventional generator, which can be a little dangerous to it and to you (the CO issue). Thing is, they are also noisy in general, and to get the heat out and use it - you kinda have to be close to it...PITA, not worth it - have to integrate all that into the other heat systems on top so you don't have too much sometimes, stuff like that. The current use of this waste heat is to melt snow off the solar panels, since all that is already outdoors - and once that's done, you don't need the juice from the generator anyway.

I don't like the Stirling due to its complexity and slow speed, which requires either a zillion poles in the generator/alternator part, or gearing things up - which loses more than you might have gained by using that tech in the first place. Low frequency generators are a bear to make, and make efficient, is what that comes down to - more copper and iron are needed, as well as more poles. Gets expensive quick.

I've been looking into various steam solutions, and have designed a turbine that looks good to me, as it's reasonable at getting the energy out of steam, requires no shaft seals (generator in the box with it), and can handle huge variations in steam - an absolute requirement for a home (dumb user) situation - it's very difficult to keep a fire just so, and boiler explosions are no joke. So I designed a two stage turbine, the first stage of which resembles a pelton and which has multiple feed jets - some of which are auto-valved off at low steam pressure, but which are available to "eat" a high steam availability. You don't want to just vent off excess steam for a lot of reasons, you want to use it if it's there, but still be able to run when it's not. The second stage is more conventional and gets about 20% more output. After that, cost rises faster than the increase in efficiency unless you go to really complex reheat/regen schemes like a power plant uses. And then there's the whole closed vs open system issue. Closed systems maintain water purity well...but cost a heck of a lot more for a decent condenser. Open circuit schemes require a lot of very pure water, already a problem in many places, and a lot more maintenance - if you let scale build up inside boiler tubes, you get some scary issues.

I highly recommend the book "Steam, its Generation and Uses) by Babcock and Wilcox, often found in used book stores - there's more there than you'd think possible about all these tradeoffs. You can also buy one from them, but the price is kinda high, and really - water has been water for a very long time, so old copies are fine. These are the guys who made the first safe steam boilers, and who designed most of the really big heat engines now in use worldwide, it's a heck of a book.

But either means a multi month project to build and refine, at least, with considerable materials required...at present such things are not high on my priority list - I no longer need external generation, or not nearly as much. It's become an issue of now I have to run the ones I have once in awhile in a near complete waste of fuel and wear just to keep them "ready".

I was thinking of the steam thing as potentially a product for 3rd world (which can include US if you look around), but there are some issues yet to solve with "stupid users" - because the amount of potentially stored energy, the possible lack of maintenance (and use of inappropriate water - boiler scale and corrosion), or simply someone building too hot or not hot enough fire, or letting the system run too dry...Taking care of all these things without a yet more elegant design (which potentially could eliminate some needs for complexity) implies quite a lot of overhead for safety and control, which becomes its own reliability problem (and cost) at some point, and I'm not happy that my vision is complete enough yet. Think "litigation" if I do make that project and something screws up - especially in the US, it's pretty fierce out there. It's very hard to make some things stupid proof or at least resistant.

I'm pretty happy with the stove I have now. It's pretty rare to see much CO out of it (it has preheated main air and a secondary air inlet to finish a burn of anything flammable in the flue gas), it burns anything (from junk mail or coal on up to cherry/oak/locust wood) and has a very clean burn - in 6-7 years there's no creosote buildup in the flue - this is at least partly due to my careful use of fuel, and not putting in the wrong stuff (too much green wood for example). Heat is well distributed between the floors of the building as well - not a trivial thing. It also has very quick response - when you want heat, you get it right off. All solid fuel stoves of course can be a problem to get stopped - for weather with nippy mornings but warm afternoons (much of the year here), I just use propane at present - it's not a big expense as things go and easy to turn off when enough heat has been delivered.

As I've found "out here", there is considerable utility in having multiple backup ways to do any major thing. Stuff fails at the worst possible moment, it seems, and the idea of having a "hot spare" of whatever is very valid, at least up to the point where keeping all the hot spares in for-sure operational condition becomes too much work.

