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Would someone critique my 1000ft view plan of off-grid solar living?

beckkl

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Jun 9, 2020
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Hi everyone, boy this site is like drinking from a firehose. I love it. DIY solar checks all of the boxes of things that I love: Saving money (longterm), DIY, self-sufficiency , etc. I have a ton of thoughts rolling around, and was wondering if someone might spare a minute or two to ensure I'm not being a total idiot.

My wife and I bought 40 acres in the UP of Michigan, where I am originally from. I currently live in WI, about 4 hrs north. The property we bought is a lovely wooded parcel on a river, and we plan to eventually build a home there. I imagine a cabin, but the plans my wife has shown me are really houses. Right now, we have focused on cleaning up the land a bit, and clearing a little over an acre for some room to roam and for a 30x40 pole shed. I also plan to use this land for ground mount solar. The eventual house will be about 700ft from this location, and in a wooded area overlooking the river.

AAAANYWHO. We currently have a small 22ft camper that we have been using, which I put a 170W (160?) renogy panel and the 12V MPP all in one. I replaced the deep-cycle that came with the camper with a 100AH AGM. It is ok, but I would like at least 2 more panels.

This summer we are building a pole shed, and I would like to spend the winter/spring building a 48V battery with the 270AH cells that have become popular. I would also like to install 2-4KW of solar panels and a 3000W Growatt or MPP all-in one (or something similar).

My reasoning:
1.) I have put a deposit down on STARLINK service, and would like to have year round internet for monitoring the property. The dish alone is 100W, not including the router/camera, homeassistant box, etc.
2.) During the summer, we would like to get a non-propane fridge to run, and maybe be able to run the camper aircon during the day.
3.) This will give me some real experience with what works and what doesn't before investing on much more solar capacity for the house.
4.) If I find that the battery is more than is needed once the house is built I could use it in the house and put something smaller in the pole shed (I doubt I would run AC between the two (700ft)

Other thoughts/questions:
1.) I have so far settled on a basic unistrut+wood ground mount system, and hope to make it adjustable so I can angle it so snow cannot collect during the winter months. Maybe I'll use 3" pipe instead of wood if this damned lumber doesn't come down in price. I have read that vertical panels near snow do pretty well?
2.) Considering the used panels from santan, but money is less of a consideration that knowing they will be reliable
3.) I would like to have EVERYTHING in the eventual house be electric. I am envisioning mini-splits in bedrooms and an induction stove in the kitchen. I do not want to depend on propane delivery. We would probably do a wood stove in the living room, but that would be it. I have not sat down and figured out the actual needs, but I was wondering if anyone else just threw a ton of solar/battery capacity at the problem?
4.) Also, there is no reasonable/cheap way to bring in grid power.

Anyway, thanks for creating such a knowledge base for those just starting their journey!
 
I have not sat down and figured out the actual needs, but I was wondering if anyone else just threw a ton of solar/battery capacity at the problem?
Most of your questions can only be answered (correctly) with the info that you gather doing an energy audit.
This is where you will probably learn the most about the electrical aspect of your project.
 
Just started myself on the whole solar and battery journey, so take my advise with a grain of salt and more as thinking out loud. I also looked at starlink for a camper. The starlink dish uses a lot of power, 100Ah a day (assuming a 24V system) the inverter, camera's and router will roughly be using half that so you are looking at about 150Ah (3.6Kwh) a day. In winter you will have to add heating to the battery unless you use something like lithium titanate, they seem to be more expensive, but with no warming required, it means you can go with a smaller system then LiFePo4. Elon Musk, in an interview, mentioned they are looking at reducing the power requirements for the dish.

The next thing you need to look at is how much solar you need based on solar irradiation on the worst winter days to keep the batteries charged up. To me that seems to be the hardest and most expensive part, I would love to hear from others who do have experience on those cold winter months. Like how big should the battery be, to tie the system over on dark days between the sunny days and how much can be generated on those dark days?

If you are not on the property and you are worried about theft, the system might create a problem because some one might think it is worth stealing. I have worked in security and sadly learned that even generally honest people take things that don't belong to them when they see an opportunity.
 
