14.4 KW solar, 40.96 kWh backup, 2 solark 15k inverters, off grid family home, doable or delusional?

[Themillpondhouse]

We live in South Louisiana, but are planning to build a house in North Louisiana on owned property, if we choose to sell our current house. There is a lot of development coming up where we are at, and we don’t like it. We received a great offer on our house from a developer because we have highway facing property that is right off of an interstate exit. The offer is roughly 4x what we paid for our house so it’s appealing. It is enough that by the end of it we would be able to build mortgage free, with a new build, with money left over, if we utilize the land we already own.



However due to the current housing market, it is hard to find a place we like, with enough acreage, in our budget, in our state, without having to remodel many things, with a shop for our business, without having to mortgage some of it.



Pretty much, housing market horrendous, rate horrendous, it makes more sense to build.



The alternative of not selling and us staying will result in us staring at a truck stop being slapped up across the street on the newly rezoned land. and behind us will eventually be converted from farm land to industrial. So our land up north is looking pretty good right now from that standpoint.



Here’s the big kicker after all my copious amounts of research; It would have to be entirely off grid which is not normally done in this area. Zoning is outside city limit, so off grid is permitted, no restrictions. Called a couple of local Solar companies and they either aren’t in service anymore, or they only do grid tied. Im having trouble measuring the scope of this.



There is a lot of resistance against renewable energy in our state thanks to Jindal (governor a few years back vehemently against Solar) along with the state thriving pretty heavily on the oil and gas industry. It is not embraced.



We had the electrical engineer come out and assess our property a couple of weeks ago. Cost to run electrical to property would be upwards of $60,000, not including cost to clear the lane for electrical or removal of canopy. Also would have to gain easements from surrounding timber company land owners, which will probably not happen, or will come with hefty price in addition to.





Comparable acreage in this area is upwards of $100k and not easy to plan on it being available 6 months later (due to a long due diligence period with developer) so It is worth it for us to pay for an ample Solar setup on the property we already have. I think it would be less costly to do that, than to buy a plot to build on that already has utilities.



We are a five person family; me, my husband, 3 kids. Not looking to do the whole tiny house thing. Not getting EV vehicles in the future.



So here’s the scope of what we are planning to build

Modern farmhouse 3 bedroom 2 bath main floor
2570 sq ft heated/cooled living space

Also,
416 sq ft bonus living area upstairs over the garage with a bathroom (will not be used much)

2x4 framing, Spray insulation. Orient house with long sides North and South. Front Door will be facing south.



Location is in North west Louisiana area, Approx 25 acres is ours. Flanked by additional 66 acres that is also family owned (uncle) on one side, and paper mill timber land on the other. It is on a private gated road so very private and secluded, yet about 10-15 minutes to nearest town. Outside of city limits.



Water will have to be well. Well company said between 80-280 feet is the norm for the area. I’m not sure what that translates to pump size, but can source that if needed. I know the water pumps can be taxing on the load.



Septic- aerobic w/ sprinkler.



HVAC- we think that the MrCool universal heat pump split system up flow/horizontal 4 to 5 ton 18 SEER (ducted) would be best option for us. I will say I am having trouble trying to discern how much of a load this puts on a system. I know it would be better than the traditional central AC setup. I also know that mini splits are less taxing than this, but they are ugly as sin and this seems like the happy medium.



Other things that would use power( and not all at once but regular/usual usage:

The usual light situation for a house that size (led bulbs, being mindful to have no Edison or funky stuff)

TV (multiple, kids)

Starlink internet

Garage doors (2)

Ceiling fans (at least 4)

Cove security system

Laptop, electronics, cell phones charging

Kids game devices

Range hood with vent

New Dishwasher (energystar)

New Full size refrigerator without fancy screens etc (energystar)

Electric dryer (energy star)

Electric washer (energystar, the current one we have is top loading)

Garbage disposal

Microwave

Oven part of gas range is electric



Note on dryer: will be switching to gas when this one dies. It’s about 5 years old, Samsung.



We may go new with washer and dryer to get ones that are better suited for our solar setup.



Occasionally I use an air fryer, blender, bread machine, rice cooker, toaster, standing mixer, etc. rarely use the coffee pot because we like French press but we have one of those too. Of course not all at once.



