New Offgrid System with Some Luxuries

[SilverbackMP]

So I'm willing to invest quite a bit of money into a new system for my mom's house.
My parents have been running on a genset and small 12volt Trace/Outback system for close to 25 years.

I'd like to gut that and start over.

Bottom Line Up Front - Load Calculations:

Using an online load calculator, to install the new comfort of life additions, it looks like this will use 40,843 watts per day with a peak of 5878 during the summer and 23,963 watts per day with a peak of 3,939. With 3.28 Winter Sun Hours/Day, the calculator is suggesting that I build a 12.67 KW system.

Current Situation:

The heat is wood with a propane supplement. The refrigerator is propane and was on its last legs 10 years ago. The (now broken dryer) is/was gas (this doesn't necessarily have to be replaced and wasn't included in load calcs). The existing solar array is peak and feeble and she has to run her genset most days. Either to get some AC (window unit) relief in the summer or from dark and dreary days in the winter. And the current Genset is much, much too big - 30kw. So most of its power is being wasted. (I got a hell of a deal on a slightly used Ingersol Generator Trailer unit after their old generator died.)

The current inverter and deep cycle lead batteries are in the house. This will be relocated.

Comfort Improvement Plans:

I'd like to replace the propane refrigerator with a 20 cubic feet Energy Star conventional electric top freezer model. I would like to add a 20 cubic feet electric freezer. The major additions would be 3 Pioneer (Energy Star) mini-splits. One 22 BTU for the open plan downstairs (36x32 or 1152 square feet including a bathroom and utility room) where my mom also has her bed (moved it down to take care of my dad before he passed and she has no intention of moving it back). This one will stay on for a good chunk of the day in the summer. The second mini-split (9 BTU) will be installed in the room I use upstairs (the total upstairs is only 36x18) when I'm in town.

The third (9 BTU) will be installed in a 10x12 outbuilding where the new inverter(s) and batteries will be installed - both for AC and heat - so this one will run a tad bit in the winter to keep the temperatures up in the lower 50s. This outbuilding currently has a panel box that the generator feeds 110 vol power into. It sends 110-volt power to a second outbuilding (no additional) and to the house to the inverter. There is a second breaker panel in the house as well.

I plan on insulating this building and installing the inverter(s) and batteries here along with the freezer. It will also serve as a spot for long-term food storage. That 3rd mini-split will be used to keep the area conditioned for the inverter, batteries, and food.

The other catch to this is that the future panel array(s) will be a minimum of 120 feet away. Maybe further is I need to erect more than one. So I am thinking that I will need a fairly high voltage charge controller?

Systems I'm looking at:

1. Sunny Island - probably this MidNite Solar enhanced system:

MidNite Solar MNSI6048D-2CL150 Pre-Wired 12,000 Watt Sunny Island Inverter System

MidNite Solar MNSI6048D-2CL150 Pre-Wired SMA Sunny Island Inverter System Rated For 12,000 Watts

www.solar-electric.com

Pros: Beefy; simple, not as complicated as others.
Cons: Cost
Question: Would I need to swap out the MidNite Classic 150s for 200s or 250s? To allow for more voltage to cross that 120 feet+ of wire to the inverters.
Question: Is there any way to (easily) connect remote monitoring? Even if it's just to the house so my mom can check the battery charge without going out to "the shed."
(I soooo wish that I had been working on this a few years ago and got in on the liquidation deals).

2. A pair of Schneider CONEXT XW PRO 6.8kW plus Schneider or MidNite Solar Charge Controllers and bit and bobs.
Pros: Beefy; remote monitoring
Cons: Perhaps overly complicated.

3. Growatt 12k
Pros: Most plug-in play, low cost, remote monitoring
Cons: I don't necessarily trust it.
- But I could buy four or five of them for the costs of the other systems. I doubt I'll go this way. Perhaps for a future shop building with its own system...but I need this shit to be bulletproof for my mom.

- The other option that I was considering was 2x Outback Radians, but that might be overkill and would cost more.

Batteries:

TBD. Around 40KwH of rack-style Iron Lithiums.

Solar Panels:

TBD. Probably something like Canadian Solar 390 watts. Maybe those 310 watt used panels if they are still around in a couple of weeks. Sure would save some cash.

