the smartest solar power setup i have ever seen

(I thought i had already posted this here, but i could not find it)

This is the sort of system I strongly recommend for anybody going off grid.  Normally, people get solar systems that have some huge array of panels and costs an enormous amount of money.  And then they have a HUGE battery bank, massive inverters ...  

But there was a time a few decades ago, when that sort of system would cost such a ridiculous fortune, that it was rarely tried.  Instead, when people went off grid and hooked up a solar system, they would learn some powerful lessons in how wasteful of energy they were when they were on the grid.  Suddenly, the cost of running a clothes dryer or an electric oven would be something like $2000 per year.    Soon you are drying your clothes on a clothes line and cooking on a wood cook stove. And your power needs drop to almost nothing.

Some of the most important points covered in this excellent video with Helen Atthowe:

 - two inverters.  A tiny one and a big one.  Keep them both turned off most of the time.
 - two 135 watt solar panels
 - two batteries
 - fixed panels
 - a largely DC system
 - wood heat

This is a great video!

Does anyone know what she does for hot water?

Does someone in the know have an estimate as to roughly how much a system like this might cost?

Maybe 1000?
https://www.bimblesolar.com/offgrid/12v/1040w-kit-mppt-used (too many panels, no batteries)

edit: a fast search on ebay for the individual parts:

Panels 2x260W: 300€
Inverters: 150€
200Ah @ 12V Deep cycle battery: 500€
charge controller: 50€
cables: 100€
--------------------
total: 1100€

Depends on components, like most everything you can find each part in both cheap versions and pricey versions, and lifespans on parts vary as well of course. After getting a quote for $25k to get on-grid power to my new site which has similar winter sun hours, I'll be looking for a little setup with similar needs- a few LED lights, a chest freezer converted to fridge temps, and charging of a tablet/laptop.

Initial plan to minimize fridge power needs is having it located in a pseudo-root cellar space, so (hopefully) the space itself will be cooler and reduce cooling needs.

Water heating will probably be through firewood, if the deer don't eat all my black locust sprouts! Cob Cottage Company uses a modified RMH to heat water for showers, with a water tank embedded in the mass. A small fire immediately heats the tank and within 10-15 minutes it's plenty hot for a shower. The other option is heating water as needed over a RMH already in use for space heating or a rocket stove built outside for warmer days, and mix with cold water to give yourself say 10 gallons of nicely warmed shower water or hot cooking water.

All and all that is a good system. I would change a few things though to bring it up to date or if I was putting it together today.
1) replace the small inverter with a morningstar 300 watt inverter it's standby losses are in the less than a watt range and it's pure sign. Less than $300 and she could cut out the filter which uses power.
Replace the charge controller with a more modern mppt unit. On a day like that and 270 watts of solar she should be making over 150 watt per hour with an mppt instead of 12 she mentioned. I think if you were buying new I would suggest saving the money on the dc freezer and buying an efficient ac unit and add a panel for less moneythan the sundanzer. Other than that a great minimalist system.
Cheers, David

Excellent! I love it!

I would love to have a system like that, or any working system honestly.  I have plans for one, but not a high priority yet. Good to know 1 hour of winter light gets things done with two panels. I've been thinking of replacing the fake window shutters here with solar panels since that would be an easy clean and install. I have also been curious if a system of decentralized lighting and computer/phone chargers, given the improvements in solar technology, would be worth it, and then put the rest of the house on a higher voltage system. It would allow a scalar conversion to solar, no single point of failure for everything, and less manipulating of current.

I think an important point in this video is that multiple energy sources is key, "different tools for different jobs".

As holistic planning taught me. look at all your resources- cold weather, hole in ther ground...

135 watt pv modules cost double or more per watt than 290-350 watt panels, which range from 65 cents to $1 per watt. We have had good functionality on a single 185w module... not in the winter months. Most offgrid homesteads that are not minimalist are going to require 1000-2500w solar in order to achieve reliable capacity and autonomy and useful utility.

Still, many people have had utility from a single 50 watt module and every home or use is different in some way. Good example from our system.

The well pump is 1/2 hp and is sourced from a shallow well. On paper that is 377w rough. On the meter and supplied by a single (and always on) modified square wave inverter, 2600w (maximum continuous) the actual total power is 760w running. That is inverter losses and all, maybe a phone charger or 8 watt led or two.