Estimating we need at least a Propane tank 500 gal



Propane appliances:

Tankless gas hot water heater

36 inch ILVE gas range (electric convection oven)

Vented gas fireplace insert



Also Generac dual fuel 18kw w/ standby switch whole home generator, I think this would be ample size for the house/solar backup.



Other details; our current usage is extremely high due to living in a 1937 home with basically no insulation and it is drafty. South Louisiana has also been quite a bit hotter than the north this year. Also older appliance usage, older air conditioning units, along with a shop that we run our business out of on current property(lots of power tool usage) makes estimating off of our current usage extremely innacurate.



If we build, then our business would be located separately from residence and in the town.



A comparable usage would be my inlaw’s house in the same area as we are building. Highest month usage is August, with 39.4 KWh a day/ 1144 kWh a month. Their house is about 2300 sq ft and they have older appliances, at least a 3 ton AC unit that is older as well, not very rationing with lights or televisions, and they use space heaters like crazy in the winter. I believe that August is the most taxing due to having to cool so much for it also is our hottest month.



So about what we think we need:



I found this on shop Solar kits website.



14.4kW Solar Power System - 2 x Sol-Ark 15K's + [38-40.9kWh Lithium Battery Bank] + 36 x 400W Solar Panels | Complete Solar Power System | [HDK-MAX]



We are looking at this, with the 2 x Sol-Ark 15K inverter option and the 8 x EG4-LL - 40.96kWh / Server Rack Battery - 5-10 Year Warranty option.



This is a complete kit that seems to fit within the parameters of our needs but I am not sure if it will be hefty enough. There’s just not enough data I have found out there of people doing something like this on this scale truly off grid.



It’s at 57kWh a day which is oversized for the current usage estimate I am going off of.



Also 40kWh of backup means roughly a day of backup on the heaviest days which sounds a little spooky. I’m hoping that the generator will cover this a bit when needed. In-laws are about 15 min away so if a bad week happens then we have a place to go to keep the system at minimum.



It is easily expandable to up to 44 additional 400w panels, and 8 x power walls (batteries?), along with an additional inverter if needed to increase output.



So if this system struggles, we have ways to easily expand.



Solar array will not be roof mounted, because I don’t want hundreds of holes in my new roof. Also I read about heat from the roof impacting the panels and that just sounded bad because it gets hot here.



We will have a cleared area with ground mount. We have land to work with. Looking at a seasonal tilt vs the fixed option.



Altogether this would run about $50k. We aren’t batting an eye at that because it’s less than what it would cost for entergy to run a line if that is even an option (easement issue). That’s the kit with the options we want, and a seasonal tilt mount. I looked for one with what seemed to be the best that’s out there and plenty of warranty.



We plan for Solar to be in a separate shed with a small mini split, or in the room in the garage (but cooled). Leaning towards shed, because room in garage is less than 4 ft wide and I would rather not have batteries in my house.



It would be a DIY install which also makes me a little nervous. It comes with schematics and everything you need to get the system up and running. The best alternative I have found is a man from Lafayette with a local solar business that said I am looking at about $120k upwards for a truly off grid system that can keep up, with him traveling and installing it. A few others I have called only due grid tie.



My husband has a few years of electrical experience as a journeyman, but not with solar. He is familiar with industrial installations as well and very mechanical savvy. He feels pretty confident in the install. He also thinks I am crazy and overthinking this. I think for new build construction permitting in our area, a licensed electrician may have to make the final connections or inspect the system (our builder is willing to help us figure this out).

 

[Themillpondhouse]

If I did it right, PVwatts says 20,049 kWh a year with the lowest months being November/February with a monthly range of 1200-1350 kWh



In north west Louisiana, the summers are hot and oppressive; the winters are short, cold, and wet; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 38°F to 93°F and is rarely below 25°F or above 99°F.

We get about 214 days of sun, 114 of those are partly sunny, and 100 of full sun.


State sunlight rank 18/50

Average Annual Sunlight Hours: 2600 hours

Clear Days: 101 days per year

Summer Peak Sun Hours: 5.71 hours per day

Winter Peak Sun Hours: 3.63 hours per day

Average Peak Sun Hours 4.92 hours per day
Not many seem to be doing this path. I’m sure most of it is that there is usually no need to do so here. We would have funding to do all of this and have some left over, I just want to be sure I have the true scope of things. We are not power hogs but we are also not necessarily a prepper family or wanting to do this for simplistic or rustic living. We like our modern comforts and also given the area, keeping cool in the hot days. I would be able to balance and manage loads to not run everything at once.

