Brad Vietje

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since Jan 15, 2013
Country boy science geek trying to grow, can, dry and store food through Permaculture and Hugelkultur.  15 Acres in northeastern VT (zone 4) with western slope, spring, stream and waterfall.  Land is 2/3 wooded, with a few old sheep pastures.  New straw bale house (2011) with recycled 160-year-old timber frame from a house that was being torn down.  Wood heat supplemented by passive solar design.  I'm also an experienced woodturner, telescope maker, and astronomy teacher.
Newbury, VT (Zone 4)
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Recent posts by Brad Vietje

Very Basic Info On Off-Grid Battery Banks:

Marine "deep cycle" batteries are adequate (and far more affordable) for many very small systems, but they are not true deep-cycle batteries, but rather a compromise between auto/truck starting batteries (give a brief, but huge pulse of power to start a cold engine), and true deep-cycle batteries (designed for a smaller load over a longer time period).

For systems powering household items like a refrigerator, furnace fan, or other larger loads, real deep-cycle batteries like Trojan T-105, or L-16H (and many other options) will work better.  These are often used in 6V units instead of 12V, though really big systems are often designed with 4V or 2V batteries, strung together to achieve 24- or 48-volts to the inverter.  BTW:  for systems larger than tiny ones, and those using AC power (inverter systems, instead of 12V DC), if you have the option to use a 24-volt inverter (or 48 volt) there are advantages in efficiency and wire costs if power needs to travel over long wires.  You have to configure your batteries to match the inverter voltage (so you might need to trade in 4 or 8 batteries at a time), but for full-time off-grid living with medium loads, there is often an advantage to this.

BUT -- to achieve the staying power of true deep-cycle batteries, you usually need to perform routine maintenance, including replacing lost water, checking specific gravity, and equalization (and venting the fumes and sopping up messy acid spills).  For a decent almost maintenance-free alternative (at much higher cost per Ah), you can consider AGM batteries (Absorbed Glass Mat).  They don't need water added, don't spill, and don't need to be vented, but you'll spend 2x as much for 1/2 the capacity to get there.  For AGM batteries, you'll need a charge controller with at least enough sophistication to have settings for the different charge rate of Gel, AGM, or flooded batteries.  Cheap-o controllers can shorten the life of some batteries, and for flooded batteries, usually don't offer an EQ charge (not needed for Gel or AGM).

I've advised most of my off-grid customers that if you live there full time, year-round, you need to get a good MPPT charge controller, and you should consider getting the messy flooded deep-cycle batteries, if you can deal with the maintenance.  If only for summer use, or a low latitude (lots of sun and not much cold) you may not get much benefit from the MPPT controller, which really earn their keep in colder conditions.    MPPT stuff:  Cold ambient temps => higher voltage from the solar array, which is converted to higher amperage at a voltage just above the battery bank for fastest charging.  Extremely useful for cold, cloudy places, where you want to get the very most out of every minute of sunlight.

Clear skies,

Brad Vietje
Newbury, VT
1 year ago
General note about micro-hydro power:

You are much, MUCH better off with a small flow and large head, than large flow and small head.  The only equipment that can tackle high flow and low head are expen$$$ive, industrial, commercial, municipal-scale plants that just don't make any sense for an off-grid application.

And -- it's all about the loads.  If you use very little juice, you have many more options.

There are low-head options for heads of 4-10 feet and relatively high flow rates, like the ES&D LH-1000, and some low-efficiency home-brew options (search Home Power for articles), but the tiny ES&D Stream Engine, Water Baby and Water Buddy are all tried & true commercial products: http://www.microhydropower.com/.

I've only helped install 2 systems (micro-hydro is all but impossible to push through permitting here in Vermont, so don't-ask-don't-tell off-grid power is about it), and both came from ES&D.  Those crafty Canadians have some really good stuff.

Clear skies,

Brad Vietje
Newbury, VT

1 year ago
NOT addressed to any particular person or post:

What we can see here -- very much like the past election cycle in the USA -- is that there is a lot of "information" out there from questionable sources, taken out of context, or just plain wrong, but strongly pushed by a group with an angle and an agenda.  The take-home lesson is that just because we see a fascinating post with really grabby graphics on social media, we still need to take the time to verify the source and validity of the information.

