Family going off-grid in a small cabin-hale.

Palanakonu

My family and I (wife and two kids) live in Hawai'i, on the south side of the Big Island. I will begin building our new home soon which is just a small place in the wooded area that we are hand clearing (in process now). We'll be using solar and water catchment. We are using our savings to buy the land (done), build our small but humble hale , provide clean/safe water, and then power - in that order. So basically it will be whatever money I have left over that will be going towards the solar and batteries. I'm estimating that it will be around $4,000 that I will have for this, but real-world has told me that it will be less. I know it is not a lot of cash to go towards it, but it is what I have and there is no possible way that grid power will ever be here.
Our actual power *needs* are not that great. We currently are energy hogs with electric hot water, electric range, and just being generally wasteful averaging 10kWh per day without paying any attention to turning things off when not in use, so I know our 'final' solar system will not need to provide this much. What I need *now* (or when the new place is built rather) is something that will power a new modern fridge (TBD), internet router (Ubituiti ER5) and camera system (Arlo Pro) 24/7. We also watch maybe two hours of television of the evening, but not on most days... TV is a 60" LED. We'll likely run a ceiling fan for about 6 hours a day, and a few LED lights of the evening.
I know we use a lot of power now, but our rental has an electric range, electric hot water, and an old fridge. Our new place will have LPG for the range and OD hot water as well as a new fridge, and since we'll be going off-grid I'll keep that in mind when purchasing.
We want to get moved into the new place as soon as we can, that will allow us $1700/mo (from not paying rent and electric) to go towards upgrading what we skimp on at first.

With the solar, I am hoping I can get *just* what I need to run the fridge, internet, cameras, and a few lights at first, and then grow the system as funds allow. This would allow us to find that perfect spot of energy use for us.

Now, I am figuring that a 48v solar system is pretty much a must, or at least the best idea. So I was thinking that if I went ahead and got say.... an Outback FM80 CC, that would work now and allow me to grow without replacing it.
Panels are expensive here but can be had for a-buck-a-watt in most cases. I can always keep adding panels.
Costco has 6v golfcart batteries that I could use at first until my system grows.
Something like the Cotek SP1500-148 inverter would work for now, but I could save for a good Outback inverter.

I'm still learning about solar as time permits. I'm never afraid to admit my ignorance though, or ask for help when needed. So I'm coming to you guys for input. I'd like to type more here but I tend to ramble and I see I have done just that, so I guess anything further I'll add as additional comments. Have to go now anyhow. So please, does anyone have any suggestions or insight here?

Palanakonu

Ahh yes, forgot to mention.
I already have a 3kW inverter genset to use for additional power in charging the batteries, or running the clothes washer when needed (we line dry clothes here).
Figured I'd put that bit of info in here before heading out.

mike95490

Wow. That's going to be a big change.   I concur, that a 48V system for a family is going to be a necessity.  The ability to power a microwave for 2 minutes, or a toaster for 3 (my wife HAS to have toast, real toast, not pan toast, or broiler toast) is very important.

What structure will house the batteries, controller, inverter and generator ?   If it's in the house, you want quiet gear, not fan cooled stuff.

You need power specs for your stuff, the fridge and any 24/7 appliances (router @ 20w x 24 h = 480wh, half of what a fridge uses)

If using an inverter genset, MAKE SURE it can power your desired charger.  Some cannot handle the odd power factor or load a charger or inverter/charger presents.

westbranch

Just about diner time so short reply.

Look into Solar tube water heaters. you can start with black plastic water pipe and get started, get pressure rated, not thin wall. need DHW tank, electric, can do double duty later when PV installed. Use Excess after batteries well into Absorb.
Yes , you know you are going to expand PV arrays, OK to start with a good big CC, don't expect a lot from the GC batts, like all loads on...  be kind and it will give reasonable service.
Check prices on mainland and cost of shipping, friend has a place on one of the small islands there and he even shipped windows from CA. Be aware of delays ...
Buy all the panels you can afford in one lot as chances are they will probably disappear right after you buy./..  maybe do a layaway type plan with supplier...??
Your estimate of initial loads is actually fairly large...  check out each appliance or cell charger etc... you may be surprised.  Constant small loads add up when on 24/7
If you keep under 3000Kwh per day , 24 V could handle it with bigger inverter...  see which loads ,Cell, can be powered DC direct or from a step down converter.
details details details.... It took us 2 yrs of planning and writing it all down.  Use lowest consumption appliances, forget the bells and whistles... like ice cube maker... make spreadsheets, for each rooms  consumption...
Jobs not done till the paperwork is finished...


hth

mcgivor

Educating your family to conserve will be a challenge, old habits die hard, at least that was my experience.The refrigerator usually is the highest demand, look for the most energy efficient, even better with inverter technology to avoid inrush. As mentioned above planning is critical, avoid being too conservative when estimating, consider losses such as inverter self consumption, panel and battery efficiency and so forth. Plan the location of the array especially with regards to shadowing and the seasonal change of shadows.