Also during most week days, we would be gone from the house until the evening due to work/school. Our shop will be located at inlaw’s house and the kids would come home to there until we would go home for the evening. So the usage load during this time would be minimal, other than putting appliances on timers to get day loads done while we are out.

Am I missing anything? Am I out of touch? What else am I not thinking of?

If you made it through this essay, I commend you. Thanks in advance for any advice.

 

[1201]

If you're going to be in a well, look for a solution that has a low surge. Like the grundfos pumps.

I wouldn't get Mr cool units. Get a regular mini split and a $120 vacuum pump and gauge kit. That way you can shorten the lines as needed

 

[Mattb4]

We live in South Louisiana, but are planning to build a house in North Louisiana on owned property, if we choose to sell our current house. There is a lot of development coming up where we are at, and we don’t like it. We received a great offer on our house from a developer because we have highway facing property that is right off of an interstate exit. The offer is roughly 4x what we paid for our house so it’s appealing. It is enough that by the end of it we would be able to build mortgage free, with a new build, with money left over, if we utilize the land we already own.



However due to the current housing market, it is hard to find a place we like, with enough acreage, in our budget, in our state, without having to remodel many things, with a shop for our business, without having to mortgage some of it.



Pretty much, housing market horrendous, rate horrendous, it makes more sense to build.

The first major issue with selling a place you live in and moving to undeveloped land is having a place to live while developing that land. There is no present services there. This adds a great deal of difficulty with simple things getting accomplished. It is not just no electricity but there are other amenities that do not exist. Having bought and developed homes twice now over my life on remote parcels of property I can say that it is not for the faint of heart and it may be too much for a family with children to do.

It also is going to cost more than you can imagine if you have never developed land from raw to homestead.

 

[Themillpondhouse]

The first major issue with selling a place you live in and moving to undeveloped land is having a place to live while developing that land. There is no present services there. This adds a great deal of difficulty with simple things getting accomplished. It is not just no electricity but there are other amenities that do not exist. Having bought and developed homes twice now over my life on remote parcels of property I can say that it is not for the faint of heart and it may be too much for a family with children to do.

It also is going to cost more than you can imagine if you have never developed land from raw to homestead.

I’ve gotten quotes for every utility we would need, quotes for building house with accounting fora cushion over budget of about 25%, along with quotes for gravel drive, house pad, dirt work, clearing of land, you name it, I’ve gotten it. It all fits well within our funding with a good amount of room for error and unexpected costs.

This is more of a case of owned landlocked property than a true off grid rural location. It is our hunting property that we would like to make into a homesite. Civilization is about 10 minutes away.

The only thing that is somewhat iffy is the solar aspect. Is this going to be enough power or should I account for more?

We also have a solid place to live while building that is within an 15 minute drive, and we know our builder pretty well so I feel like his estimate is very solid.

 

[Quattrohead]

Your potential new home sounds very similar to the one I am building in Florida, except I went with ICF for hurricane resistance as well as insulation.
You might be OK with 1 inverter but should probably plan on 2 paired together, the 14kw of panels sounds fine but I would bump the battery up to 100kwh.
Any fully variable speed HVAC will be good, I choose an ACIQ 3 ton system, hybrid HWT.
BTW putting the panels on the roof is a good idea, they will shade the roof and actually cool themselves with natural convection under them.
Mounting systems from Ironridge are 100% water proof and I am sure self build you will be more careful with this.

 

[Themillpondhouse]

Your potential new home sounds very similar to the one I am building in Florida, except I went with ICF for hurricane resistance as well as insulation.
You might be OK with 1 inverter but should probably plan on 2 paired together, the 14kw of panels sounds fine but I would bump the battery up to 100kwh.
Any fully variable speed HVAC will be good, I choose an ACIQ 3 ton system, hybrid HWT.

The kit comes with 2 inverters with ability to easily add one more. I was also thinking more on battery but I also know you need enough panels to keep additional battery tanked.

 

[pvgirl]

4-5 tons is probably over sized for around 3000 sqft, a load calculation such manual J or similar(such as the free: https://www.loadcalc.net ) will determine what the actual load for your home. For most home layouts a ducted system is going to be the best option, either a traditional air handler, or a ceiling concealed slim duct unit. A propane Direct-Vent Wall Furnace that doesn't require electricity is a common last resort heat source for off grid homes.