Racking:

Probably going to build a large, large lean-to pole barn-style carport. Something between a ground mount and roof mount with the low side being around 6 ft. It will be overbuilt. I ain't an engineer but I'm not going to skimp on something that resembles an 18 x 40 foot kite.

Other Notes:

I'm assuming that the Genset will need to be reconfigured to send 240 volts instead of 110.

Other Questions:

- Given a convention break box panel is both the outbuilding and the house, can I send 240 volts to both locations from one set of inverters and have the separate breaker boxes split them apart like a regular box would from grid power? And offer 240 volt and 110 volt in both locations?
- Can any of these systems absorb more generator power than the others? To take advantage of the current generator's power.

Electrical is not my forte and I plan on doing the grunt work and the direction of the family friend electricians.

Also, no grid power is available, and would cost around $200k to bring it in. And neither of two power companies, a mile away in either direction, seems too enthused to do it.

I've attached a layout of what the property looks like.

Been researching this shit until I'm blue in the face - it's about time to start asking questions cause I would like to install this in May.

 

[Bvillebob]

Sounds like a great system and a great thing to do. About remote monitoring, the Midnite Classics have an ethernet output, which I connect to a wireless bridge that links to my home wifi. My solar gear is about 200' from the house, so I use a longer range wifi unit in the house aimed at the shop to connect to the wifi bridge. Really simpler than it sounds at first, and it works great. I can be anywhere within 500' or so of the house and use my phone to monitor the solar, in the house I use my laptop. Great info available in the monitoring apps, I love it.

 

[MichaelK]

My vote would be for the XW Pro. I've also paired mine with a Midnight200 and they've both functioned flawlessly for years now. Make sure though that you get either the SCP or ComBox for setting changes in the XW. You will need it if you want to make changes to things like generator input.

I designed my array frames out of unistruts, and rotate East to West, so you might be able to cut your panel needs in half if Mom and Dad are willing to go out and change their directions. I found that I could basically get double the sun hours with manual tracking.

On just a regular day with just TV, lights, computer, and the frig on 24/7, I find I'm using ~3-4kWh of power. With my 5500W of panels, I can make that much in the rain.

 

[corndog]

Strange that Sunny Island page is gone just a few hours after you posted it. Here's the cached page:

MidNite Solar MNSI6048D-2CL150 Pre-Wired 12,000 Watt Sunny Island Inverter System

MidNite Solar MNSI6048D-2CL150 Pre-Wired SMA Sunny Island Inverter System Rated For 12,000 Watts

webcache.googleusercontent.com

 

[SilverbackMP]

I designed my array frames out of unistruts, and rotate East to West, so you might be able to cut your panel needs in half if Mom and Dad are willing to go out and change their directions. I found that I could basically get double the sun hours with manual tracking.

Dad is gone and mom is 66 and is getting a knee replaced in May (which is why I'll be around for about 8 weeks and can get this done). So I'm trying to make this as user-friendly as possible. I am even debating the carport idea (because of height) vs a true ground mount. But I think with a squeegee on an extended pole, it would be possible for her to clear light snow. Heavy snow? Run the generator. This is Missouri so it's likely to be ice as snow anyway. But I digress.

I might end up building a place right down the driveway overlooking that pond. But that will entail removing a ton of trees (which I hate) as it's surrounded by my grandmother's CRP land and locked in a contract. The wooded areas aren't part of the contract. Anyway, I digress again.

 

[SilverbackMP]

Sounds like a great system and a great thing to do. About remote monitoring, the Midnite Classics have an ethernet output, which I connect to a wireless bridge that links to my home wifi. My solar gear is about 200' from the house, so I use a longer range wifi unit in the house aimed at the shop to connect to the wifi bridge. Really simpler than it sounds at first, and it works great. I can be anywhere within 500' or so of the house and use my phone to monitor the solar, in the house I use my laptop. Great info available in the monitoring apps, I love it.

Great to know all of this. Thanks. What's the brand of your wifi extender if you remember off the top of your head? I'm looking for a good one of those too.