Judging by the still shot, our home is much like the lady in the videos home. Now, with our main array nameplate of 740w (4x185 w modules bought ten years ago at $3/watt with shipping! (Ouch.), the output might hit nameplate on some days for a short time. With the addition of 275w the output can easily be 750w for long durations on many days.

The available direct solar power is then right about at the energy draw of the pump! So no wear on batteries and storage remains full during use under full sun.

The clothes washer.... we used to hand wash all clothes and sometimes go to a laundry.
The closhes washer use requires some overlap with the well pump running, 1460w total and about 600 watt-hours. We can easily do laundry, middle of the night up to the fourth day of low sun availibility.... but we dont.

The clothes washer in winter.... in the winter or during long strings of cloudy days (michigan), i flip an array breaker that connects an additional 420w pv array. This brings available power to 1430w, nearly the max occuring demand of our entire home electrical system and appliances!

Now on any half sunny day we can do a couple loads of laundry and still have full batteries within a short time of finishing. As long as this is done by 1pm

I will do a marathon of laundry and reserve it for a sunny day and pretty much bypass the battery and have just about 1:1 direct washing until about 1pm.

Same for our electric chainsaw. 1800w, but cutting is not constant. I can cut wood and before i put every thing away and come to look at battery soc, its usually full again.

The clothes dryer...
we have a dryer it would be nice to use but it is not in our budget or need. I built a 14' tall A- frame that is a lever to tension 4, 35' long lines to hang clothes on. The other end is a cross bar, attached with a ratchet strap to a huge oak. It will hang 5 loads of laundry with about a foot of sag. Solar clothes dryer.

The winter dryer... we have stainless steel safety wires drawn dead taut in the main living area about a foot below the ceiling. Most people dont even notice it unless we have clothes or herbs hanging. These lines are stretched 16 feet across the room and infront and above the woodstove! Solar dryer.

Our wood stove heats space, heats water, dehumidifies when needed, cooks the food and dries the clothes about 7 months of the year and even though it is my slave driver, it is my favorite appliance for its utility, though i do not like to destroy or misuse the biomass. We only burn dead trees, but i still feel sorry for doing so and we are transitioning to as much solar heating as we can afford.

The actual solution should be to not live in a region where heating is required.

Another upgrade for our system is the morningstar inverter that David mentioned. I recommend it often. It is great for lighting and communications/entertainment and would allow us to turn off the large inverter most days. Our inverter requires about 300 watt hours a day to keep on.

One more thing. The price of pv modules, last season was as low as 50 cents a watt.... same panels today, 85 cents. If you are going to do this i would do it now. The price is artificially low and it will not hold. We are going to have $3/ watt costs as we use up the silver and other requirements of their manufacture. As more of the world population must resort to solar power to keep afloat, there will be rising prices to cover profit and cost.

It has to do with price controls, subsidies (theft by force again, you will be caged or killed for not submitting to cover 90% of the industrial costs before you buy!) and market manipulation. The system is a fraud and we cannot actually afford all this, it is being stolen from current and future generations and produced by varying degrees of slave labor, even in the "free world".

A gallon of gasoline has an actual cost of $25-$30 a gallon not including environmental, health, and security (theft by warfare and overt force) costs.

How much do you think a new alternator costs for your car?.... i would wager that a high quality, non slave made alternator actually costs 10-20 times at least, the $200 store tag. You cant afford it, most cannot, in actuallity afford it and if it is to be slave made and produced without care for the environment, it should not be allowed at all. That is a durable hard goods, what about tires???

The photos are a contrast between my personal system and the ones i design and build for clients.
Theirs, 8000 watt outback, 21kw diesel genset, 1100ah 48v battery, powered vent for insulated battery enclosure, cobra cables or equivalent and an 8500w array to be installed next month.

Mine, cheap but good powerbright 2600w inverter ($250modified square wave even), outback mx 60 charge controller, and a 440ah 24v battery built from high quality golf car 6 volts, no genset and about 1400w pv array 150 feet from the battery, repurposed "gang" box tool storage locker with thermosyphon vent.