 

[BentleyJ]

Since you have obviously already put a great deal of thought into the project. My first recommendation would be to simply take the list of appliances noted above and put those on a spreadsheet and assign some electrical consumption estimates. At the very least 2 columns, Peak kW demand and daily KWh energy needs.

Having Propane is a big plus for sure and the dual fuel generator is nice in case there are Propane shortages and you need extra electricity to heat water and cook. (assuming the other gen fuel is gasoline)

I recently did a quickie electrical audit of an all electric rental house I own in the desert region of So. Cal. Was a bit surprised to find the potential electrical peak demand was 34kW. On course not all the appliances would be on at the same time. On the other hand, our primary residence with Nat Gas appliances has never exceeded 6kW even with summer A/C running.

Based on your post, seems like your new residence is somewhere in the middle. I believe the kit you propose would be a comfortable choice to begin with.
1) Absolutely agree with the decision for ground mount. This way you are not limited on solar PV due to roof space. Would recommend oversizing the conduit between the PV array and the inverter location so additional panels and parallel wiring can be added easily. Ideally you pull in the extra wire at the beginning.
2) Consider building a well pump/pressure tank house/shed large enough for the generator, inverter and batteries. Generator in a separate section with ventilation.

 

[superchachi]

My 2 cents.

prioritize air sealing the house. Put more budget toward air sealing and insulation...the kind that you can spray.

We live in central texas...similar in many ways...just not as much humidity as y'all get. Manual J calcs are nice, but they are not worth much unless you have a tight house in my experience. There is a reason most HVAC contractors still like using their rules of thumb...because the south gets really, really hot and humid. And like most energy efficiency ratings, they like to use averages. That is great, but it doesn't help you at the margin...when it is really hot and really cold. Don't get me wrong, I just did a full manual J calc for our house remodel...but, it is only as good as the input. The beauty of the ACIQ hybrid ducted deals is that you get the benefit of the variable speed stuff (so you can "oversize" and cool your house on the hottest days) and also be able to heat your house with electricity when the temps outside are below 34 degrees (which we see every February here). Our current heat pump won't run in near freezing temps...toaster oven heat anyone?

Based on real data from our house (using Emporia energy monitors), our A/C accounted for 75% of our electricity this summer. We have a propane on-demand hot water unit, but have electric everything else. A/C, oven/range, dryer are the big users. The Goulds well pumps (lift and pressure pumps) are not big users for us...and we are pumping 350' to the surface). Our dryer and induction range (newer units E-star) use 5-7.5kw when they are going.

Normally we are 50-60kwh/day in the non-ridiculous weather months and 120-130kwh/day when it is hot.

We sealed the attic with 5-6" of open cell (yes, not perfectly "sealed" yet...we have plans for exterior roof work) and it made a fairly significant difference over last year. Not only did we use ~15-20kwh less electricity, the a/c was able to cycle (as it is supposed to) on the hottest days.

We are remodeling and will be air sealing the walls all-around the house, adding some exterior foam as well.

The goal is to flatten our energy usage year round as much as possible to be able to "predict" running autonomously.

 

[NC_hydro]

If I was embarking on this project I would get dual Victron Quattro 10,000VA’s and go with at least 4 if not 6 15kw, 304Ah Trophy batteries. You’re off grid and will have a well, Low Frequency inverter is the way to go. If not Victron, then a Schneider, Outback or SMA. Check out current connected they have some kits you could do and add batteries from Trophy. Trophy is in SC so you could pickup in person and save some shipping. You seem like someone that would like everything to just work after setup, getting a good Tier1 LF inverter is worth the extra.

 

[Zwy]

For the new well, use an inverter Grundfos pump. When my well pump needs replacing, I will use an inverter pump. I can power the current pump just fine but if my wife has many loads running at once, I could see where an overload on the inverters could occur at pump startup.

As for a Sol Ark system, I'd look at what Ian has in a package deal and just add more battery and one more 15K. https://watts247.com/product/ul-lis...o4-batteries-pallet-17kw-550w-bluesun-panels/ Add in a Sinclair ground mount and you will be under the $50K if you do the work yourself.

 

[Quattrohead]

Low frequency inverters are on their way out along with AC motors, everything is being replaced with DC drives slowly but surely and for very good reason too. AC motors have served us well, they were very clever and efficient when new a hundred years ago but now they are hopelessly inefficient and inadequate. Just like horses got replaced with cars lol.