 

[SilverbackMP]

Strange that Sunny Island page is gone just a few hours after you posted it. Here's the cached page:

MidNite Solar MNSI6048D-2CL150 Pre-Wired 12,000 Watt Sunny Island Inverter System

MidNite Solar MNSI6048D-2CL150 Pre-Wired SMA Sunny Island Inverter System Rated For 12,000 Watts

webcache.googleusercontent.com

Hmmm...I wonder if that's an old offer and saw this post and they just caught that it was live? Price was exceptional considering that the base units are $3500 each new. Other folks have it listed, but it may be something that MidNite doesn't offer any more as well. The Youtube info on it was around eight, nine years old.

Midnite Solar MNSI6048D-2CL150 - Inverter Supply

Shop for Midnite Solar MNSI6048D-2CL150 at Inverter Supply for best prices online. Midnite Solar MNSI6048D-2CL150, Midnite Solar, MNSI6048D-2CL150, Dual Pre-Wired System, Midnite Installation Supplies

www.invertersupply.com

 

[Hedges]

Midnight Classic can talk to Sunny Island with an interface Midnight made.
I think it is gone from their website (because newer Sunny Island firmware invalidated it), but if you have older firmware it could be a nice addition. Ask Midnight about what versions work.
What it will do is let Sunny Island tell Midnight what voltage and charge phase.
Alternative using battery shunt doesn't give Sunny Island control, only reports current.

With Sunny Island, you ought to use Sunny Boy rather than DC charge controllers for at least some of the PV. You can use both.

You don't have to use the pretty yellow Midnight boxes. You can put AC breakers, load-shed relay, DC fuses elsewhere.

eBay and Craigslist have Sunny Islands. Here's one listing:

Complete Solar Generator Cabinet w/ QTY 2 SMA Sunny Island 6048 w/ Warranty | eBay

Find many great new & used options and get the best deals for Complete Solar Generator Cabinet w/ QTY 2 SMA Sunny Island 6048 w/ Warranty at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[SilverbackMP]

I am very tempted to go with Schneider because there's a plethora of detailed YouTube info including this channel/playlist: https://www.youtube.com/playlist?list=PLkmO_DrGWs-LgBISOOmc3YodJMtphvZun

I actually think that I could possibly get by on one inverter...even with three mini splits...especially if all three plus the pump for the cistern don't all startup at the same time.

I'm still confused about some of Sunny Island stuff despite studying this stuff intensely for two weeks (I own a business that manages itself (after years of work and investment) plus VA disability...so I have the time lol).

 

[SilverbackMP]

With Sunny Island, you ought to use Sunny Boy rather than DC charge controllers for at least some of the PV. You can use both.

I've been reading up more on Sunny Boy, and it might be the better system IF I build that shop at the bottom of my diagram. I was assuming that I might need a completely separate system for it. But I think I could get by running 240v back down from the power shed. Google Earth says it's around 210 feet which would put a line loss 1.1 % with 6 gauge at 30 Amps or 1.8% at 50 amps.

I think a complete SMA system would be more easily expanded vs the Schneider - which still doesn't seem to have the bugs of stacking even the XW Pro completely worked out.

If I were just powering the requirements that I listed above - house and power shed and AC mini-splits, a single XW pro would be fine (I think). But if I do build a workshop, I'm gonna need reliable 30 Amp 240 power to include enough for a cabinet saw and a GOOD dust collector to run at the same time (along with an additional mini split). And or a 240 volt air compressor and plasma cutter at the same time.

I think the SMA system would be easier to expand and more robust.

Opinions?

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And if I do build a place next door, I think that a SMA would also be better suited (a completely separate system here).

Besides residential, I need enough to power a business (seperate building) that might have 5-10 people working at once...including a couple of them using gaming rig equivalent computers (video editing) and a moderate sized server. An alternative here would be to build that in town four miles way. Land (non farm) is basically free lol (village with a population of 80, midwest, BFE).

My place would also eventually have an (ICF constructed) pool and hot tub...the Army destroyed my back...these would help. The pool/hot tub would eventually be covered with a pole building and slide glass panels for four season use.

I plan on a ground/pond source heat pumping for the most of the heat (including the pool and hot tub) and possibly the air conditioning.

This is if we don't hyperinflate and/or have WWIII before all of this is complete.

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Sidenote: I grew up fairly poor blue collar country and know/knew how to use my hands back in the day. Worked some construction, farm stuff, slaughter house, etc. But have been working military officer and white collar for the past 25 years, so some of those skills have dulled...but I'm hoping to revive them. I guess my point is, I'm not a complete newb when it comes to DIY, but I'm not a razor sharp as I could be either.