Marc Kurth

Just a quick comment: I agree that shipping costs should be looked at closely. 

In my experience, 12 to 15 day freight shipments to the islands are not as expensive as some folks seem to think.
Literally this week Monday, I sent an 850 lb. pallet delivered to downtown Honolulu for $248.
In February I sent a 960 lb. pallet to the dock in Kapaa, Kauai for $255.  These are just two examples.

Shop your suppliers! 

Marc

Palanakonu

mike95490 it's not going to be as big of a change as you think. We have only been using power like this for the last 7 months or so. Before that we lived in a little 'jungalo' and used half of what we do now, because it wasn't available.

As with most things, when you have it in excess, you tend to waste.

Fortunately for us we don't use a toaster, or a microwave, or a coffee maker... or a slew of other things that people find necesary for every day life. Truth is, we barely spend time 'inside' the house during the day time hours. Way too much to do and too much friends and ohana to live our lives indoors.

westbranch: Solar tube heaters, batch water heater, and all sort of make-shift water heating devices are quite normal on the Big Island. I actually plan on a batch heater for the outdoor shower, and to *preheat* the water a bit before entering into the on-demand heater.

mcgivor believe it or not but these are fairly 'new' habbits. So dropping them should be fairly easy. I grew up without electricity. We used a generator to keep a freezer going, but that was about it until I was a teenager and the farm got full time (albeit not very stable) electric.

I am not kidding myself, I know that we will *use* power, that's a given. At least we never relied upon it for heating and cooling like you mainlanders (and a lot of places on the islands here) have to. I just want to start with what is necessary to keep the fridge, internet, and camera system going, but not have to completely start over when I get the cash-on-hand to upgrade. So I'm wandering what I should and should not avoid. I have learned quite a bit, and know I will learn more. But I haven't the experiences with brands and the quirks of these systems like you guys do.

I'm hoping to hear from someone in the same shoes here telling me of their experiences, or someone saying that it either is or is not feasible to do what I am wanting. Anyone care to say, "OK, here is exactly what you need to do!" ?
Not necessarily wanting any hand holding, but I'm sure my wife will look the other way if someone does.

mcgivor

In a nutshell if it heats or cools it consumes large amounts of energy, unfortunately a refrigerator is generally a must have appliance which often governs the size of a system if all other loads are small or intermittent. My approach was to build a system strictly for the refrigerator, it is an inverter type refrigerator which allows the use of a smaller DC-AC inverter with sleep mode, they have no inrush current associated with regular units.  ( see link for explanation )

Washing clothes, pumping water and cooking with a crock pot are all done using excess power late in the absorption during sunny days. It is amazing how little energy you really need after sundown, beware of those small loads on all night, best if they're turned off when sleeping.

Of course what you are planning can be done but without details of loads, others cannot make  suggestions with any accuracy, if you were to provide a list, that would be extremely helpful.


https://news.samsung.com/global/how-the-digital-inverter-compressor-has-transformed-the-modern-refrigerator

Palanakonu

mcgivor: I have been gathering information with my Kill-a-watt for the last week. I have it hooked up for 24hrs on each device so that I can get a more accurate estimation of power usage. I'll update here when I have it.
The fridge will be the only complete guesswork here, as I'll just have to see what is available and pull info from the manufacturer and hope it is close.
I forgot about the catchment pump, so I'm glad you brought that up. I'll have to see what the best route on that will be.

Dave Angelini

Start small on the refrigerator. You can get a bigger model later. Bring your meter to store and ask them to let you run it for an hour
on a floor model. The GE's are nice small 15 to 18 Cuft models. Last year my distributor had a wherehouse in the Islands. The budget is too low so you will have to do this in baby steps. If you are in the hills, use gravity for water/rainfall. The 24V battery choice suggested may be the only way to make this work. They will be cheaper to replace down the road. Good Luck!