You can't let a generator, say, sit for 6 months - it will fill with water of condensation, even if you are careful about storing it with the valves shut - and this extends even to potted spark coils - a real problem. It will also pollute its oil from that, and all the oil creeps off the piston rings/cylinder walls, for example - so rust can happen, or just a very-annoying temporary loss of compression, which makes it very hard to start. I use a Makita half inch drill with 3/4" socket drive to spin those suckers till they start - much faster RPM than a conventional electric start, enough to get oil up on things - you just take the pull-start part off the thing to use this, and toss it in the trash - the drill is a lot better way than giving yourself a heart attack yanking a cord endlessly.
 
...true, I suppose, nothing beats solar, when you count in wear & maintenance costs... Solid state is a solid state!
 
Hi Fusor,

Would you be able to say anything about that one, anything that smells fishy from the first look?

[ame="http://www.amazon.co.uk/gp/product/B007R3OOLY/ref=ox_sc_sfl_title_2?ie=UTF8&psc=1&smid=A2K9CLANJ8L55P"]Axitec 235W Watt Solar PV Panel - MCS Approved, Photovoltaic, Grid Tied, Polycrystalline For Business Or Domestic Use: Amazon.co.uk: Lighting@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41TV6KwgnQL.@@AMEPARAM@@41TV6KwgnQL[/ame]

thanks in advance,
M
 
from - http://www.sciencedaily.com/releases/2013/09/130909131230.htm

where they gonna get ze gold from, for this interesting development ? :shrug:


The new work centers on plasmonic nanostructures, specifically, materials fabricated from gold particles and light-sensitive molecules of porphyin, of precise sizes and arranged in specific patterns. Plasmons, or a collective oscillation of electrons, can be excited in these systems by optical radiation and induce an electrical current that can move in a pattern determined by the size and layout of the gold particles, as well as the electrical properties of the surrounding environment.
 
I don't buy things like that from amazon, bushi. Grid tie is anyway more expensive in some ways - an inverter per panel, and less reliable - by law, it has to shut down when the grid does, as it A: has nothing to sync with, and B: might kill a lineman repairing something if it's feeding the grid. So, if the power co goes out, so do you - for me, not having that liability is a major advantage (though I pay for it by having to have batteries).

Yes, there's a lot of exciting new work on meta-materials, nano-stuff. Mostly seems to be applied to things a heck of a lot less efficient than plain old polysilicon solar cells to make them almost competitive in efficiency. I think for now, it's largely a losing game. Don't worry - gold isn't that unique in this game, and as soon as they really understand things, something else will sub for the Au. What I find amusing, but also disgusting is all this "press release science" where they claim gains of 50% over what they had - but what they had was 2% efficiency. The panels in my system, some of which are over 30 years old - 12% for the really old ones, 14.7% for the new. But of course, in the press release they never give the actual total output/sq/lumen....you have to dig for that.

What we really want/need is Robert Heinlien's "Douglass-Martin solar rectifiers". After all, photons are just radio waves, and you should be able to simply capture them "wideband" and rectify the result in fast-enough diodes - which we are approaching now.

But there's this problem. A blue photon has about 3 electron volts energy, and will make in a 100% good barrier rectifier (and modern polysilicon is close) - 3 volts. Whereas a near IR photon might be about 1 volt. If you allow the voltage output of a panel to rise to 3v to get all the power out of the blue, then you lose 100% power from the red - if you load the panel to 1v, you lose 2/3 of the power from the blue.

NASA, for whom no bucks are spared (it's kinda expensive to launch stuff) uses up to 3 layers in each cell. Top layer gets blue/UV, next the midband, last the IR.
It amounts to 3 systems (each a different voltage per cell), but stacked. The top layer lets the lower frequency/energy light through to the rest, and so on. Then you need 3 sets of controllers and so on. Still more power/weight, so they do it even though it's hideously expensive to make. I have a couple of their "rejects" as single cells, and they are fantastic.

This trend towards thin layers is going to discredit a lot of the solar biz. Micro-cracking is a lot more common the thinner something is, and in a series string of cells, you only need one failure to kill it, like the old Christmas tree strings. (the newer series ones have bulbs that auto-short-out if a high voltage appears across the terminals when the filament burns out). Good old thick poly si - that's the way I've gone and never regretted it for a second.

And really - those thin ones are only cheaper than silicon (pretty common stuff!) because they are thin. CdCuTe etc - odd and expensive (and poisonous) metals? I'll let someone else try that first. Oh, they have, and they all fail quite young and the companies go out of business w/o gov support, or even with it.