 

[SilverbackMP]

It's too bad that the shop isn't already constructed. Makes more sense to put the power room there for a short run from the panels to the inverter(s) and for only one run back up to the house and outbuildings with 240. But I don't think I have the time to coordinate and get all of that built (or the liquidity) to get all of that built-in 10 or so weeks. The shop would be a pole building, so the skin can go up quickly and easily. The bitch is in in the finishing. I suppose I could go ahead pour the floor and insulate and frame and finish out a power room space.

The thing is with the floor, I was also considering radiant from a pond-sourced heat pump. But a wood/mini-split option or radiant propane would also suffice and be a hell of a lot quicker/simpler.

On edit: then again, having a separate power room that's outside of a shop or home might make even better sense. A bunch of electronics and batteries with a shit ton of potential energy has an inherent fire risk no matter how up to code it is made. If that building burns, you're not out a house and a shop full of shit (including a 50 hp tractor and the future potential for a mini excavator and CTL/skid loader in my case).

 

[400bird]

For the house mini split, I'd recommend looking into a two zone mini split. When you're not home, the upstairs head unit can be turned off. It should be cheaper to buy a single, slightly larger outdoor unit and two indoor units. But, the single indoor units do get cheap. So, I might be incorrect.

I'm biased because I chose the XW, but your loads fall right into the the 6800 watts that the XW pro can handle. All the issues I've had with mine are related to my AC coupled solar. One of the members here had a single XW pro initially and it added a second one.

Also, if you currently have only a 120v line to the house, they do support 120v only output.
Each can charge up to 140 amps DC from the generator. I don't think anything is going to soak up the 30kw.
Actually, with 2 stacked XWs you could do about 13.4 kw at 240vac.
That's a huge generator!

The combox is discontinued, the current gateway thing is called an InsightHome. I'd recommend it if you want remote monitoring. If you want to walk up and make changes, you should also get the SCP. I'm pretty sure it was designed to bolt into the XW in place of the standard display.

 

[Hedges]

I like my Sunny Island/Sunny Boy system.
I put in 4x SI wired 2s2p because I got a bargain on them. This allows 112A pass-thru vs. 56A. But 2x Si wired 2s would be more reasonable.

Each SI can deliver 5.75kW continuous (at 25 degrees C), 11kW surge for 3 seconds.
While the sun shines, SB 6.0 -41 (or older models if you don't need latest grid-support features) produce up to 6kW with enough panels.
So with 2x SI + 2x SB, you get 22kW surge and up to 22kW continuous during the day. 11kW at night while the batteries hold out.
(if strictly off-grid, can have 24kW of SB. Probably better not have load go from 24kW to zero all at once; takes a few seconds to throttle back.)

Something like that could power house/shop/business pretty well.
Understand the starting surge of your motors; "LRA" if quoted on label, or 5x operating current. Battery inverter needs to supply that.
VFD will start and run a 3-phase motor without surge, but rectifier/capacitor front end makes waveforms that upset Sunny Boy. Need good PF; I'm about to try some Lambda modules before VFD which should do that. Higher end VFD with good PF should avoid the issue.

 

[SilverbackMP]

Also, if you currently have only a 120v line to the house, they do support 120v only output.

I was going to run a new 240 line for the mini-splits and for the potential to replace the water pump with 240v when it fails (but it's not a huge one, pumps up a bladder for water from an underground cistern (the top is at grade - looks/functions like a patio). Other than that, 120 volt would suffice. I can rent a 3 ton execavator for $100 a day, so the trenching part doesn't really phase me too much.

Each can charge up to 140 amps DC from the generator. I don't think anything is going to soak up the 30kw.
Actually, with 2 stacked XWs you could do about 13.4 kw at 240vac.
That's a huge generator!

Yeah, I thought about buying a smaller Kubota or Yanmar unit, but if I can make and store enough power to not run it that often, that cash is probably better suited towards more panels and batteries. The current one has a Cummins 4BT - it doesn't exactly sip fuel but it's not a hog either. And I gave just over $2k for it (4 or so years ago) with just over 1000 hours.

Might still swap out the Genset in the future though...and use it myself if I build my setup as referenced above (business, plus pool house, plus 3000 sf or so residence)...I'll likely need a larger capacity setup.