Just started myself on the whole solar and battery journey, so take my advise with a grain of salt and more as thinking out loud. I also looked at starlink for a camper. The starlink dish uses a lot of power, 100Ah a day (assuming a 24V system) the inverter, camera's and router will roughly be using half that so you are looking at about 150Ah (3.6Kwh) a day. In winter you will have to add heating to the battery unless you use something like lithium titanate, they seem to be more expensive, but with no warming required, it means you can go with a smaller system then LiFePo4. Elon Musk, in an interview, mentioned they are looking at reducing the power requirements for the dish.

The next thing you need to look at is how much solar you need based on solar irradiation on the worst winter days to keep the batteries charged up. To me that seems to be the hardest and most expensive part, I would love to hear from others who do have experience on those cold winter months. Like how big should the battery be, to tie the system over on dark days between the sunny days and how much can be generated on those dark days?

If you are not on the property and you are worried about theft, the system might create a problem because some one might think it is worth stealing. I have worked in security and sadly learned that even generally honest people take things that don't belong to them when they see an opportunity.
Yeah, that is why I was looking at starting with a 270AH 48V battery. I figured and 75AH a day (and less when you consider you are getting some sun during the day?) would be enough. Also thinking of adding a fair amount of PV to start.
 
morning,

1) no matter the solars angle, in winter expect you need to clean ur panels ( dont put them all on the roof)
2) try to snipe used panels from solarfarms. usually they 3-4 years old and 50% price.
3) I reccomend not to cook with electricity, gas much more easy and a way to diversify energy.

depending on your living area 4Kw panels might be enoth to run a house but be mentally prepared
to upscale to 6Kw and maybe add a windturbine as genset.

to give an idear about numbers, my project -> https://offgridenclave.com/2020/06/14/thehappybunker/
 
I know in my area 3 hours north west of NY city it seams like some one turns off the sun after thanks giving and it Dosent come back until the last week in January .
So things solar wise are kinda bad.
I do get some sun but not enough .
If it Dosent snow and the sun is out I can reach full charge .
I have 4500 watts of solar panels
A use about 15% of my battery over night I do unplug my freezer and don’t use all the out side lights in the winter .
I can get in about 200watts an hour on a dark cloudy day but most days I get atleast some Brightness witch can give good power.
I’m going to add a second charge controller and I have 3200watt of panels to add to the system .
If my panels are covered in snow or there is low sun I just run the Honda for 11/2 / 2 hours in the morning , 2 hours of run time gives me about 3700watts .
Last winter was rough and my panels where under 3’ of snow so I ran the Honda
Every morning and on day 4/5 I gave the batterys a solid 4 hour charge .
I use about 3500 watts in 24 hours .
 
The next thing you need to look at is how much solar you need based on solar irradiation on the worst winter days to keep the batteries charged up. To me that seems to be the hardest and most expensive part, I would love to hear from others who do have experience on those cold winter months.
In general off-grid systems require a backup power source to cover for poor insolation periods, typically an ICE generator.

It's usually way cheaper than attempting to scale up battery storage and solar PV to cover for the few periods a year when the extra capacity is needed.

Some thought on the type and size of generator output is needed, considering expected duty cycles and fuel storage. If you are in an area with ethanol blended fuel is normal, then a diesel or propane generator might be a better options than petrol (gas). Propane in a tank will store for a very long time without any degradation while diesel can be safely stored for 12 months.
 
he here you go , this is a typical day at my place in January , of course it is snowing and it -5 it’s about 9am
I fired up the Honda had a cup of coffee and I plowed around the cabin and down the 2500’ drive way
You could see in the pic a slight shadow in front of the truck .
If there wasent a foot of snow over the solar panels I would be charging .
Some years I get power all year , Last year I ran my Honda every day for 10 weeks 14 hours a week so about 140 hours for the year .
I fill up 5 gallon Metal cans ( I have 5 ) and keep stabilizer in them .
I used 50 gallons of fuel last year , the year before I only used 20 gallons .
My 2800 watt Honda cost 900 bucks and I’m sure i can get 10 years out of its.9ACC4B6B-A028-4979-B4B4-FBD5A89625DB.jpeg
The fuel was cheep last year 110 bucks . And 3 oil changes .
I fill up my 5 gallon cans when I fill the truck .
I’m a diesel guy , but I just don’t see any reason to buy a 6000 $ unit and store 275 gallons of diesel fuel.
propane is nice but it expensive and I would have to find a 4x4 delivery service to get up here even on a dry summers day .
I keep the Honda in the genarator shed with the fuel .
If we are talking a bout the end of the world diesel would be my choice .
EF9DD0E0-364F-4FE3-876F-03E56EAA02DD.jpeg9ACC4B6B-A028-4979-B4B4-FBD5A89625DB.jpeg
 