Right now, I'd do due diligence before buying any panel, and skip any from China, not because they are dumping - they might be, but that's not the point. They're simply not trustworthy as businesses. When you need warranty replacement, who's to say they haven't simply changed their name to avoid having to give you one? It's widely known to have happened a lot of times.

The jury is out on CSIQ, supposedly Canadian solar, but mostly owned/run by Chinese. They have screwed their shareholders in ways reminiscent of DryShips.....at the very least, we know they're not basically an honest outfit - even if they make OK panels (which we don't really know yet).

The German and American stuff seems tops so far in testing, and for life time. Also some Japanese companies are great and have been around the whole time - that's a great sign you've got some quality output - people keep coming back for more, even if it's at a slightly higher price point. Could just be you get what you pay for?

Edit: I'd suggest panels in the 250w range for price/performance - and look at the weight. It's not easy to make something wind/hail and so on resistant and light at the same time - NASA has it easy in space...on earth, thick glass and a stout frame are critical, even if it ups the shipping charges and mounting hassles.
 
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Chatting to an event promoter over the weekend and he reckoned the biggest cost now was the batteries, not the panels.
He was not yet doing his home electricity with solar because he only used about £250 worth a year and he reckoned his battery costs would be a lot greater that this.

No doubt he could get his batterty management a lot better but he did not like the way the panels and event users effected the batteries which seem to prefer steady draw and steady charging.

Think the panels are moving towards the classic 'chinese landfill' status as they cut down on materials and prices continue to fall.

I have learned from your posts Fusor and once again I thank you for taking the time to explain.
 
Trying to be helpful, that's all.

I currently have 24kwh worth of submarine batteries in my system, that cost me $6k installed (well carried in and wired up, I had to build the shed). They have a 25 year warranty, and are made in Canada by Rolls-Surrette. Right now, there's not really anything better out there, though these are expensive per kwh. I'd almost kill for the tech that's in my Volt, it's less lossy, lasts longer, and only getting better with time. Too bad they won't sell them without a core you return, or I'd be running those.

L16's (6v/385 ah) are fairly cheap, and if you take real good care of them - last about 10 years. A minimal 24 system needs 4, I used 8 on my lower-draw building. Since lead-acids are heavy, they are cheapest usually at the nearest distributor - those babies cost to move around long distances.

Battery life has more to do with cycles, and sub-cycles. For example, if a battery lasts ~700 full cycles (typical for a good deep-cycle type), it'll last 7000 1/10th cycles (about 20 years?). If you just float them and never charge/discharge them (just keep them at float volts with only takes a few milliamps) they last longer than a human lifetime - it's cycling the kills them. Luckily it's proportional. Constantly charging and discharging, except for a little near the top of charge is not good for any battery tech currently existing.

I am personally fortunate that I did all this incrementally. First off - the stuff cost a lot more back in the day, so I really had to learn how to conserve (and Dollar cost averaging worked out well - factor of 6 since I began) - I started with 4 50w panels, one light, and one boom box - that's it. Got used to it, everything else is gravy.

The first major upgrade brought in the smallest top-loader freezer I could find, and total panel power of 600w, but I started needing a backup generator some more. I jiggered the thermostat to run it warmer than normal, just a little below freezing. We used that to freeze 2 liter pop bottles full of water, and used quality Coleman coolers as refrigerators with 2-3 bottles apiece in them - sometimes they'd go 2-3 days without melting all the way. That was one cool trick (pun accidental). The thing is, you could then exchange the bottles in the AM on sunny days, and have the freezer run (it was in a storage shed, sheltered from the sun, unheated, in the woods) only when you had the extra power - this avoided cycling the batteries any extra - straight from panels to freezer in that mode. Worked that for about 10-12 years with 8 L16 (big golf cart) batteries, with a little trick - we put a couple of cheap 12v trolling motor batteries across those and those, believe it or not, took the pounding and kept the L16's from having to deliver a lot of peak current - either direction, which is what kills them.
Even those "tiny" 100 ah troling batteries across an ~800 ah pack made the L16's last 12 years (most people get 4-8). Yes, we had to change them about every two years - but those are cheap, easy to lift, and you get a return credit at WalMart. Even though they are much smaller, they actually have more plate square area than the big guys - lots more thinner plates. That's why they die (thin plates warp and fall apart faster under use), and why they naturally take the peaks better.
An electrical engineer would instantly recognize this as using a "bypass capacitor". That's more or less the function of those things.