In one article cited, as soon as I saw reference to "massive subsidies" going to wind or solar, I knew I was reading an opinion piece written by someone with an axe to grind.  There certainly are instances of misused and maybe unwise subsidies, but since the fossil fuel industry gets the vast majority of the subsidies in the USA, not to mention the security and imperialism by the world's most powerful military (somehow always missing from those subsidy estimates!), I'd say RED HERRING to that one.

BUT, we really do need to look at not only the EROEI, but the life cycle costs and the environmental costs of making these various gizmos -- including the keyboard beneath my fingertips and the "cloud" that hosts all this information.  There are very real energy and environmental costs to all this.

There's just too much half-true or completely false click-bait out there, and you may regret having your name attached to it!

Clear skies,

Brad Vietje
Newbury, VT
1 year ago
Nice video!

Here in Northern New England, Morels are up a bit later -- usually found around mid-May to late May -- sometimes into early June. A good indicator in our area is Apple flowering -- Morels tend to be up when Apple trees are in flower. I have found them under/around Ash and Elm trees. Some people report Apple trees to be a host, but I've never found that to be true.

Here in Northern Vermont, I start to look for stands of Ash now, when there are very few leaves out. Ash trees leaf out last (except Bl. Locust, which rarely form a stand in the woods), so as the other species leaf out, you can often spot an Ash stand from a distance, when surveying a panoramic view -- they're the only ones with no leaves. Both Ash and Elm have distinctive bark and distinctive forms. Ash leaves are large and compound, so the twigs need to be strong to support them. Thus, Ash trees have no small twigs, only "fat fingers". Elm bark and the form of the trees are pretty distinctive, too, but many are dead or dying. When Am. Elm trees are clustered in the woods -- often around old cellar holes and abandoned farm sites, that's another great place to look. Here's a big tip: the pattern of White Ash bark and White Morels is really quite similar!

True Morels are not slippery or slimy; they have a very firm texture. If you find something that smells bad, it's not a morel -- some Stinkhorns have vaguely similar-looking, phallic shapes, but they are usually found later in the season, and they stink. False morels look disorganized and can be slimy, and the stem is not hollow with thin walls, like the true Morels. I saw a big bloom (flush?) of False Morels on a log landing after lots of trees were removed and the ground was covered in wood chips from all the tops/slash. 50 or more popped up the following year - haven't seen them since.

Last year we found a lot of White Morels -- 2 of them were about 10" tall! Black Morels are much less common here, and usually smaller. I'm told they are sometimes found near Aspen/Poplar trees, and a bit earlier in the season -- haven't found enough to confirm that. Maybe I just haven't learned to find them as well as their larger & easier-to-spot White Morel cousins. Unlike the West, we almost never find Morels associated with evergreens; not enough experience to know if burn sites are better than not.

I find that they can be tough to spot against the leaf litter and forest duff, but that getting your eyes down low -- close to the ground -- can help because you can see things sticking up a lot better, and get a better 3-D view of the forest floor. Remember to be careful of the $@^#%^ ticks -- they are bad, and only getting worse as our climate warms >

Safe, fun 'shrooming...

Brad Vietje
Newbury, VT
3 years ago
OOPS! Correction Time...

I thought the Bob Wells 5-part biochar series was from a workshop he held in Western Mass., but I was entirely wrong. It was done at Living Web Farms, in Mills River, NC.

Nonetheless, he gives a great deal of detail on how and why to make and use biochar. Too bad that the two main speakers are also in the business of selling biochar products, but since they give away the basic trade "secrets", they are also helping all of us on limited budgets to make our own. Many Permies will decide to make their own, while commercial farmers, strawberry growers and nursery owners might opt to buy the stuff. I'm keeping my eyes out for barrels and stovepipe to build my own retort.