I fill up 5 gallon Metal cans ( I have 5 ) and keep stabilizer in them .
I used 50 gallons of fuel last year , the year before I only used 20 gallons .
My 2800 watt Honda cost 900 bucks and I’m sure i can get 10 years out of its.
Yep, a good quality petrol generator will also last and are not that expensive. I have a Yamaha, a similar sort of build quality to the Honda - and it will last a long time. Using it is better than not using it.

Which is now where I'm at as am not using it much now I've built my off-grid battery backup (we are on grid) as replacement for the generator. So I pull it out and give it a quick run every so often just to make sure all is good, and also connect the trickle charger to keep the starter battery in good nick.

I don't have the same issue with fuel, not a lot of ethanol blend here plus I cycle our supply through that used for the ride on mower and other power equipment so it's usually pretty fresh. Where I am grass still needs cutting in the winter.
 
O boy I hate cutting grass .
All I’m growing at my place is weeds .
I don’t really have any trouble with the bad gas I have all kings of equipment I use all the time .
I just run every thing dry and put stabilsill in the fuel .
I have a weed trimmer that some one used last year and there was fuel left in it ☹️
No grid at my place
 
O boy I hate cutting grass .
You'd hate my place then! I upgraded my mower about 6 months back and mowing time has dropped from a 6 hour job to a 4 hour job. In summer it's nearly a twice a week job. Being a fairly hilly block of land, it takes a bit longer than the same area of flatter land might.
 
That sounds bad , I’m not sure how the grass gets cut at home .
It dosent really grow very fast so I think it gets cut once a month , some one cut it over the weekend for the first time .
I think it happens 6 times a year .
The kids broke the mower 2 years ago .
 
Maybe little late to comment, but LFP batteries cannot be charged below 32F. In the UP, you'll certainly get below freezing, maybe straight through the winter. Maybe that means different battery type, or a heated structure.
 
Maybe little late to comment, but LFP batteries cannot be charged below 32F. In the UP, you'll certainly get below freezing, maybe straight through the winter. Maybe that means different battery type, or a heated structure.
I am assuming I will need to heat the battery. Since the original posting I am now also looking at the newer bi-facial cells that Will reviewed. They seem to be nice. I know you can do things cheaper with the used cells, But I do like the idea of a smaller/denser array. $2K plus shipping for 8KW of solar seems very reasonable.

I certainly understand the logic in using gas/propane etc for heat. But I REALLY want to avoid this if at all possible. My pie-in-the-sky goal is to build a cabin with electric mini-split units, even if I have to fill 1/2 acre with solar. Again, this could all be naivete on my part.
 
If you want electric heat via solar, you'll need to deal with enough battery to pull you through an extended period of overcast skies. Around here (Iowa) that can be 2-3 weeks straight. And/or enough solar panels to oversize the array. I get between 5-20% panel output on overcast skies, so it is doable. Tightly seal the battery enclosure so no air leakage and do a good job of insulating. Then you will need to make the whole thing rodent-proof, since the warm enclosure will be a magnet to all critters.
 
You are going to burn fuel no matter what ?
If your panels are snow covered you will be running a genarator until they melt off .
I heat with wood but have 1300 sf of radiant heat in my 4” slab on the first floor That I will fire with a propane water heater .
 
For the UP, you'll want to tilt your panels up to nearly vertical, i.e. 75 degrees or so, just guessing. Snow shouldn't accumulate too much. I had mine at 60 degrees all winter and snow sluffed off within a day without intervention.
 
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