Building a home in the wilderness with this vehicle.

[outdoors]

Nice! Things like this is why when I built the system on our house 4 years ago did a minimal AGM battery bank. I figured by the time my batteries were due to replace at ~7 years there would be much better options out there.

This is the thing that has kept me from wanting to go off grid complete minus fossil fuel sources. I could never feel that the battery system was really up to what the solar was able to handle. Maybe if the truck could couple with a couple powerwalls, or have the ability to supplement in extreme use. Yet need off grid really. Plus wind?

I see the new designs for these Cyber truck houses all over instagram. Seriously doubt a truck could reverse power those places for very long. Ancillary power sources must be present.

 

[coleAK]

The adaptors or whatever to allow Lafrisbee to charge his truck from solar panels while drawing 120V power at the same time may not exist right now but I am pretty sure that in the two years before the truck is available either Elon or some aftermarket guy will come up with whatever is needed. His Cyber will probably have a 150KW battery while your solar has a 15KW. I think he will be OK.

That’s not how electricity works. Solar panels are regulated to around 15v DC and a Tesla battery is 400v DC So even if you could DC to DC couple a 15kw (~51 295w panels) solar system (like you mentioned) to the truck will not charge a 150kw battery in 10 hours under optimal conditions. In simple terms and So as it stands you have to use the 15v DC solar to charge a DC 12v battery bank then convert with an inverter to AC to charger the Tesla through the on board charger that charges the DC batteries. Even in the theoretical future when we can charge DC to DC it would require massive transformers (and batteries) to couple the solar (15v) to the 400v battery.

There is a lot of good info out there about DC micro grids and building DC wired houses to take out all the inverters.

 

[larryboy]

Do a search for Quasar. They seem to have it figured out now so I guess this is the theoretical future.

 

[SeminoleFSU]

I’ve done 5 solar systems now mostly myself. Started with a 600w on my camper then a 1.8kw off grid 12v with battery bank for our cabin finally a 7kw hybrid on/off grid with battery bank and wind on our house then helped friends with another 2 cabins. Unless you are in a few very select areas in the US (mostly high SW plateau) and have great un-obstructed sun exposure solar alone isn’t a good stand alone option. And we’ve seen nothing to say that the CT can be used as a battery bank, 220 inverter but that’s hardly the same as a battery bank. And even if you were banking on the truck as a battery bank what happens when the truck battery gets low? And it’s middle of winter? Gray and overcast for 2-3 weeks? Snow on the panels? Then what?

If for his cabin charging the truck wasn’t in the equation you could do a pretty awesome 12v DC solar system for $3-5k. If you wanted to do a system large enough to run a small AC unit as well and traditional 110 AC outlets $6-8k. If you add charging the truck and do it your self with a 6kw system your looking at $6k for the panels, $20k+ for mounting racks, wiring, conduit, breakers, , hardware +- a tracker, $500-$1k charge controller(s), $2k for an inverter, $10k for hydro electric or $10-15k+ for a wind turbine, and $20k (AGM) to $40k (Li) for a 40kwh (equivalent) battery bank. And all those figures are without paying anyone for labor.

A few things most people don’t realize about solar: first, most systems are grid tied so if the grid goes down you solar doesn't work, it’s not as easy as a transfer switch. Also for off grid functionality Even under direct sun solar (or wind) does not produce a consistent enough amp to start up any appliance or run much load so you need a battery bank large enough to support whatever you want to run/charge, basically the batteries run the electric system and the solar charges the batteries.

The more I think about it if it were me going off grid in the near future to retire to a cabin in the woods it makes way more sense to spend $10-15k up front and go on sportsman’s guide or CTD and get a cabin tent, cot, outdoor kitchen, wood stove, camp shower, water filter/system, and get a 9k generator, beater 3/4 ton truck and ATV. Then build the cabin with a super nice 12v DC system or AC system if need to run A/C and large freezer capacity, that way would be out <$20k for power system, truck, camp, ATV vs $100k+ for a CT and system to charge it.

finally @larryboy. Last November we had a 7.1 earthquake and I lost power for 2 days. Like I said I have a 7kw solar hybrid system. My battery bank is on a 2nd breaker panel that only runs the necessities: water pumps for heat, well pump, and our kitchen. Heat, water heater, stove, oven are all NG and gas didn’t go down. My battery bank is a 15kw AGM and I have it set to 80% it was cloudy/stormy and gray and with my 7kw system I made <2kw/day and on day 2 Battery was down to 20% and couldn’t overcome the load required to run the heat water pumps so had to start my 9k 220 generator (my back up to solar at the time) to recharge the batteries. Luckily shorty after we got power back. After that I also installed a wind turbine as it is almost always breezy at my house. So basically whatever size solar you think you need add another 50% and whatever size battery you think you need at least double it.

You need to look at the SolArk 12k the game has changed!

 

[coleAK]

You need to look at the SolArk 12k the game has changed!

Yes, Very similar to the inverter I have on my house:
Hybrid Inverter System - Conext XW+ 120/240V | SE Solar

And like I’ve been saying to build a complete system around the inverter you mentioned or mine, that Off grid will reliably charge a Tesla your looking at $50k+

 

[JBee]

@coleAK
Most household PV panels have open circuit voltages of over 32V, not 15V, and most decent solar inverters can handle up to 1000V DC as a input from PV panels in series. You most definitely don't need to go down to 12V DC first from solar and then back up to AC. There are also heaps of transformerless solar inverters (switchmode) . There are also a few, very affordable, stackable, off grid solar inverters ($800 for 5kW) available that let you run them without any batteries connected at all.