Then we did the thing depicted here and it's almost like being on the grid. I have a real fridge (dorm room size), electrically heated hot water (with a new trick I'll describe later), all the amenities - even air conditioning, and sometimes electric supplemental heat when there's extra power - may as well use it once the main batteries are full. And that electric car, which I run down about every two days - it's the main power user now (used to be the fridge, and then this big computer - 4 24" hd displays and all the goodies) that I have on all day most days. But I've upgraded the big 'puter to LED displays, an i5, and SSD's and now that whole rig comes in under 150w - with all 4 hd displays going.

But conservation was and is key. Every single thing around here is on a power strip - the type that DOES NOT have a surge protector - no need for that, and it wastes power even with the thing off.
You'd be astonished how much that cuts your use when all those 5-20 watt "vampire loads" are gone from running 24/7 when you don't need them. Things like soft-on TV's, microwave ovens, cable boxes, and the filters in home entertainment systems all draw a bit, and it adds up to a couple hundred watts even here where I took care to buy the right ones. But...they spend almost all their time fully powered down, and I only hit the power strip on when I need whatever that thing is.
That's a lot of kwh a day - .2x24 is half a kwh that I don't cycle through my batteries, even though I do indeed have the panel power to make up for that - I'm conserving battery life here and rarely use more than about 10% of a charge to make them live longer - and they are showing signs of living "forever" - no noticeable degradation in about 6 years so far. If anything, they act a little better than new with the new charge controllers, they seem to like that.

So the upshot is, there's a lot of up-front cost to doing it the way I do, but then, nothing for long periods. I've got panels 30 years old that are still 70% of new output. The other cost was learning to conserve, "walk lightly on the earth" which isn't really a cost after you get used to it, it kind of feels good, like you're doing the right thing.

I have never had an unplanned power failure, ever. We shut things down for about 2 min once to do some battery work. That's it - since 1979. This is the best UPS system ever!
 
DC,
Let me see if I read that right. If I want a battery system to last essentially forever, all I have to do is to size it out so that when running all my stuff all the time i only draw then 10 or 12% because I have so many batteries, they will last a hell of a lot longer?
 
My phone and bike batteries get topped off nightly, and I try to choose chemistries that can go more cycles when possible.


DC - have you looked around for a totaled Volt to pull the battery from? Maybe the insurance vultures reclaim that part already if it survived.
 
OK, every time I see the title to this thread I keep thinking you mean something like let's re-name Uranus because people always make fun of it....and then I re-read it and realize you are going in a different direction. :paperbag:
 
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Not sure what happened last night, but I lost a post here.
ancona - yes, you read right. You should size batteries so you cycle them around 10%/day.
Less than that, and with current tech, the self-discharge starts to become an issue with wasted power, and more %/day is going to shorten the life. The curve isn't quite 1/% cycle amount straight line, but up till about there, it's pretty close.

No, you can't get a totaled Volt. GM has it as a "bet the company" car, and they get them all. Not many have been wrecked at this point.
 
DC,
A lot of the facilities I demolish at the Space Center have enormous UPS units. I am talking about 750, 1000, and 2000 Kv UPS units. Two years ago we tore down the Merritt Island Tracking Station, which was equipped with one such unit. No one wanted the hardware because it was way outsized for even a small business, but there were 225 giant AGM 24 volt batteries. I sold them all for 100 dollars each, but now I am thinking I could have done something else with them, like run a cowboy system on my home with my 19 panels. Had I kept fifty of those batteries, I could probably have done exactly what you're talking about. In fact, the next system I come across I may just keep and use at the house. I have a job I am under contract to perform architectural demolition for, which involves an UPS unit about the size of two refrigerators and a stack of about forty batteries. the electrician apparently wants the system [it's being replaced for Orion] but might consider selling it to me for a few grand.

Would I be insane to put one of these monsters at my house?
 