Nice, timely post for me to read, as I'm about to set up my own solar set-up soon. I've been living on solar power at the school I've lived at for over 20 years, but am about to move into my own space. Both at the school and in my new place, the heat is passive solar only as well. The electrical demand is only lights, computer, phone. At the school also loud music and a TV or projector. In my new space I want a fridge (ooh, luxury!) though.

Rebecca Norman wrote: In my new space I want a fridge (ooh, luxury!) though.

Ha!

https://youtu.be/ue7wM0QC5LE

Hi, all. Paul thought I might post something here in case anyone has questions about Helen's cabin system. Sorry, I don't have any more "Quiet-tone filters" (the most common question I got from the video). I tried to disassemble it to see what was in it but it was all potted in tar.

Someone mentioned 135W panels being too expensive. Indeed they are nowadays. When we built the cabin system, they were the best price point commodity panels at the time. Now the larger panels in the ~250W range are the best value.

My goal was to keep it simple and affordable, not to power a typical American suburban home with all the same electrical convenience you get from being plugged into Grand Coulee.

Key features are:

1) Do as much with 12V DC as possible. Yes, higher DC voltages make more efficient use of wiring, but there is so much stuff you can get off the shelf that runs on 12V that that alone outweighs the possible need for more copper.  You can get 12V LED "corn" bulbs that screw into regular light bulb sockets, so you can use whatever nice-looking light fixtures and lamps you want. You might have to order them straight from China, though. You can get mini versions of most kitchen appliances that run on 12V (truck stops are a good place to buy them). The cheap, easy-to-replace inverters are all 12V. Car adapters for all your electronic gizmos are 12V. You can use a 12V car stereo in your cabin or convert a boom box to 12V, as I did for Helen. You can also get good 12V refrigerators and freezers, although the better ones also come in 24V models. When you run all this stuff on 12V, you can leave the inverter(s) off most of the time, which saves energy and eliminates fan noise. I mounted cigarette lighter sockets in deep outlet boxes and made my own cover plates by punching standard blank cover plates with a Greenlee punch. A person could also use a step drill, especially in a plastic plate. Although there is no real standard for 12V outlets yet, and the code allows 240VAC outlets to be used for 12VDC in a building where there are no 240VAC outlets actually hooked up to AC, I prefer sticking with the most standardized thing out there, and that's the old cigarette lighter outlet. By having those outlets, if your friend comes over and wants to charge their cell phone, they can just plug their car adapter in and they're good to go.

2) Set the panels steeper than the latitude-based calculations say you should. The latitude calculation is for maximum year-round energy production, which matters if you're selling into the grid. But if you're off-grid, what you really need is to maximize your production when the sun is low in the sky and the days are short.  In the summer there will be plenty anyway. Steeper also means more likely to shed snow.  Sun trackers aren't worth the complication these days, given the decreasing price of panels.

3) Use an MPPT charge controller. They not only get 30% more power out of your panels, on average, but more importantly they make the difference between charging a little bit and not charging at all on cloudy days. The cheap no-name ones you can buy direct from China off of Ebay for $100 or so seem to be okay, although of course documentation is poor.

4) If you're really strapped for cash, use whatever batteries you can find cheap or free to get started. 12V batteries connected in parallel don't have to match, although a shorted one will drag the whole set down. Flooded batteries are more forgiving than sealed batteries, as well as being cheaper. They will withstand more abuse, like over-charging, because you can "doctor" them, and add water as needed. A pair of 6V Trojan batteries is great, but an RV/Marine battery from Walmart is a lot cheaper and is a good way to start. Beyond that, old batteries in variable condition scrounged for free out of junk cars, so long as they aren't shorted, are a whole lot better than nothing, and the price is right.

5) $1000 should get you a system that's adequate for a small cabin.

David Sherman wrote:Hi, all. Paul thought I might post something here in case anyone has questions about Helen's cabin system. Sorry, I don't have any more "Quiet-tone filters" (the most common question I got from the video). I tried to disassemble it to see what was in it but it was all potted in tar.

Someone mentioned 135W panels being too expensive. Indeed they are nowadays. When we built the cabin system, they were the best price point commodity panels at the time. Now the larger panels in the ~250W range are the best value.

My goal was to keep it simple and affordable, not to power a typical American suburban home with all the same electrical convenience you get from being plugged into Grand Coulee.

