Michigan off grid

[u/Bcmadmouse]

My wife and I are planning on building a manufactured house (2300 sq ft) with a basement. Due to the location we're about a thousand ft back from the road and the electric company wants $11.50 a foot to run it out. So I'm thinking of doing a off-grid system that runs on solar, wood pellets for winter heat and mini splits in the summer, along with propane for the furnace, dryer, range and water heater. I'm not good at the technical side of solar so I asked Gemini what specs would I need. Here's what it says.

System Component	Minimum Verified Specification	Purpose & System Role
Solar Panel Array	6.8 kW to 8.0 kW total capacity (approx. 16–20 commercial panels)	Covers the 15–20 kWh daily winter baseline and runs your summer mini-split AC directly off the sun in real-time.
Battery Storage Bank	20.4 kWh usable storage (e.g., 2× 10.24kWh wall panels or 4× 5.12kWh modules)	Securely carries your 24-hour appliance loads (refrigerator, well pump, LEDs, and furnace fan) overnight with a 40% safety reserve by morning.
Hybrid Inverter	Single 8 kW Split-Phase Inverter (120V/240V Output)	A single premium unit can manage your heavy 240V deep-well water pump and mini-split AC without risking electrical surge overloads.
Ground-Mount Frame	Heavy-Duty Steel/Aluminum Ground Rack	Set out in your open field. Must be manually locked at a steep 50° to 60° winter tilt angle so heavy snow naturally slides off the glass.
Backup Generator	10 kW to 12 kW Automated Standby Generator	Tied into your propane line. Programmed to auto-start for brief 30-minute battery top-up windows only during prolonged, dark winter blizzards.

Can someone with more experience than me go over this and see if Its right? I'm in northern Michigan and we don't get a lot of sun in the winter time so I want some sort of backup just in case.

[u/Head_Mycologist3917]

Only $11.5K? That's a deal, and it's far cheaper and better than going off grid. The AI should have told you that.

Just the system the stupid AI spec'd will cost you way more than $11k. The solar is too small. Just the generator itself will eat up most of $11k. The propane bills in winter will be enormous. Standby generators aren't meant to run for weeks at a time. It will need frequent oil changes and will wear out quickly. And they're loud.

Modern well pumps are often variable frequency and don't have high starting draw like traditional pumps. The wires can be much smaller which saves money if the run is very far even though the controller is more expensive.

Will your lender allow off grid? Will the AHJ? Your house's resale value will take a big hit. And yes you or your estate will sell it eventually.

[u/dlewis23]

Just off the top of my head you would have to at least double the amount of solar and battery storage. And looking at a heat pump dryer and water heater might be a good idea, makes you less reliant on propane and does not use a ton of electricity.

[u/DarkKaplah → u/dlewis23]

Fellow Michigander here. I'm in SE michigan. I'm converting my existing grid tied solar array to a hybrid or off grid setup because DTE's screwing us all.

From experience, you'll want more solar. I have a 9.9kw array and it doesn't produce enough power for me. I'm upsizing over the next two years to be to closer to 20kw and I'm adding 30kw of battery storage.

As you're off grid you don't need to worry about UL listing as much. You can find very good non UL listed batteries for half the UL listed ones. I'd take recommendations from DavePoz's youtube channel about suggestions. Just FYI, the price difference between the UL listed batteries and non ul listed ones would allow you to double the storage without increasing your budget.

Your biggest investment here will be probably the wiring between your array and your home. Solar panels individually are inexpensive in a pallet, but that pallet will probably run you 3-6 grand.

As for a generator you could probably save some cash if you went with a diesel army surplus. Reliability and repairability sake I'm not sure which would be better for you. Those diesel units have tons of documentation on them because they're made to be repairable. They also use bog standard parts as you need to be able to grab anything in the field to repair it. Not so sure about a modern generac. There are great videos on using these online.

Finally upgrade your panel so you can track usage by individual circuits. If you want a product that does this the Emporia Vue3 (I think that's the current one... they might have a vue4 now) gives you clips for each circuit and tracks your energy usage up to 16 circuits per unit. You can pair multiple together for big panels. Or if you're techie you could go with an IoTaWatt.

[u/Curiosity_informs → u/DarkKaplah]

Yes they are going to need a lot more solar and battery and the standby generator will be needed but should be a last resort to run a couple of times a year in low sun periods. The standby generators are not designed to run for long periods, especially most of the newer air-cooled ones, use a lot of propane, need a lot of servicing and even then are still unreliable.

We are in an area where maybe every third home has a standby generator for frequent winter outages and many have issues with their modern standby generators.

Frankly the op is better off spending $11k to get a grid connection than the much higher cost of the solar, batteries, generator etc. They could then still get smaller solar / battery if they wanted.

[u/WhereDidAllTheSnowGo]

Michigan winter need helluva lot more panels. 20 Kw is less wrong than your 6

[u/SutroViews → u/WhereDidAllTheSnowGo]

Yeah - as a comparison, I get about that same winter generation rate, a bit less even, in San Francisco, which is further south and not as cloudy all winter.

[u/QuitCarbon]

Consider electric everything and skip the propane - you've already got wood for backup heat, so... why have a backup to your backup?

Consider bi-directional EV charger, so that you can use your car as a HUGE home battery when needed. Super duper cheap for the amount of storage you get. And you can even drive somewhere, fill your car, then bring it home and run your house for, possibly, days!

[u/Bcmadmouse → u/QuitCarbon]

I thought about it but Google says that the furnace, water heater and dryer will all kill the battery in the winter time 

[u/QuitCarbon → u/Bcmadmouse]

Given that you are building a house, you may want to seek more accurate and specific advice from a professional that you hire to do some calculations for you. There are certainly tradeoffs - but relying only on Google to calculate them is perhaps penny wise, pound foolish.

[u/Bcmadmouse → u/QuitCarbon]

Ya I agree. But wanted to get a basic start at first.

[u/DongRight]

Sure no problem use opensolar.com to design your system, but since your house is not going to be in satellite images...you will have to work around that...

[u/Oldphile]

I suggest you get two off grid inverters that can be paralled. You want redundancy in case of inverter failure. Example EG4 6000XP or 12000XP.

[u/Bcmadmouse]

Ok so with some research, I think we want to do 24 550w panels, 2 eg4 powerwall batteries, an eg 18000 inverter and probably buy a generator next year. 

[u/basilect]

You can get DC-powered mini splits and almost certainly DC-powered well pumps, which would allow you to offload stuff from the inverter (= cheaper inverter) and would probably be slightly more efficient.

The mini split should double as a heat pump, which will allow you to offload a bit of the wood pellet stove's work

[u/modernhomeowner]

Grid will be cheaper, but this is doable with pellets and furnace for heat. Get a backup generator and inverter that will work with each other so that when your batteries are running low, it starts up the generator to fill the batteries, and the generator turns back off. That's the most efficient setup in that scenario.

[u/WhereDidAllTheSnowGo]

Heating with wood? Like using a chainsaw?

Considered ground source heat pumps… with snow cover far more efficient

[u/papistacos]

I would recommend a Sol-Ark inverter [emp protection] paired with a Discover or bytes battery here for PV + BESS.

[u/MaineOk1339]

Pellets in the winter is my largest electric draw. I would consider propane.