As for the charcoal in the Amazon and the formation of Terra Preta, that will work -- obviously, since it is now an accepted historical fact -- but it could take a very long time to reach maximal benefit, and burning the wood in air puts more pollution into the atmosphere than burning off the gasses to make true char.. The ancient people who built up those soils may have done so for hundreds, or even thousands of years. We don't have that much time. AGW and Climate Chaos is already upon us, so I favor making clean biochar instead of charcoal since 1) we know how; 2) it's pretty easy with some tweaking; and 3) its really inexpensive, or even free if you are a good scrounger and have access to woody biomass.

4 years ago

Attempting to quote John Elliot here -- not sure I'm using the Quote function correctly:

3) When you rake leaves or trim brush, throw it in the swale and let it dry out. Then burn it (assuming you are in an area where the local fire department won't have a fit). Get a good bonfire going in the swale and let it burn down until it is mostly coals and not much flame. Like when you get ready to barbecue. Then douse it good with the hose. By not letting the fire completely burn out, what you have done is to create a lot of biochar in the swale. If you pile the brush and some pieces of scrap lumber 18-24" high, it will burn down so that you may have 3" of charcoal (biochar) in the bottom of the swale. Making biochar really reduces the volume of biomass.



UM, while I like your method of making shallow swales, I'd say that's not really biochar -- that's charcoal. By burning the wood in open air you're getting aerobic combustion, and not forcing the gasses out, burning them, while leaving the cellulose structure. Lots of CO2 and smoke released, too.

To create biochar, here's one simple way: https://www.youtube.com/watch?v=svNg5w7WY0k&index=1&list=PLCeA6DzL9P4vhMbHjDUmL2hlEPMssyL1i

This is a workshop held in Western Mass (Northfield or Colrain Elementary School??) by Bob Wells, who has a whole series of videos and pretty regularly runs workshops about enriching soil and sequestering carbon with biochar. Not the only way to go, but certainly something any of us could do on our homesteads, community gardens, etc...
4 years ago

Dave Redvalley wrote:The biggest difference is the depth of discharge (DoD) that you can achieve with these batteries. Lead acid batteries should really only be discharged to 80% max, while the NiFe's can routinely be drawn down to 20% with no damage, thus the 3 times smaller battery bank, with better performance. I do like that math by the way, I see now problem with it at all! LOL. The only reason I have a 24v system vs. 48 or 12 is that is what it was when we bought the place. I would rather spend the money on the batteries than on replacing all of the inverters and switching gear. The 24v seems to be working good for us.



Dave,

I have no doubt the NiFe batteries can take a lot of pounding, and can survive extended discharge without damage (no small feat at all!), but what you wrote is not technically true. BTW: 80% DOD and 20% SOC are actually the same thing -- these terms are inversely related.

Flooded (true) deep-cycle lead-acid batteries (like Trojan T-105, L-16, etc...) are designed to withstand a depth of discharge -- or DOD -- of up to 80%. That means a state of charge -- or SOC -- of 20%, but they should be promptly re-charged, and the longer they sit in a discharged state (below their float voltage), the more sulfation occurs. Sulfation is normal, and can be reversed if the batteries are charged soon after discharge, but the sulfate crystals become more permanent the longer they are allowed to sit on the plates. After a while, they are more or less permanent, and can lead to reduced storage capacity and premature battery "death". If you size the solar array and so your loads only discharge the batteries by 50%, the batteries will last a lot longer. Another critique of the flooded lead-acid batteries is that even though the can handle this rough treatment, the more often it happens, the sooner they die. Sealed lead-acid batteries, either AGM or VRLA, are more like what you describe. They should never go below 50% and really should stay at 70% SOC or higher (30% DOD or lower) for good battery life.

NiFe batteries can be very deeply discharged, and can be left at a low SOC for extended periods without significant damage, and that is a really big deal. They are clearly better batteries, and we do need more companies to manufacture them.

As for the question about the battery bank voltage: most inverters are more efficient at 24 volts, and even better at 48 volts. Higher battery voltage affects the way the solar panels and batteries are wired, but higher voltage systems need smaller gauge wires and smaller gauge battery cables, and smaller gauge wire means a lot less copper or aluminum. If your solar panels are a long distance from the batteries and charge controller(s), you can save a LOT on wire by designing your system to operate at higher voltage. I have a few customers with solar panels about 300' away from the house, and when voltage drop and all that are factored in, they saved about $1000 on copper wire by using a 48-volt inverter.