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My experience with AGM's is not ideal. They are a lot touchier about charge/discharge than regular old flooded lead-acids - you have to treat either with kid gloves, but AGMs more so - you can't for example "equalize" those without wrecking them pretty quickly. In a big system, equalizing is a fairly important thing to be able to do. That's a controlled overcharge that accomplishes bringing the few undercharged cells in it up to full charge, while overcharging the better cells - causing some "boiling" or actually electrolytic O2/H2 generation with loss of electrolyte in the better cells.
In a normal battery - you can just add a bit of distilled water to the cells that lose it. In an AGM, well, it's "maintenance proof". AGMs are great for a rarely used system, where they spend almost all their time floating at full charge, with rare uses - most UPS systems make that (correct) assumption in the design. They are OK in cycle use, but only OK, and tend to not live as long. A UPS system is designed to "beat hard" on batteries - more of the capacity/hour is used during an outage, than a "real" solar system. That said, they'll work - they just won't live as long in that service. They are in general the design of lots of thin plates, vs a few thick ones for the same capacity, which do wear out quicker as the plates warp or are degraded and the paste falls out of them. "Real" solar batteries have fewer but more robust plates, but are designed for C/15 or so discharge rates, max (eg a 15 hour discharge cycle).

I'd carefully evaluate how good the inverter is in the UPS - there's a good chance it's not as good as the stuff I use here - in efficiency and noise, since computers (believe it or not) are in general less sensitive to waveform than many other things. You might just want to grab the batteries and build your own system otherwise. You'd still need a solar charge controller (they all have special settings for AGM above a certain quality/price level), and you'd probably rewire the battery system to some voltage your inverter and solar controllers can agree on.

My system runs 24v nominal DC. The current sweet spot is around 48v (these tend to go in increments of 6v nominal). That's where you get the most power/dollar out of the electronics going in and out. Most of these electronics are in some way ampere limited by current semiconductor tech. So at a higher voltage, you can get more watts out of the same parts - watts = volts times amps.

I'm running my panels in series strings here, so that I'm pumping about 90v or more down to the controllers, which has a switching supply to "impedance match" that to my 24v batteries, and then running a number of 24v input AC inverters off the battery pack (redundancy is good, and in my case, more efficient, since some of the inverters sit in search mode till say, an air compressor or lathe is turned on). Works great - but for the same bucks, the controllers would handle more watts per at a higher battery voltage (they are amp limited on the output), and so would the inverters - pretty much the same model other than input volts will put out say 7kw for a 48v input, vs 4kw or so for 24v - same cost, but different internals, so your inverter kind of determines what the pack volts have to be (or vice versa). AFAIK, there are not any good inverters that have changeable input voltage - you lock yourself in when you decide that and buy the model that is set for the volts of choice.

FWIW, I'm using all Xantrex stuff here, it's been very efficient and reliable. Not perfect - their proprietary version of the CAN buss they use to talk to one another and give you that nice display of system status has limits on how many things can be on it at once, and I've hit that limit here - and passed it. I have one solar controller in my system that is "on its own" which makes the aggregation of charging numbers and sync between the controllers a bit off, but I've learned to "interpret around the known system reporting errors" there - and the reason I needed so many things is that I'm using that lower end battery pack voltage...
 
DC,
Thanks for all this valuable info. When I go the battery sites, all they do is talk about how the product they peddle is the best thing since sliced bread.

That said, I have encountered every conceivable type of battery. I've seen nickle iron, AGM, lithium, NiCad......you name it. At a building I cannot name on the Cape side, they have built their own batteries. They're huge aquarium looking things with lead plates and acid. The room itself is absolutely full of them. They do X air changes an hour and have a dedicated Leibert unit to keep the room at a habitable temperature, because apparently these things produce a lot of heat. The long and short of it is that these purpose-built batteries can and do provide a huge amount of electricity. When I come across another one of these monster UPS units, i will certainly avail myself of your expertise, since you do in fact have enormous experience, having experimented with so many variations and combinations of power storage.
 
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lead plates and acid ?

not exactly groundbreaking technology )-:

just large scale I reckon.
 
They're enormous rblong, fucking huge. I would guess they are forty or more inches long, 26 - 28 inches wide and two and a half feet high.
 
There's a lot more to lead-acid than lead plates and acid, of course. The alloy of the plates matters. Cars use one, that is terrible for cycling but good for avoiding water losses - hence "maintenance free" or what I call maintenance-proof. They have utterly different characteristics than deep cycle batteries from that alone. The plates are a grid that has lead oxide or sulfate pressed into the squares, and are separated by different things also depending on design. Then there's the optimum acid concentration at full charge - varies all over the map. LA batteries, in other words, are quite complex and span a big range of capabilities.