BB.

I would start planning with a 3,300 WH (3.3 kWH) per day or ~100 kWH per month system. That is enough to (generally) run a full size refrigerator, water pump, washing machine, LED lighting, and TV/Computer (LED / low power type). A very efficient home.

Use a 24 volt battery bank as a starting poiint:

• 3,300 WH per day * 1/24 volt battery bank * 1/0.85 AC inverter eff * 2 days storage * 1/0.50 max discharge = 647 AH @ 24 volt battery bank...

That would be 4x 6 volt @ ~220 AH golf cart batteries in series * 3 parallel strings for a 24 volt @ 660 AH battery bank (12 batteries total). On the main land, a GC battery is ~$100 each and will last you 3-5 years (conservative but realistic estimate).

Get a ~1,500-2,000 Watt AC inverter @ 24 volts.

Solar array--5% to 13% rate of charge recommended for solar. With 10% or higher rate of charge for full time off grid system (especially when you have day time loads too).

• 660 AH * 29.0 volts charging * 1/0.77 panel+controller derating * 0.05 rate of charge = 1,243 Watt array minimum (weekend/seasonal usage)
  
• 660 AH * 29.0 volts charging * 1/0.77 panel+controller derating * 0.10 rate of charge = 2,486 Watt array nominal
  
• 660 AH * 29.0 volts charging * 1/0.77 panel+controller derating * 0.13 rate of charge = 3,231 Watt array "cost effective maximum"

And also need to figure out array based on the amount of sun you receive per day:
http://www.solarelectricityhandbook.com/solar-irradiance.html

Hilo
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 70° angle from vertical:
(For best year-round performance)

Jan	Feb	Mar	Apr	May	Jun
5.45	5.82	6.08	6.25	6.23	6.76
Jul	Aug	Sep	Oct	Nov	Dec
6.72	6.33	6.22	5.79	5.32	5.08

Lots of sun--use 5.08 hours (long term December average hours of sun per day) and fixed array:

• 3,300 WH * 1/0.52 off grid system eff * 1/5.08 hours of sun = 1,249 Watt array minimum (December "break even" month)
  

So--I would suggest a 2,486 Watt array system minimum which would give you a nominal:

• 2,486 Watt array * 0.52 AC off grid system system eff * 5.08 hours December sun = 6,567 WH per day (December) nominal
  

That is a very capable system. That size battery bank (660 AH @ 24 volts) would support upwards of a ~3,300 Watt AC inverter (~500 Watt inverter per 100 AH @ 24 volt battery bank) and a maximum array of ~3,300 Watts (to large of an array can overheat batteries when charging).

A 2,486 Watt array would need a minimum MPPT charge controller of:

• 2,486 Watt array * 0.77 panel+controller derating * 1/29 volt battery charging = 66 Amp minimum rated solar charge controller
  

On growing a system... It is not easy. It is sort of like buying a VW Bug, growing it into a pickup. Then into a diesel 18 wheeler... Not really going to happen.

Some issues:

• I suggest a maximum of ~800 AH for a battery bank... If you have 800 AH @ 12 volts, you can change to a 400 AH @ 24 volt or 200 AH @ 48 volt (same energy storage).

Continued on next post:

BB.

Picking a bank voltage--There are the rules of thumbs for how much continuous and surge current you can get from the bank... But sometimes you also would like to use DC appliances too (HAM Radios, RV/Marine water pumps, etc.). 12 volts and 24 volt devices are pretty common. 48 VDC is pretty far and few between. Using your AC inverter to power your pumps and stuff is usually easier than trying to run a 12 volt or 24 volt sub system with a higher voltage battery bank (can be done, but just more things to buy and maintain).

Solar panels--You can add them--But sometimes you run into issues with trying to buy "matching" panels (Vmp/Imp) 2-3 years down the road, and "your old panels" are no longer available. You can run into issues trying to make a single solar array out of mix and match panels (or just get a second charge controller with the "new" array/panels).

The MPPT solar charge controllers can run nicely at 12/24/48 volts--So they can be migrated to a higher voltage battery bank very nicely.