 

[Quattrohead]

Can the solark and sok batteries be fully controlled by a small simple RSD button?
For a new build the fire department is still going to want a simple one step process to kill power to the whole house and this is achievable now with the EG4 18k and it's paired battery or the newest LL rack batteries. Hit the little RSD button and the whole lot shuts down. Easy peasy. I have just had plans approved with this system.

 

[GuyG]

Cost to run electrical to property would be upwards of $60,000

Keep in mind that under the Inflation Reduction Act, putting $60,000 toward an off-grid solar system will give you a 30% tax credit. Seems like a no-brainer to go with Solar instead of paying Entergy 60 grand for the privilege of paying them an ongoing monthly power bill and suffering through their outages.

For off-grid I’d recommend at least 60 KWH in batteries, maybe more. You could build four 15 KWH batteries yourself for about $10,000, or buy them off the shelf for $15-20 K. Those costs likewise get you the IRA tax credit.

Good luck. Keep us posted.

 

[Pericon]

Just a couple of notes. I have a similar situation in Florida but although we have Electric Utility service we will be going Off-grid or Grid backup in the near future.

Our 3/4 HP well pump pulls about 10.5 amps at 120 volts.

We installed a 48,000 BTU Mini-Spilt system in our 2,100 sq ft home and it was the best thing I've ever done. I agree the Wall units are butt-ugly so we instead opted for 2 ceiling cassettes and 2 Ducted units all serviced by I single 48,00 BTU condenser unit. The cassettes were installed in common rooms kitchen & dinning area, the 2 ducted units served the 2 bedroom areas, each with 2 bedrooms and a bath. The effect was having a completely zoned system that very rarely operated at full capacity. Most days we would run just the kitchen area and on hot days over the summer we occasionally ran the living area. Bedrooms as needed. Hot water, oven/range and dryer all run on LP gas. All lighting is LED. I'm not at the property as I write this so I can't give you exact spec on energy usage but I can tell you that the electric bill averaged $105 dollars/month for the past year. This includes power used by a small "gatehouse" building we have near the front road entrance which has lights, a separate well pump, window AC unit and refrigerator. The only thing I would change about the AC system would be to install 2 24,000 BTU outdoor units instead of the massive 48,000 unit simply because of redundancy. I installed the system myself but did hire a local AC guy to connect the lines, vacuum pump and check out the installation. I would not use Mr. Cool on this type project.

 

[Pericon]

The total cost of the Mini-Split system including all components, duct work, small amount of electrical and including the cost of 2 AC service tech visits was about $11,000. But I did all the labor. The equipment company I used was Pioneer.

 

[Doggydogworld]

Yes, it's doable. And you're gathering the right data.
Start with an energy audit. This page explains the basics and has a link to a handy spreadsheet. The audit helps pin down your total energy use as well as your maximum instantaneous power needs. Both are important.

Heating and A/C will probably dominate your energy consumption, so you want to nail those down as much as possible.

If I did it right, PVwatts says 20,049 kWh a year with the lowest months being November/February with a monthly range of 1200-1350 kWh
We get about 214 days of sun, 114 of those are partly sunny, and 100 of full sun.

That's good data for sizing the solar array, but you need daily variation data to size the battery. Unfortunately it's hard to find good daily solar output data. A neighbor with 10 years of daily solar panel production data would be ideal, but sounds unlikely in your case. You do have relatives there, though. If nothing else, mount a panel on their land this month and collect one winter's worth of data. If 3-5 day cold, cloudy stretches are common you'll want more battery and/or a way to heat the whole house with propane.

Cloudy stretches in summer aren't as big a deal, because clouds greatly reduce A/C consumption. But clouds in winter increase heating needs. So it's a double whammy -- less solar production just when you need more heat. A backup propane heater sounds like a good idea (maybe the fireplace insert is enough?). A way to route waste heat from the generator into the house during winter would be even slicker.

You're wise to consider expansion. You can start with a minimum system and just run the generator more often the first year. Then use that data to decide if you need to expand the array, the batteries or both.

Reliability and serviceability are key. If something breaks you must be able to fix it quickly. You want a vendor who picks up the phone and has parts in stock vs. having to order them from China. Look into redundancy. Dual MPPTs, inverters, etc. are great if you can reconfigure them and limp along on a single unit when necessary.