Ultimately, a CT will offer the off grid connectivity off the shelf, as it already has a 110V/240V inverter output and a AC charger input. You can then charge it at your local supercharger, or get one of those batteryless off grid solar inverters and charge it at 240V AC.

The battery on the CT should last the OP many days, if not weeks of battery by itself.

 

[lafrisbee]

@coleAK
Most household PV panels have open circuit voltages of over 32V, not 15V, and most decent solar inverters can handle up to 1000V DC as a input from PV panels in series. You most definitely don't need to go down to 12V DC first from solar and then back up to AC. There are also heaps of transformerless solar inverters (switchmode) . There are also a few, very affordable, stackable, off grid solar inverters ($800 for 5kW) available that let you run them without any batteries connected at all.

Ultimately, a CT will offer the off grid connectivity off the shelf, as it already has a 110V/240V inverter output and a AC charger input. You can then charge it at your local supercharger, or get one of those batteryless off grid solar inverters and charge it at 240V AC.

The battery on the CT should last the OP many days, if not weeks of battery by itself.

I agree. Especially as I am building a high-quality very tiny home.

 

[SeminoleFSU]

Yes, Very similar to the inverter I have on my house:
Hybrid Inverter System - Conext XW+ 120/240V | SE Solar

And like I’ve been saying to build a complete system around the inverter you mentioned or mine, that Off grid will reliably charge a Tesla your looking at $50k+

50k seems way high...
I got two quotes for the Solark 8k installed with a roof mounted 11kW system fully EMP hardened and a battery system big enough to provide UPS like capability on my critical loads panel. Was like $33k gross 27k after rebates.

And you might want to look at the SolArk closer. It's likely superior to what you have in a number of ways

 

[SeminoleFSU]

And you can turn the amps way down and trickle charge the car at a much lower rate you don't need a megawatt system, you just need to overcome the vampire drain + whatever you use + efficiency losses

 

[larryboy]

OK, I have given this matter some thought and here is what I would do. I would buy a generator that runs on propane. I got a 6KW one for about $500 with shipping. I would see if propane can be delivered to your site. If it can I would buy a 500 gallon tank. you can rent a tank but if you own your tank you can shop for the cheapest propane (around here, cheapest in June). They only fill a tank to 80% to allow for expansion so your tank would give you around 400 hours of run time. At 6KW per hour you could fully charge your CT 8 or more times. If your electricity use is what I think it will be, a 3 or 4 hour run once a week will keep your truck charged up. You can go for a walk at charging time and avoid the noise. I think a real handy person could put a better muffler on it as well.
Having propane on the site means that you could have a camp stove and BBQ grill.
I would also consider getting a small shipping container. The small ones are 20x8 and are not very expensive. You could haul it to your site on a flatbed trailer and offload it with a winch. This would give you a place to lock up your stuff, genny, building materials, food and also a dry place to pitch a small tent. Much nicer than living in the CT. You could spray insulation and install a couple of windows and a door and dispense with the tent. Or just prop the big door open. If the CT provides enough power you could get a small fridge and even a window A/C You could install a cheap wood stove and be warm and dry if you don't get your house finished by winter. Once your house is built it could be a shop or wood shed or guest room. I hope you keep this thread up and let us know how you do.

 

[lafrisbee]

OK, I have given this matter some thought and here is what I would do. I would buy a generator that runs on propane. I got a 6KW one for about $500 with shipping. I would see if propane can be delivered to your site. If it can I would buy a 500 gallon tank. you can rent a tank but if you own your tank you can shop for the cheapest propane (around here, cheapest in June). They only fill a tank to 80% to allow for expansion so your tank would give you around 400 hours of run time. At 6KW per hour you could fully charge your CT 8 or more times. If your electricity use is what I think it will be, a 3 or 4 hour run once a week will keep your truck charged up. You can go for a walk at charging time and avoid the noise. I think a real handy person could put a better muffler on it as well.
Having propane on the site means that you could have a camp stove and BBQ grill.
I would also consider getting a small shipping container. The small ones are 20x8 and are not very expensive. You could haul it to your site on a flatbed trailer and offload it with a winch. This would give you a place to lock up your stuff, genny, building materials, food and also a dry place to pitch a small tent. Much nicer than living in the CT. You could spray insulation and install a couple of windows and a door and dispense with the tent. Or just prop the big door open. If the CT provides enough power you could get a small fridge and even a window A/C You could install a cheap wood stove and be warm and dry if you don't get your house finished by winter. Once your house is built it could be a shop or wood shed or guest room. I hope you keep this thread up and let us know how you do.

I appreciate your thinking this through for you. But so much of what I want would go against having fossil fuel even remotely associated with the site, and waste.
As I sit I have a house full of *sugar* that I can live without. I am also engineering the very tiny home to be 10x15x10 (completely rough estimate. I'd like an even smaller footprint but I want it to have every creature comfort at a very high level...just tiny.) I may build another one even smaller if I like doing it. And that would be the guest house..or not. But I don't want to go the easy route if it lowers the standard.
of course I'll sleep in the Tesla Utility Vehicle a few times before I make a decision. Everything will remain influx for as long as it can.