Yeah, i said that! Not a critiscism though! We have much the same modules and probably just a little later than yours, when a 185w was a bigun.

The battleships that we install for people are for homes that are 4, 5, 6 people families, farms, large residential homes and supply all the homes energy, car charging, geothermal and airsource heat pump space and water heat, home mechanic and workshops, etc.  Those are in the 12-20kw range, very few 20kw residentials, usually 12-15kw for these applications.

For offgrid cabins and seasonal homes, generally we are installing about 2-6kw, the majority about 2kw.

It is a lifestyle thing. Different folks and the offgrid installs and families are my favorite to be around.
there is something drab about installing the "smart investor" system... no great homeschool kids curious and courtious, no cool animal mascots, no intent to settle in and enjoy time on the land, just accumulating and protecting wealth.

fabulous

What about hail? The western Oklahoma county I am moving to gets hail three to four times a year.

Denise, we're in South West France and several times a year, we're bombasted by extremely large hailstones during storms.



They have smashed the vacuum tubes on our solar water heaters, split polycarbonate sheets, dented our van and ruined tarpaulins covering our hay - but after almost twenty years, our photovoltaic solar panels are still intact.

People, all too often, tend to set up a solar system - then try to sort out what they can run off it. Rather than doing that, it is best to determine what sort of loads you wish to power from the system, and make your calculations for batteries, controller, and panels, accordingly.

Calculate how large of a battery bank you need to run a given load (watts) for a given length of time (hours) and total your watthours. If using FLA (Flooded Lead Acid), AGM (Advanced Glass Mat) or other sealed batteries, make sure they will not be depleted more than 50%.

From there, you can calculate the the appropriately sized solar panel array to keep the batteries charged. After that, you can determine what size controller you need. MPPT (Maximum Power Point Tracking) controllers are more efficient than the old technology PWM (Pulse Width Modulation) controllers. But, they are also considerably more expensive. Personally, I would NEVER buy Chinese made garbage controllers. I have personally tested a number of them. I would never let them determine the charge going into my very costly set of deep cycle batteries. But, that is an individual choice to make.

Do not do it the other way around, or you will end up costing yourself unnecessary expense.

Well i have a med scale system iv only just got up and running i have yet to work out some of the kinks but since we just moved in its a slow start anyway im running a custom lithium 5kw batt with 6 48v 350w solar cells and 1 500w 48v windmill  
They cost ....
Solar  pannels were about 2300$ after shipping
Batt was 7500$ "the biggest part" also has built.in solar controller/ inverter and bluetooth monitor
Windmill 250 with brake controller + 250 ish for home made colapsable tower
I will likely add a nother windmill on the same tower and 6 more pannels next year but its getting the job done now  also i have a back up propain genrator i will need it less and less as i perfect the system

Keep in mind i would have cost.me 8 grand to have on grid power run out to me
Also my old on grid house had 18 solar cells on it  

So my system was about 10 grand and after i finish it likely it will total 13k  
This system runns everything  quite well i do have to trim the fat on my energy use like no dryer and a mass heater rather then a normal furnace witch i do have as a back up i just cant run it on blast all day . I run all led lights it even runs my well pump with takes 220 as im on a hill and my well is 270ft deep  it also runs all my power tools ... I have a metric butt ton of tools lol like a highschool wood shop and auto shop and a metal shop all rolled into 1 lol  in the winter its very crappy sun here so i do need to keep an eye in it  and  i got rid of my normal fridge for a chest style fridge/ freezer. I like to add that lithium batts are sssooo much easyer  mine is tiny and on casters so easy to move around / work on however it is not light  at 270lbs still far easyer to deal with then a room full on acid batt  and safer to have in a living space    the only reason i wish to expand the system is for crappy sun in The  winter  

if you're looking for the cheapest and most simplistic setup I used in my RV a 500 watt lithium battery you can get on Amazon for about 350 and a $100 100 watt solar panel or two depending on your use of it it comes with a built-in inverter so you have 3 110 outputs as well as four 12-volt DC output sand for USB outputs you can handle anything under 100 Watts and a Max input  of 120 watts you can run all your small devices laptops and even a mini freezer on it without a problem it's a good for a simple setup as it's plug-and-play

