Rachel Brylawski

Very cool!
We don't have a full sawmill here, but we do have a bucksaw we use for sawing logs (for firewood and post-and-beam construction), set up with a DC motor so it can run directly off our main solar array (which also runs our pump, grain grinder, blowers, machine shop, etc.), no battery required. Makes short work of a pile of logs on a sunny day.

Here's a short video we made of our solar saw recently:

Steven Di Maira wrote:

Rachel Brylawski wrote:. (Check out this "Cabin Iron Sun" kit for $300, which includes the solar panel, NiFe battery set, lightbulbs, adapters, etc: https://livingenergylights.com/product/iron-sun-cabin-kit/)

Hi,

I looked at the link.
That Cabin Iron sun kit is actually very interesting.

For a low price it give you the opportunity to play with Nickel Iron batteries. Without the need to shell out multiple $$$$ for a big set.
Or the hassle to import a nife battery set from China. It's doable to import them yourself, but not for such a small order.

Reminds me bit to the lead acid batteries and charge controller kits you can find everywhere.

Greetings!

Exactly our thinking! Except, the nickle irons are a lot more durable and long lasting than lead acid. And important to note that the Cabin Kit is REALLY small, just 10amp/hr, a fraction of most battery sets. Not going to run an inverter, larger motors. But plenty adequate for lighting with efficient LED bulbs, along with running a small fan and charging electronics when there's been decent sun. Which is all you really need batteries for, since, there are lots of other cool ways to meet other energy needs, as folks have been pointing out in this thread (solar water and space heating, pumps or pond aerators run right off PV panels, etc.) Yey for site-specific, permaculture approaches to designing Zone 1 energy systems, rather than just thinking of it as a bulk commodity that has to be supplied from one central source. (Battery bank and/or power grid.)
:)

Brian Maverick wrote:
Ah, got it.  You are using the original type of the Edison battery design then.
https://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery

I mis-read that for the modern variation of the battery like this,
https://ironedison.com/lithium-batteries

The combination of the LiFe are becoming cheaper to make and much more plentiful as EV vehicles and other hand-held devices are using the technology.   The huge advantage is the weight.  The nickle types are HEAVY and the Lithium are lite.  

For the link you had provided, the cost is interesting.  It's too cheap.  Sure the shipping is up there, but the weight is affecting that.  My only concern is the LED bulbs; No rating if they are health safe as in 3000K (kelvin) or less.  If they are, then it's a no trainer to snag a kit or 2 for 12VDC use.

I do like the other posting here about no battery needed.  Capacitors with a voltage regulator and a resistor or two would replace a battery for all night long LED lighting.

Brian, I appreciate your response.

You are right about the weight and bulk of NiFe batteries, which would definitely be a disadvantage in mobile applications -- you're never going to find them inside a smart phone! But for stationary household use, this isn't really an issue. Lithium batteries make sense for hand-held devices. But for the larger battery capacity of an off-grid system, the cost of lithium batteries is steep, seems like overkill to me. I just followed the link you gave for LiFe batteries and whoa! That's pricey! Almost $37,000 for 100amp/hr? I guess the only comparison I have is our 100 amp/hr NiFe kit, for $2,400, less than a tenth the cost (https://livingenergylights.com/product/iron-sun-homestead-kit/)

You said these NiFe kits are "too cheap." I'm curious to hear what you mean by that. Usually I hear the opposite critique of NiFes, that they are too expensive. I can tell from your post that you know way more about the different batteries and off-grid designs available out there than I do. In all honesty I would love to hear more about what makes these kits "too cheap."