As to ground breaking tech, that might be good in diggers, but quite a bit of experience with ni-cads, nimh, li ion (4-5 different technologies alone) - shows that it's smart to wait till something has survived the test of time. With the latter techs, there have been real serious issues with the electrodes, which instead of converting from one lead compound to another, actually have to ab and desorb metal ions, are toxic, flammable, and in some cases, not reliable. Not only that, many of them have far more "throughput losses" or larger range of voltages - for example, even the flooded ni-cads they use in locomotives have such a huge range - 50% - of volts in their normal charge range that almost nothing in the solar biz works well with them - you can't use that wide a range within a single cycle.

The above stuff is all called groundbreaking tech, or was when it was introduced. None has lasted more than a few years so far. You make that size investment in your 'stead - you want something you KNOW will last. Li-ion might take over in the end, certainly where weight matters. Vanadium redox will probably eventually take over solar - capacity only limited by "fuel tank size" and no degradation over time, but the cell separators made of nafion are super expensive.

In the Volt, to make Li-Ion work...
3 strings of 96 cells in series, then those 3 in parallel.
One thermostatically controlled cooling/heating fin per 3 cells. One relay and resistor per cell to hold back the good ones when topping off (equalizing) the pack, since overcharging Li kills it dead on one try. Over 100 microprocessors to control all this, pumps, radiators, heaters - all stuff that eats power itself, and is a reliability concern. That's the state of "ground breaking" right now.

What would you essentially bet your life on?

Ground breaking is for diggers...:rimshot:
 
DC,
That said, I have encountered every conceivable type of battery. I've seen nickle iron, AGM, lithium, NiCad......you name it. At a building I cannot name on the Cape side, they have built their own batteries. They're huge aquarium looking things with lead plates and acid.
OMG you gotta post pics of that stuff!
 
Ground breaking is for diggers...:rimshot:

gets my vote anyday

and its gotta burn diesel !

although I do sometimes ponder a kuntstler 'world made by hand' with no diggers or petrol chainsaws ............

Just how we would get the raw materials for our basic needs remains scarily elusive :flushed:
 
...yeah, chainsaw w/o petrol (electric) is a bummer.... It will either need to be carried by a horse, or otherwise, will let you half-cut one tree, on one charge :rotflmbo: For anything resembling actual "forest husbandry", I was thinking about an actual "battery pack" -i.e., a backpack, full of batteries (to the extent practical... weight), and then, a short cable to the chainsaw - which in turn, would only have motor in it, and would be lighter than even a petrol one. Although, having that thing connected via cable to a heavy battery pack on your back... kinda doesn't like the idea, either. Although my stepfather is using electric chainsaw (grid powered) around the house (because it is so much cheaper to run, than a petrol one), but you are not tied to the tool with a cable, this way.
 
Bushi,
We have [at my firm] a pretty respectable fleet of battery powered tools for interior demolition. One item is a Hilti 24v reciprocating saw. I have used it to cut logs as large as 12" in diameter and it works quite well. Hilti is one of the best power tool manufacturers I have found. their stuff is built to take abuse and for near continuous duty. If properly cared for, the batteries will last for years. I have three batteries for each hand tool, which allows me to rotate them through charge cycles during the day and keep on working. Of course after the balloon goes up, all bets are indeed off, so whatever batteries I have will likely be the last ones I'll have.

What I really want is a three foot long buck saw with a couple of replacement blades and an even longer twin handle saw for felling trees. We have thousands of Australian pines around here which grow straight and incredibly tall [for Florida anyhow]. i know of a stand close by with probably a thousand of them, with an average height of a hundred feet or more.

My primary concern is fuel for cooking and heating well down the road from SHTF.
 
I use an electric chainsaw, whenever I can, FWIW. It really sips the energy, which I can provide from various sources. One is a tiny portable generator (inverter type) that auto-throttles down when there's a low or no load and will run like that all day on a quart of gasoline.

When I can drag the tree - or major chunks of it, up close to the infrastructure, I run it on the solar system. It's a lot lighter than a gas saw, and has more torque than even the big boys. You have to be careful not to stretch the chain right off it.

This would all be practical with zero fuel should someone make an electric version of my small (but heavy and torquey) tractor to just cut a tree into 3-4 pieces and then drag them back to cut them up finer.
 
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