We lived for 7 years with a similar system.
305 watts of panels
4 golf cart batteries
an 800 watt inverter
several 12vdc LED bulbs
12vdc RV water pump and a water tank during the last couple of years
12vdc refrigerator - during the summer, that took up most of our power

We charged a cell phone, laptop, used a TV and DVD player which took very little power, handheld electric can opener

In summer, once the sun went down, we'd run one of those tiny 2 stroke generators from HF to run a 5,000 btu a/c unit to at least get it down around 80 degrees so we could sleep. We would just let it run until it ran dry on fuel. Later on, we also got an RV converter/charger and tied that in and also got a bigger generator that would run the charger and the a/c unit. By that time, we had phone/dsl and the cordless ph and modem/router didn't take much power. We had most everything 110vac running on a strip plug and would shut that off at night.

After 7 years the Xantrex C40 charge controller took a dump. A year later, the inverter took a dump. We have electric now and a regular fridge. The pole went in three days after the C40 died so we ran the genie for those three days. I tried to fire up the old 12vdc fridge recently and evidently it has taken a dump. The batteries are on their way out and we did good by making them last as long as we did. So basically, I have $500 worth of solar panels and to bring the entire system back to what it was, I'd have to spend about $1500-2000 and hope the panels are still good and last while. Everything costs more than it did when we first bought all this stuff.

If they could build stuff with the quality they did 40-50 years ago, the system would be a lot more sustainable and economically viable. The Xantrex C40 was said to be "bulletproof" but it was the first thing to go.

In our case, we knew we would be living off grid for some time and we have kids so we had to be able to keep milk and food. Not including the genie or fuel for it, the solar part cost $2200 and lasted 7 years so that's $314/yr which isn't bad I suppose. $26/mth and we had everything we needed to live better than most people in 1800.

The first two years we were here was two heat wave years with highs over 100 for weeks. We brought the a/c unit with us, we went through 2 of those $100 genies and then got one a little bigger for $130 and then another just like it and we didn't run the a/c during the day at all, even during the heat wave as it wouldn't have done any good. We tried it once. Probably used 1 1/2 gallons of fuel every day for 120 days and it was $3.50/gal average back then.
-
$460 for genies over 7 years and $4410 in fuel works out to about $12.00 per day for 120 days per year - $696/yr - $173/mth for the 4 months a year when a/c was used
Not very economical but life would have been miserable without it.

The fridge was a china knock off of an enkel and the inverter was Cobra brand made in china and the C40 failing was a fluke I guess as they have a good reputation

With those components being higher quality, the whole system might have made it for 10 years but making those batteries last that long is an anomaly. Seven years would be a worthy goal for batteries and if the charge controller and fridge lasted 14 years and the panels 28 years, that would be a decent set up. It would cost closer to $3000-3500 initially.

Figuring $300 initial cost:

$500 in batteries every 7 years is $2000 per 28 years
$500 in panels for 28 years
$2000 for other items every 14 years = $4000 in 28 years

$2000
$4000
$500

$6500 for 28 years total is $928 per year or $77 per month
$6500 for 28 years is 232 per year or $19 per month as per Mr Tudor's correction of my faulty math.

Yeah, electric service is still cheaper

$80/mth is about what our electric bill runs and we run a LOT more stuff now. But if you want to live somewhere where electric isn't an option or would cost $25-20k or something to bring in, the small 12vdc system works. Other than that, a generator and fuel for when the power goes out is a better deal. A $350 generator and take good care of it. Get some fuel stabilizer and rotate your fuel.

If you could do without a fridge, that would knock off $1500 each or $3000 for the 28 years unless an enkel lasts 28 years, dunno. That would bring the per month cost down quite a bit.

Just FYI, $6500 over 28 years is $232/year or $19/month. I think having a small gas powered generator to run high demand items or top off batteries during a long cloudy spell is a good balance to go with a solar system.

Mark Tudor wrote:Just FYI, $6500 over 28 years is $232/year or $19/month. I think having a small gas powered generator to run high demand items or top off batteries during a long cloudy spell is a good balance to go with a solar system.