Also during most week days, we would be gone from the house until the evening due to work/school. Our shop will be located at inlaw’s house and the kids would come home to there until we would go home for the evening. So the usage load during this time would be minimal, other than putting appliances on timers to get day loads done while we are out.

This could help a lot with A/C in the summer. It also gave me a screwball idea. You could get an EV with bi-directional charging, charge it up at the shop during the day then use it to supplement your home battery at night. You're paying 13-14k for a 40 kWh home battery. You can find 2019 Nissan Leafs with 62 kWh batteries for not much more than that. They make great 2nd cars for commuting and errands (200+ mile range). And they can save you $1000++ a year on fuel.

Look into geothermal heat pumps. They cost more, but might save money on the solar side of your budget. Especially since you have to drill a well anyway.

I recommend a radiant barrier in the roof and maybe some walls to reduce A/C load. Your contractor may already have that in the plans. South facing windows with solar screens or shutters can reduce your winter heating load without adding much to A/C load. Thermal mass can help you punch through a couple day cold snap. Big slab, brick exterior, etc. Or an indoor pool, ha! Thermal mass also lets you "pre-cool" the house directly from solar during the day then let it "coast" at night instead of running all night on battery.

 

[redalertdt]

Your in the ballpark. I would up the batteries if possible. 100kwh is comfortable and only running generator during winter time (2-3 months).

I'm at 12kw solar and 100kwh batteries and need a bit more solar. No gas appliances though, but high efficiency electric appliances, and a pellet stove and generator in the winter.

Not sure sizing for the Solark, but it sounds about right to me.

 

[KauaiMolokai]

Hi Millpondhouse,
Congratulations. You can definitely do this. Check out Engineer775 on youtube and see if he'll help you. You will get dozens of different, sometimes conflicting, opinions as you research this. If you're interested in importing various components direct from China, send me a private message - you click or hover on my name and start conversation. This can save you a lot on components. In any case, go for it. It will be a learning curve and not without challenges, but you'll do it!!

 

[ksmithaz1]

2 cents:

I'd get three (3) 240v/50a inverters in parallel such as the EG4 or Sol-Ark Units, purely for demand/redudancy. The EG4 units currently do not support staying on when one is down. If the Sol-Ark's do that is a consideration verify that part of the operation. By the time your project gets going this may change. You'll want 90 KWH of batteries, and around 20KW of Solar panels. I would design a small-ish outbuilding to hold all the solar/battery/electrical and a 10KW generator. Run 2/0 feed wires in conduit up to a 150A "sub"-panel on the house. Build high-efficiency as you have outlined. Leave room /plumb for another 60KWH of batteries in your outbuilding ( 5 equipment racks ), and another AIO (These beasts are pretty big). Get your propane but feed it to the generator. I'd run a pellet stove(s) inside for emergency / aesthetic heating Maybe in the L/R and Bonus Room, or perhaps LR and garage) or a wood fireplace if it gets too cold for a modern heat pump.

You may need to bump your solar panels for battery fill considerations, cover the roof figure out a ground-mount location for some extra as needed. I'd go all-electric appliances, including the dryer and an electric traditional 50Gal tank style HWH, and an induction range. As far as the Low vs High Frequency my pair of EG4's seem to work just fine starting a crappy Goodman 4T HVAC with a Magic Start. It worked without the Magic Start but really dimmed the lights, so HF should be fine if you engineer for it from the get go. The well pump will be the trickiest but I don't think it pulls as much on start as my HVAC did when it was 120 outside this July and no magic start. You might look into a smart electrical panel at the house.

Don't over-think it. You can also build it lower and scale it, just plumb for the extra. You could start with 2 inverters, and 60K of batteries maybe 10K of panels, and see how it goes. You can add panels if the batteries are not getting charged on lower production days, add a rack of batteries if your overnites start kicking on the generator too often.

Sounds fun, good luck. I finally kicked the grid habit a week ago with an additional 30KWH of batteries (see my sig) But I do HAVE the grid if I need it.

 

[Tamooj]

We live in South Louisiana, but are planning to build a house in North Louisiana on owned property, if...

This is very similar to our setup, (we're in East Texas) so here's some thoughts to consider. Your mileage may vary.

1. Go with a dual fuel hvac. Heat pumps/inverters are amazingly efficient but suck when it gets below 35°. Also, if it's cloudy for a few days they will drain your batteries fast. Whereas propane heat as the backup only needs the 400W blower.