I don't know about the kelvin rating of the 12v LED light bulbs, I'll try to find out. I do know they are only 3-7 watts, and we've never had any safety issues with them in the past ten years. We had an issue with the original kind of LED bulbs we bought that they would burn out if you left them on when it's bright and shiny out (because of the unfortunate positive feedback loop with LED bulbs), but it was never dangerous, just inconvenient to have to replace them if we were careless. These newer ones can tolerate being left on during the day and voltage swings much better and are much more durable, though it's still good to turn them off during the day.
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UPDATE: I looked into the kelvin rating more and see this refers to the color of light emitted. I had interpreted your question to refer to electrical safety, but now I see you said "healthy" -- were you referring to the potential impacts of blue light? They are making LED bulbs in various color spectrums now. We tested a bunch of different 12v DC LED bulbs and found two that we were happy with. One produces bright white/blueish light and the other produces warmer yellow light. We only got a few of the latter "Neoclassic" bulbs to test them out, they don't come in the "Iron Sun" kits or a la carte yet (https://livingenergylights.com/product/iron-sun-kit-accessories/), but hopefully in the next couple months this option will be available for folks who would prefer a warmer light spectrum.

Can you explain more about this capacitor and resistors set up you referred to, which could eliminate the need for a battery altogether (at least for lighting)? Very intriguing to me. How well do you think it would hold up in a cloudy spell? What about charging electronics?

Thanks for sharing your insights.

Christopher Shepherd wrote:Hi Rachel. I use 12v for our main power supply here on our little farm.  We just went through the darkest spring in 14 years here. We have 5 different setups with a total of 2000 watts available.  We already have 12v lights, pumps, heaters, coolers, grinders, shellers, and so on.  Have you ever tried using a supper capacitor to help with the high current start up of things like motors or inverters?  I started buying caps and build them for our own use.  They make a huge difference running things.  I have a couple 58 farad at 16.2v and a few 350 farad at 16.2v.   I would like to buy a couple 20amp hour batteries and controllers.

Christopher, sounds like a cool set up, I didn't even know there were so many tools, especially heavier duty equipment like grinders and pumps, set up for 12 volts!
I'm also impressed that you build your own capacitors. I don't know much about capacitors, to be honest, because we power almost everything (our pump, refrigerator, fans/blowers for heating and cooling, machinery, fridge, etc) "daylight drive" with high voltage DC right off the solar panel. Our main array of six PV panels is divided into in two series of three, which we can switch between in parallel or series, to have either 90v/16amp or 180v/8amp, depending on what we need for a particular motor. DC motors can tolerate significant voltage swings, it's pretty miraculous, so we don't need a charge controller or electronics or anything beyond the common sense to turn it off if the load is too heavy or the light too dim (and fuses, of course, and a surge protector to protect from the frequent thunderstorms here). With high voltage DC, there also is not a start surge when starting a motor, so we don't have to worry about capacitors, never mind an inverter to convert it to AC. We do use a charge controller to protect our battery set, however, (MidNite makes good ones in our experience) since that is more sensitive. The NiFe we do have set at 12 volts, for light bulbs and charging electronics (with "car chargers"). Since these are the only uses, our 100amp/hr set is totally sufficient for the 10-12 people at our homestead.

We recently made a video walk through of our "daylight drive" systems, if you're interested: https://www.youtube.com/watch?v=N5Wk7inoIxI
There is also more detailed technical information on our website: http://livingenergyfarm.org/energy/
And the NiFe battery kits themselves and a few 12v appliances we've found compatible are here: http://livingenergylights.com
(Though it sounds like you know more about 12v appliances than we do, I would be curious to hear more specifically what equipment you've found works well at 12v!)

Best wishes to you!

Brian Maverick wrote:
I too would echo LiFe batteries as the best resource for energy storage.  But cost wise, you can take a spread sheet see how long an RV/Marine battery Deep Cycle group 27 battery would last and it's replacements vs. the LiFe (lithium-Iron) batteries.  It's almost a wash.  The real trick is, having the right balance of capacitors to the solar setup in the system. The caps would help with heavy load startups that taxi the batteries.   Taking that load off really extends the RV/Marine Gel cells battery life.

Interesting. I don't know much about capacitor size, since we don't use AC energy and don't have to worry about the start surge. To clarify, we use NiFe (nickle-iron) batteries, not lithium iron, and run our lights and charge devices with 12 volt DC electricity. (Using an "Iron Sun" kit, available here -- http://livingenergylights.com) We reduce the load on the batteries tremendously by powering everything else "daylight drive" (running the motors while the sun is shining using high voltage DC from our main PV array), not pulling the energy through an inverter and battery bank at all.