Oops, good catch. Think I was rushing towards the end. I edited it

I was just emailing with Alan Booker about the chapter in our book where we talk about this and he brought up something interesting:

Alan Booker wrote:On the topic of inverters constantly drawing power, I would note that newer inverters as considerably better in this regard. When they don't have an AC load, they go into a super low-power standby mode where they draw almost nothing. The problem is that, in many cases, people put phantom loads on these inverters that draw just enough AC power to never allow them to go into standby. So for modern inverters it is usually the combination of the inverter and phantom loads connected to it that creates the constant drain.

I think this is the reason it's key to have the inverters on a switch. It's much easier (in my mind) to just turn off the inverter and KNOW that there is no power draw than it is to be confident that I have no phantom loads plugged in somewhere that are triggering the inverter to leave standby mode.

I've been purchasing parts for my own system, which is "fancy" compared to Helen's system but very spartan compared to the norm around my area, here's the totals so far:

4-300w PV panels (1200w total), mounts and MC4 extension: $750 total
2000w 24v inverter: $345 (seems overkill, but that Instant Pot uses 1000w)
Outback charge controller and temp sensor: $457
Lightning surge protection device, grounding rod and wiring: $135
Circuit breakers, 4AWG wire by the foot and lugs for hooking up the components: $75~
4-225AH 6v FLA used batteries with 1 year of use: $300 total
2AWG battery interconnects and 2/0 battery to power panel (overkill): $100
Maintenance gear for batteries: $30

Total: $2192 plus tax;
After possible federal rebate: $1534~

The batteries total 5.4kwh, 2.7kwh @50% DoD, and while it seems small my estimated daily power use is almost exactly 1kwh per day. So it depends on how many of those cloudy winter days there are in a row as to when I'll get near 50% DoD. For the area's estimated cloudy winter days and estimated use, 600w of panels should be enough with a larger battery bank (like 10kwh total), but I doubled the panels and went with smaller used batteries (in case I mess up and cook them) and will see how this works. The charge controller is MPPT, so I'm hoping that the extra panels will produce more power earlier and later in the day so that the batteries are topped off more often.

One of my coworkers is totally off grid and his system seems massive, I think he said he has like 80kwh of storage, and "only" has to run his generator once or twice a week because that's not enough despite our sunny location. His system is probably more along the lines of $50,000+, which was still far cheaper than having the utility run power on to his rural property. To each their own, it works for him and I'm hoping mine will work for me! Fortunately if I find my calculations were incorrect, I can expand the system later. If battery technology continues evolving I'll be ready for new ones in several years-maybe a used Tesla battery! I read those are 24v so it would be compatible, definitely lighter than FLA and if I hook it up properly and set the charge controller properly, it shouldn't even explode!  XD

That panel to battery capacity looks good mark. 1kw production to 3 to 4 ish kwhr  storages is a good ratio for lead acid. You are a little on the high side but it will allow you to direct drive some heavy loads mid day without taxing the batteries. Think of it that way. Use that instant pot to cook at lunch time, coast morning and evening. I think you are right and There should be a good supply of used tesla lithium in a few years as the packs age and are not quite good enough for the road but plenty good for home use. I imagine the aftermarket will have 24 volt BMS retrofits for tesla packs soon. If not I would suggest l16 size surrettes/rolls for 10 more years...
Cheers,  David

The future is here baby!

http://store.evtv.me/proddetail.php?prod=TeslaBattModule

That is neat... at one third the price of a simpliphi battery. I was looking at BMS systems just this morning. Not too bad about 100 for a full system with cell balancing.

Yeah I picked up the 4 used 6v FLA as I have a couple years left till I move and as this is my first solar setup if I ruin $296.40 (total for all 4 batteries) in batteries it won’t be too troubling. My window AC runs at 1060w so I thought I’d try that too as I’ll have 1200w in panels and AC use during the day would coincide with clear sunny weather. So I’ll use wanted solar radiation to combat unwanted solar radiation!

Unless newer tech drops in price, Rolls offers I think the 27p 6v model that has 5000 cycles at 50% and over 7000 cycles at 20% DoD for something like 700-900ah. So 4 of those beasts for $4k would last me a full 20 years.

This is the kind of thing I would be interested in. zFrom torn apart electric buses

https://www.kijiji.ca/v-buy-sell-other/mississauga-peel-region/lithium-ion-battery-40v-a123-anr26650m1a-used-96-cells-total/1442887502?enableSearchNavigationFlag=true