AC inverters--You are stuck at the voltage you bought. Got a 24 volt inverter, you need a new 48 volt inverter to upgrade battery bank voltage. One thing with AC inverters, it is very easy to buy a very big inverter but your battery bank will not really support those higher wattage loads (that rule of ~1,000 Watt AC inverter per 100 AH @ 48 volt battery bank). Flooded cell lead acid batteries have limited surge current (i.e., 100 AH # 48 volt battery bank will support ~2x current to start a well pump on AC inverter). Mostly, once you size the battery bank for storage (i.e., 3,300 WH per day, 2 days storage, 50% maximum discharge)--It usually will also support your loads (peak, starting surges) unless you have very different energy needs (existing 240 VAC deep well pump vs buying a new "solar friendly" water pump for ~$2,000 to $3,000 just for the pump). Also, check the "tare" current/power of the AC inverter--Getting too big of AC inverter, your inverter could take 20-40 watts or more just to "turn on" before your first loads. A "right sized" inverter will waste less energy (your refrigerator will "average" around 60 Watts of power--A too big inverter can use as much energy as your refrigerator).

Battery banks--I suggest that you do not want to add new batteries 3 years down the road to an "older" battery bank. You will probably be fighting "battery issues" for years until you replace all of them at once. And regarding Golf Cart Batteries--They are cheap and relatively rugged units. Great for a starting bank where you are learning how to manage and maintain your system. Many people "murder" their first battery bank or two until everyone learns the limitations. Plus, if you "goofed" on sizing your power needs, you are out much less money if you need to drastically modify the bank down the road. Long term, I would suggest (for example) 2 volt @ ~600 AH cells (12x 2 volt cells in series for a 24 volt @ 600 AH battery bank). You only have once set of cables and 12 cells to check vs (in the above system) 3x parallel strings and 36 cells to check specific gravity/electrolyte levels in.

In general batteries are expensive and have a limited life--And are easy to kill with improper maintenance/usage. You want to size the battery bank to the loads--If you do not know your loads--It is difficult to design an optimum battery bank. Everything else is designed to keep the battery bank "happy" (solar array sizing, AC inverter sizing, backup genset+battery charger, etc.).

Once you have a paper design for your approximate system sizing (like above)--Then you can start looking for hardware that will meet your needs.

Just remember, you are now the "power company" and have do your own maintenance and fix/buy replacements. Batteries will last typically 3-8 years, electronics (chargers, AC inverters) will last ~10+ years. And solar arrays ~20+ years. Your system may last longer or shorter--Just want to make sure you have money in the bank to fix your system--Nothing like trying to limp by on a crippled system or running out your credit card (I recommend you avoid carrying credit in general for daily living expenses).

Anyway--A starting point.

-Bill

jonr

> Bring your meter to store and ask them to let you run it for an hour on a floor model.

Various issues with doing this properly - I'd just use the rating sticker, maybe adding 25% for a warm climate.

Palanakonu

BB thank you for a thorough and somewhat confusing set of replies. I understand *most* of what you are saying, I'll figure out the rest as I re-read it, over and over and....

From what I am gathering now, and looking at the budget I have for this, I believe I might be better off starting with the smallest system I can that will just run the bare minimum (fridge, lights, pump), and then saving about $8k for the final system. Then either selling the smaller system or keeping it on hand in case I need to take the main one down completely for maintenance or some other unforeseen circumstance.
As for your last comment - we are one of those fortunate families that do not have debt (credit card or otherwise). People often ask how we can live in Hawai'i with such a limited income (by Hawaiian standards)... it's because we own everything we have and owe no one. It's nice to wake up and feel that kind of freedom.

Any input on the idea I had above? Just a small 24v system to power a fridge and such, with the genset to run the washer of course, then getting a whole new system 6 months to a year later?
I know it might sound outrageous to people used to having a television and 3 computers on all day and night, but around here that kind of stuff is just.... strange - except for the bad habits my kids have picked up recently...

bill von novak

Palanakonu said:

BB thank you for a thorough and somewhat confusing set of replies. I understand *most* of what you are saying, I'll figure out the rest as I re-read it, over and over and....

From what I am gathering now, and looking at the budget I have for this, I believe I might be better off starting with the smallest system I can that will just run the bare minimum (fridge, lights, pump), and then saving about $8k for the final system. Then either selling the smaller system or keeping it on hand in case I need to take the main one down completely for maintenance or some other unforeseen circumstance.
As for your last comment - we are one of those fortunate families that do not have debt (credit card or otherwise). People often ask how we can live in Hawai'i with such a limited income (by Hawaiian standards)... it's because we own everything we have and owe no one. It's nice to wake up and feel that kind of freedom.