Oh, we were also trying to develop our own nickle-iron batteries, but it is pretty dang technical. Good battery technology is beyond our DIY homestead level, or at least has eluded us so far. But it would be super cool to figure out, and not have to depend on labor exploitation overseas for them. Kudos to all of you who are working on homemade solutions.

Exciting to see how many other people are using nickle iron batteries and have also experienced their strengths firsthand: durability (our set is still operating at 110% of the rated capacity after 10 years, while the lead-acid set we started with was unusable after 3 years), putting up with being drained down time and again, non-toxic (yes, you have to be careful with the KOH, but you only have to change the electrolyte ever 5-8 years).

They do cost more, but since we've found ways to greatly reduce our need for battery storage, they are still very economical for us, especially because of their durability and minimal maintenance. Using passive solar design and strawbale insulation, large water tanks, and running motors when the sun is shining using "daylight drive" direct current, we can power our homestead without needing to go through an inverter and battery bank first. We use just a 100amp/hr set for the 12 of us, for lighting and charging (with DC LED lightbulbs. I'm not sure what issues other commenters were referring to when they said the NiFe burns through DC lightbulbs and equipment because of the voltage swings. It is true that some of the earlier bulbs we had would burn out if they were left on when it was sunny and there was a lot of power coming through, but we've found better bulbs that can handle this better, though it's still important not to leave the lightbulbs on all the time, especially in the middle of a sunny day. With good design, you have plenty of natural light during these times anyhow.) I guess also if you had a big oversized PV panel attached to your batteries, maybe it would boil through a good amount of water, and be quite gassy and require watering a lot, but if you have a properly sized panel, and certainly with a small kit like we have, the off-gassing is not an issue and it only needs the water topped off once every month or two, and doesn't take much (yes, it does require you use ONLY distilled water for this, but you can get this easily and cheaply at the grocery store). I don't know about the "self-discharge" issues people describe, since we use them daily. Maybe this could be an issue if you tucked them away for years as "emergency back up," but this wouldn't be good for any battery. Considering how well they tolerate heavy cycling, I imagine they would tolerate even this better than most batteries. We have an original Edison battery from that was rusted from decades of disuse and neglect, and even that is still at 50% capacity and still usable. Also, even if they did drain down some if they were disconnected from the panels and stored away for a while, they discharge more slowly than most batteries. In fact, one of the wonders of these batteries is that when you reduce the load some, the voltage will often jump back up, even though it's nighttime and no new electricity is entering the batteries. They are truly amazing, they behave differently than any other battery, wouldn't believe it if we hadn't experienced it directly. In 2018, we had several months of pretty much constant clouds, but the batteries never ran out, the lights never turned off.

It is unfortunate that NiFe batteries got mostly pushed off the market are not more readily produced for homestead use. Not only are they expensive, but also difficult to acquire. We have been so amazed at the potential of this technology, though, for much more sustainable and viable alternatives to the grid, that we brought over a few shipments from companies in China and Ukraine and designed "Iron Sun" kits to offer simple lighting and charging systems like the one we use at Living Energy Farm. We installed 50 donated kits on the Hopi and Navajo reservations in Arizona this spring, and are now offering them for sale (along with some "daylight drive" DC components of our Zone 1 energy systems) through Living Energy Lights: http://livingenergylights.com

I realize that this is an older post, and probably too late for the original poster, but perhaps this might be an interesting possibility for others in a similar situation to consider.

We do use small, 100amp/hr set in our system, in order to have light at night and charge small electronics. It doesn't take much to electricity to power efficient LED bulbs and charge a phone/laptop (we use 12v DC "car chargers"), but as some other posters mentioned, since we need the lights precisely when the sun isn't shining, and electronics need more regulation of the charge going through them, we do need some battery storage.

For almost all of our energy needs, however, we don't use batteries at all. We run our water pump, machinery (shop tools, grain grinder, fire-wood saw, blowers and fans, etc.), and fridge (Sundanzer DDR) directly off our main 1800 watt solar array, using "daylight drive" direct current energy. By storing water in water pumps, using thermal storage with passive solar design, solar thermal panels, and strawbale insulation, we are able to provide comfortably for our needs without an expensive inverter and large battery bank.