2. We have 36kwH of storage and I'd double it if i could.

3. If you're going with a pedestal consider getting a two axis tracker. That basically adds 35-45% to our PV production, and we've never regretted it.

4. Get a system you can monitor and control locally (ie when there is an internet outage).

5. Your batteries will need to be protected against heat and cold, which means good insulation and a minisplit. I used a shed for the inverters+batteries, which I've had to upgrade several times to keep the batteries healthy. On the plus side it's a great place to keep plants during the winter - just add a growlight and timer.

6. Geek out on monitoring: Nothing sucks more than the lights suddenly going out on a cold day and wondering why.
We have dual SolArk inverters and wired them to a local device that displays power usage and state of battery charge on colored LED lights in the kitchen (and a graph on our phones) This lets us yell at the kids when they run the dryer when it's cloudy or at night.

7. Consider a smart electric panel which lets you turn on/off circuits as needed.

Good luck!

 

[ksmithaz1]

We have dual SolArk inverters and wired them to a local device that displays power usage and state of battery charge on colored LED lights in the kitchen (and a graph on our phones) This lets us yell at the kids when they run the dryer when it's cloudy or at night.

I considered this, and may need to revisit this summer on the weekends. Was this a commercial device or something you home brewed? I'd love to have a red-light/green-light setup in the laundry. It's so darn sunny here in the desert it's rare to have to go more than a day without significant sunshine, but the electric load in the summer is just brutal, and I'm not sure 60KWH is going to make it thru the night unless it's 100% at 1700. It's this or another 30KWH of batteries, or perhaps just lock up the little woman... She pulled a "one more load" at 1800 yesterday after I charged the car. Pulled the batteries down to 11% before solar started to help out. Not a problem this time of year.

 

[wheisenburg]

A few things:

1. Consider going with 2*6 construction on the outside walls. This allows for nearly twice as much insolation. The extra money you spend there will be more than made up for by not having to build as big of a solar / battery system.
2. Switching to a gas drier now will also save you money. The additional inverter power / battery needed to run a power hungry electric drier is more expensive than getting a new gas drier.
3. You might consider Schneider inverters. Even though they might have a lower watt rating, their ability to handle surges and out of balance loads means it is nearly impossible to trip these offline. On my system the three 100 amp batteries will trip before the inverters. If you are running large motors for your well and air conditioners, the Schneiders will easily handle the required surge current. You should get a soft starter for your A/C units in any case. The Schneiders are very reliable as far as the hardware. The software works fairly well for off grid. Some of the features like grid sell are difficult to setup, but not relevant to you. Their PDP panel allows the inverters to easily be stacked and wired together. Two should easily run the house you are considering.
4. With 500 gallons of propane, and the need for generator back up, spend the money required for an auto generator start system. The kind of generator permanently installed on a pad. It is perfectly acceptable to occasionally run the generator for an hour or two a day on cloudy days to charge the batteries. This will be far cheaper than adding the insane amount of batteries required to get through a week of low solar production.
5. Consider getting two smaller A/C units (2 ton) rather than one large one (4-5 ton). First it will give you some redundancy. It seems like it can take weeks now to get an A/C or furnace fixed. If one unit goes down, the other can at least keep the house livable. A couple of box fans can easily circulate air from one part of the house to another. Also it reduces the amount of startup current needed.
6. As some people mentioned, you can get ducted mini-splits that are installed in attics. One issue with some of these items is that while they are cheap, they are basically disposal. There may be no replacement parts or trained service techs available. If they quit working, you need to replace them. Often, professional HVAC people aren't going to want to work on these. They prefer to sell you the expensive high margin products that they normally deal with.

 

[ksmithaz1]

1. Switching to a gas drier now will also save you money. The additional inverter power / battery needed to run a power hungry electric drier is more expensive than getting a new gas drier.

Because the price of propane is going to be stable for the next 20 years? Or because you found a woman that doesn't throw her clothes in the dryer first thing on a cold winter morning to warm them up before putting them on?

IMNSHO if you are going solar, I'd go all the way electric and only run propane/other as a last resort. $500-$1000 for a gas appliance. $1500 for another 25A inverter to meet demand. The battery is the big deal, but even though the thing really uses juice, I'd roll it and plan for some extra battery. Panels are cheap. The idea is to not pay the Gas company or the Power company.