Any input on the idea I had above? Just a small 24v system to power a fridge and such, with the genset to run the washer of course, then getting a whole new system 6 months to a year later?
I know it might sound outrageous to people used to having a television and 3 computers on all day and night, but around here that kind of stuff is just.... strange - except for the bad habits my kids have picked up recently...

Some suggestions:

If you want to start small, you can still start with components you can grow into later.  For example, start with a Radian (or equivalent size) inverter and a 48V system with the minimum recommended Radian bank size (which I think is 200ah for short-duration use.)  That will also allow generator support.  You can do that with 8 golf cart batteries ($1000 or so.)

Add solar gradually.  You can start with a very cheap PWM controller then move to a larger MPPT as you can afford it.  Choose the most common panels you can get locally; it's easier to grow a system with the same panels than with different ones, and you will probably end up with fairly high voltage strings.  (Which is hard to do with dissimilar panels.)

BB.

The "minimum" system that would probably work with a standard Energy Star Refrigerator:

• 1,500 Watt AC inverter
• https://www.solar-electric.com/samlex-sa-1500-112-sine-wave-inverter.html $530
  
• ~600 AH @ 12 volt battery bank (2x6 volt 200 AH * 3 parallel strings)
• $100 * 6 = $600 (Costco/Walmart continental US)
  
• 600 AH * 14.5 volts charging * 1/0.77 panel+controller derate * 0.10 rate of charge =1,130 Watt array "nominal"
• 1,130 Watts of solar panel for ~$1.00 per Watt or ~$1,130+shipping cost (need MPPT charge controller for Vmp~30 volts or higher)
  
• 60 amp minimum MPPT charge controller:
  
• https://www.solar-electric.com/motr60ampmps.html $600+meter (if you want it)
• https://www.solar-electric.com/mnclassic.html $550
• https://www.solar-electric.com/outback-power-flexmax-fm60-150-mppt-charge-controller.html $455
• https://www.solar-electric.com/xaxwmp60amps.html $600
• plus a remote temperature sensor. Less than $50
  
• Solar panel mounting, wiring, breakers, electrical boxes, surge suppressors if you get lightning.
  

Such a system would supply:

• 600 AH * 12 volts * 0.85 AC inverter eff * 1/2 days storage * 0.50 maximum discharge = 1,800 Watt*Hours per day for 2 days of "no sun"
• 1,130 Watt array * 0.52 AC system eff * 5.08 hours of sun per day (ave December) = 2,985 WH per day minimum average December day

Your refrigerator + AC inverter should use less than ~1,500 Watt*Hours on an average day. If you convert a chest freezer to refrigerator, it will use about 250 WH per day typical (your warm climate, will probably use more).

The above would be about the minimum I would suggest for a full time off grid home with a refrigerator. You can probably get away with a smaller array--But I would not recommend it. Solar panels are "cheap these days"--Gives you more energy to play with during the middle of the day and still keep the battery bank relatively happy (TV, tools, washer during sunny days, etc.).

Above links are to our host NAWS (Flagstaff Arizona). Links are to products that approximately meet your needs and are not too expensive (but good quality). You still need to review their specifications and your needs--If you have questions, please ask here. There are other products that can work well too (from NAWS or elsewhere). This is not a recommended shopping list by me. I am not off grid and I am not in the solar business.

-Bill

westbranch

I like what Bill says immediately above....just that if you can swing it I would add 2 more batteries and ~ 400 more watts of PV , change to 2 parallel strings of battery in 24V config.....  and you have 25% more capacity.. you will have to change a few of the small parts to match up with the Voltage change.
hth

Lumisol

You are powering a router and not a computer or monitor?

Dave Angelini

I like what westbranch said but with 1 string on 400 AH L16!

Palanakonu

BB. said:

The "minimum" system that would probably work with a standard Energy Star Refrigerator:

This is exactly what I needed!
Now I have a working idea of parts/products and price.
Thank you BB, you have been a great help with this.

Palanakonu

Lumisol said:

You are powering a router and not a computer or monitor?

This is correct.
The router connects to 4G and is mainly for our camera system.
We do have a "SmartTV" and stream something from time to time.
We have a single laptop that uses 4G for internet, the same with my wife's tablet. These devices are usually left in the Jeep and are charged there as well. It's VERY rural where we are.

mike95490

I gave you estimated specs for the router power, 480wh.  How many cameras and how much power for them - it could be real easy for many cams to, over 24hrs, consume 1Kwh    Better find out BEFORE you buy gear.