4 years ago
Hey Cam,

The Iron Edison batteries do look like great performers, but don't be lulled into thinking that a strong alkali is any better than a strong acid. In fact, some solar pro's are worried that the electrolyte could even be worse, since all you need to clean up a battery acid splash is baking soda. There are concerns that getting the alkaline solution in your eyes, for example, might be worse that hydrochloric acid.

The incredible long life is absolutely spot-on, though, and I agree that if there was greater demand, and more manufacturers, the price would be a lot more reasonable.

Clear skies,

Brad Vietje
Newbury, VT
4 years ago
'Nuther Safety note:

Watch the color coding on those battery cables..... People tend to rely on them for their own personal safety, so you really want them to be correct. Notice in the photo of Alivia leaning over the batteries that the nearest battery has a red-labelled cable coming off BOTH terminals One of them is lying, and if you are relying on the red/black colors to know what to touch (and what NOT to touch), you could experience the meat fuse concept. Get out the black electrical tape, and correct the red color on the (-) terminal -- or reverse the cable if it is wrong on both ends.

Also note that her right hand is fairly close to a red (presumably +) terminal.... this is where you need to be careful. If that hand moves just a wee little bit (like when struggling to reach something or loosen a bolt, etc...), and that shiny wrench touches a (-) terminal SNAP!

Clear skies,

Brad Vietje
Green Works Solar Store
Newbury, VT
4 years ago
Nice photos & great progress.

The photos of Alivia putting a wrench to the batteries in the electric cart really gave me a start, though.
HO - LEE- S#!T !!! This is MIGHTY dangerous stuff!!! Safety note for anyone reading this: Big cables on batteries are big so they can carry a lot of current. A good way to help remember this is: "the size of the fire depends on the size of the wire". Those appear to be 2-0 copper cables, which can handle 283 Amps, which is PLENTY to kill a beautiful little girl, or even a big strapping daddy. Really. Dead.

I have had off-grid customers tell me that they'd do all the battery work in order to save money, but also based on the very much mistaken idea that the 12-/24-/48-volt stuff must be easy, since the voltage was so low. I had one young customer that had a 12-volt battery bank, and a 5,000 watt inverter capable of a 8,500 watt surge. As a solar installer, I have to run the numbers and if he draws those batteries down as low as 10.7 volts when that beast surges to run his stupidly inefficient well pump, that's 8500/10.7 = 794 Amps !!! That means his cables need to be 4-0 cables doubled up. I tried to convince him to go to a 24 or 48 volt inverter and get rid of the well pump, but since his dad gave him the inverter.... Anyway, it turns out that the 120 and 240 volt AC power is MUCH safer to work with -- just look at the sizes of the wires! It's the low voltage (high amperage) stuff that can kill you. Remember: big wire => big spark.

SO -- when working with batteries:

* Wear heavy-duty rubber gloves
* Use only insulated tools -- no shiny chrome handles!
* Use a wrench that is too short to bridge the gap between + and - terminals whenever possible
* Safety glasses/goggles recommended. Batteries can explode -- though only rarely -- but if they do, the stuff you'll be sprayed with is really nasty
* Watch what your other hand is doing/touching -- don't be a "meat fuse" !
* Watch for anywhere the terminals could possibly come in contact with metal, and make sure it can not touch.
While we're on watches, don't wear one with a metal band -- or any metal jewelry on your fingers. Gold and platinum are much better conductors than human flesh, and you would not be the first to burn off a ring finger when that wedding band touches the (+) terminal
* No loose or dangling metallic objects (think glasses that won't stay on or are on a chain, bracelets, gold necklace, etc...)

Sorry to be such a wet blanket, folks, but working with batteries can be very dangerous, indeed, and you never want to touch a battery with a shiny metal tool held in a sweaty hand. It appears the photo is from a year ago, so Alivia must have survived the ordeal, but let's be sure to be really, really careful around batteries and big cables.
4 years ago