So I would say that realistically, a small battery bank is necessary in an off-grid system, but with good passive solar design, wood backup, and daylight drive DC systems, you need very little. Nickle iron batteries are super durable, and can last for decades with very little maintenance. (Ours are still at 110% of their rated capacity after 10 years of daily use). Our 100amp/hr nickle iron battery set provides lighting and charging for 12 people in multiple buildings. For just a few people, needing to light a few rooms, maybe run a fan for a few hours at night, and charging larger electronics like laptops only when the sun is shining, you could get away with just a 10amp/hr set. (Check out this "Cabin Iron Sun" kit for $300, which includes the solar panel, NiFe battery set, lightbulbs, adapters, etc: https://livingenergylights.com/product/iron-sun-cabin-kit/)

An off-grid system is going to involve some up-front investment in the equipment, but with nickle-iron batteries for only what truly requires stored electricity, and running the rest directly off the PV panels, makes it more economical and accessible, even with a smaller budget.

Here's a video we shot recently on "How to Field Graft a Fruit Tree":    

An invaluable technique for propogating fruit and nut trees on the cheap, if you have wild volunteers, or plant seedlings/dig up root suckers for rootstock.

Hope it can be helpful to some of you! And for those of you who already do field grafting, I would be interested to hear how your approach compares, and what kinds of trees you've had success field grafting. We've done it mostly with pears and persimmons, and occasionally peaches (mainly to a peach-almond cross called "Hall's Hardy" that is better suited to the Southeastern United States than CA almond varieties), apples, plums, and mulberries.

Persimmons work great for us here in central Virginia -- all grafted onto wild American persimmons that pop up all over around here. If you have lots of wild persimmons around, you don't have to worry about pollination either. We've found that Russian varieties, which are a cross between American and Asian persimmons, do best in our region. They have the larger size and awesome flavor of Asian persimmons, with more of the cold-hardiness of the American varieties.  Rosayanka and Nikita's Gift are our favorites. They produce reliable October-December, store really well, and are super delicious -- and the trees don't have any pest or disease issues so far. Nikita's Gift will start producing fruit just a few years after grafting. Other varieties can take up to 6. We grow some varieties that produce earlier in the season as well -- the "Claypool Series" is some of the best developed American varieties -- my favorite is "H120," which I like to call "butterscotch persimmon," which produces late August-late September here. "Early Golden" is also good, according to the fruit guru here, "Proc" is the best American persimmon by far.

The peaches we have were grown from seed, and tasty enough (at least cooked/canned, which is mostly how we eat them throughout the year) that we didn't bother to graft them, but I don't see why you couldn't. At a homestead where I lived for a time in CA, they would use root suckers of their existing stone fruit trees as root stock for grafting. On a related note, someone mentioned the challenges of growing almonds in the Southeast --  we've had success with a bitter peach-almond cross called "Hall's Hardy" (eaten as an almond, not a peach) that does pretty well here in the Southeast -- it is inconsistent year to year though, like many nut trees, usually only a decent yield every 1 in 3 years.

Mulberries can be grafted onto wild mulberry trees -- we like Illinois Everbearing. We've lost some to wild temp fluctuations in spring. I think in general, it's best to overshoot, do a bunch and hope some pull through... at least when working with wild root stock you don't have a lot to lose!

We've also have some pears we've grafted along our road -- there are some ornamental varities that pop up as volunteers around here that are great candidates for grafting fruit varieties onto. You do have to take cross-pollination more into account here, making sure you graft at least two different, compatible varieties.

To be honest, I am still very "green" with working with perennials, this is just what I've gleaned from the fruit tree guru here at Living Enery Farm. Lots more information about perennial fruits and nuts, particularly most appropriate to the mid-Atlantic/Southeastern United States, in his free e-book, here: http://livingenergyfarm.org/wp-content/uploads/2019/03/fruitbook9.pdf

He also shot a video recently about field grafting (the kind of grafting used to propogate wild rootstock):    

Hope this is helpful, and wish you the best of luck!