Palanakonu

mike95490 the cameras are wireless battery operated cameras.
Yes, they do need to be recharged, but that depends on how much they record. I get on average about 3 months on a charge from my most used camera, and the least used is about 8 months now on a single charge.
I considered them negligible in this and figured I'd charge them on the Jeep inverter if it was necessary.

mcgivor

Off topic question, are you going to build a traditional thatched Hale? Was thinking about that last night during a 8 inch downpour onto my metal roof, would be significantly less noise with a thatched roof.

Dave Angelini

Palanakonu, nice name!  I try to avoid my clients make bad decisions ! They love it! Not often till later. The old saying it takes money to make money. A 12 v system is just a waste if you think you really love the place and are going to really make this happen.

Bill gave good advice on how to do this to your guidelines as did most everyone.

If it were me and I could save $1700 a month I would move onto your land and buy ice for a month.

The next month I would buy a 24V bank of batteries, an inverter/ charger and a 36V nominal solar panel. Buy some gasoline for a 2 hour run each day. Use the new refrigerator.

The next month build a proper solar array. With the 24V bank an mppt can easily have room to grow up to 2KW of solar.

Good Luck!    Many of us started this lifestyle a long time ago.   No need to make costly mistakes if you are on a budget.

mcgivor

First I went the ice route, soggy everything, next the chest freezer, inconvenient, like living out of a back pack and wasn't as efficient as the claims, best thing I ever did was get the inverter refrigerator with a freezer, I'm remote and need to store a weeks worth of food. Wish I had known what I didn't when I started, but we all learn one way or another, for me it was from mistakes, so be it. Having the benifit of information is invaluable, but sometimes the information leads to confusion, basically the way I see off grid living is the refrigerator is the most important load, others are secondary and many can be used as opportunity loads, when charging is almost complete, it's amazing how little energy you can get by with other than the refrigerator.

Estragon

For the first few years at my cabin we got by on a couple of golf cart batteries and a cheap inverter. We ran a generator to run tools and the fridge for a few hours daily, and used freezer packs and well insulated coolers. Water pumped up to a cistern and gravity fed to cabin.

I'm glad we did it that way. When we eventually finished building the structure to mount the panels and bought the gear I had done a ton of reading and felt pretty comfortable about building a system that would work for us, and understood the trade-offs involved.

Dave Angelini

If you can find an Inverter fridge like the LG, it will save needing an Inverter that can surge to start motors. Just make sure that your pumping can slow start.

It is a little different from a cabin as this will be a home for 4 people full time. They are still clearing brush but I think until there is a structure to shelter from blowing rain all of this is on hold.

westbranch

FYI our GE 18 cubic , just pulled ~1000 W , biggest instantaneous Amperage dip I have managed to record in 3  years since we put it in...  plain jane model , no bells ...  top freezer, has some sort of soft start that GE will not reveal despite repeated requests.. hth

Palanakonu

mcgivor said:

Off topic question, are you going to build a traditional thatched Hale? Was thinking about that last night during a 8 inch downpour onto my metal roof, would be significantly less noise with a thatched roof.

Unfortunately, no. I would love to live in that style, but the thatched roof invites insect infestation on a biblical scale! For us, "take me back to my little grass shack" means post-n-pier, single wall, and a metal roof (we will have catchment). Though I'll be providing sound deadening between the metal and the sheathing.

Palanakonu

Dave Angelini that gives an interesting option.
I have been digesting what BB said and like it, especially with the addition that westbranch mentioned in the following post.
We would most likely outgrow a 12v system very fast. Looking at the cost of 24v components vs 48v and it does make this very doable.
If I could mix the genset into there to charge the batteries that would be awesome. I assume it would be a certain type of inverter that I wire the generator into for this? Or does the CC handle it? Or given my budget would a standalone 24v charger be better? Since I've never considered it until  now I've never looked into it. I guess I will now.
That would allow me more wiggle room with my funds, possibly skipping the panels for the first month entirely and just charging with the generator. Any thoughts on this?

Right now all of this is purely academic. I have no idea how much money I really will have to devote to this. I could easily have more than what I estimated.... or less. So I'm just trying to cover all bases.