Looking for opinions on new off grid conext, outback system 2019

mikeh79

Hello everyone,

I am looking for info on the conext and outback systems to see if some issues have be resolved, most of the threads I've seen are older and haven't seen any newer one close to my application. 

We have been living off grid for four years, but not very efficiently.  We had our home burn and moved to our other property which the electric company wants 25k to bring a line to me. We like the idea of staying off grid since we would be at the end of the line and only a few houses on it, figured if the grid goes down we would be last to be fixed and cost of course. 

We have been using a 7kw gen with two automotive chargers charging 8 crown 205 batteries, and a harbor freight 5000 watt inverter.  It does work for us but finally things are turning around for us so I am looking at putting in a 15kw gen, 3.5 -4 7kw array figuring to double that in near future, using (2) conext 6848 inverters, (1) 80 600 charge controller, with expectation of adding 1,  all the supporting ags, scp,and battery monitors, along with 16 crown l16 430ah in two strings. 

I like this system because it seems to be easily expandable. I don't have a good idea of what loads we may need to prepare for, so far we usually run the gen half loaded roughly.  My goal is to get rid of prioritizing chores, weather do a couple loads of Landry or run dish washer sort of thing, so Our loads would vary considerably some days heavy but some almost idle. I also want two of everything for redundancy.  Our major loads are on propane (clothes dryer, cook stove, water heater). 

I have studied the conext system very well and it seems like it would suit great, as it can give me graphs and info on what I'm using verse what I'm lacking and need to expand.  But I haven't researched outback very much and what I've seen is mixed components from different manufacturers, I would like one system one manufacturer as they should be made to work well together. 

Any help in the issue would be greatly appreciated  THANKS.

mike95490

Do you have air conditioning or commercial flash freezers ?   What else do you need a 15kw generator for ? 

You HAVE to work up a spreadsheet with your house loads on it, 
bedroom LED Light  20W  4 hours
Kitchen LED lights  40W 5 hours
Dining room LED lights 30W 4 hours
TV & music center 90W 6 hr
fridge   200w,     1.2 kwh daily
Microwave 1400w .25 hr
Toaster  1400w .1 hr
Garbage disposal 1400 .1 hr
sewage pump 1/2 hp 1200w .2 hr
well pump  1/2 hp  1200w  .4 hr
   Figure how many will be on at once, microwave, lights, pump, disposal,  that's what the inverter has to power or you go dark and have to reset stuff in the dark.   unless you have air conditioning you likely don;t need more than 5kw generator, but I'm sure someone will sell you one !

mikeh79

Hi Mike 
I really don't know how to figure loads for my application.  My wife also has a disability so days she is good others she is not and I work a lot of 12hr shifts.  Some days we may wash and dry 6 loads of clothes along with dish washer, vacuum that sort of thing with our kids helping.  We have had to manage what we do so far as I have tripped overloads on the 7500 generac.   As of now we don't have a/c but plan on putting in this year as well and need to add deep freeze.  I don't like running anything at max capacity is why I like the idea of putting 2 conext 6848 and the gen size I was told I need to double my inverter size so the gen can power loads to house and inverter will pull almost it's size in charging batteries . Also the generators I'm looking at 6kw at full load uses .47 gal hr  where the 15kw uses .61 at half load which is almost same usage why not have reserve in case needed.

BB.

I am not the expert on these choices... But I would suggest that you look at the current Schneider XW (XW+?) product line.

From what Dave A. (poster and installer) has said, those are the units you need if you want reliability and long term life.

Using inverter based mini-splits for A/C (or heat pump versions if you need heating too) are very good and don't have high starting surge current (basically, soft start with max surge and max power consumption about the same).

As Mike'95 has said... You really need to know your loads. And make choices (new lower power/surge appliances, new Grundfos well pump, possibly making deep well to cistern, and use a second RV like pump to pressurize home water from cistern, etc).

$25,000 to bring utility power to your home... Probably your best investment. Both in terms of actual costs (need to check/estimate what your utility bill would be with service and per kWH charges would be) and if/when you (or your heirs) go to sell the property (it seems the costs to run utilities to a remote home are only going up over time). Add/continue your use of a genset for backup power.

As you get older, the efforts (and money) needed to keep your off grid home going may exceed your reach.

Are you planning on doing this as a DIY? Or hiring (hopefully) a local and competent installer?

Part of your energy planning process could include a whole house monitoring system (some have multiple sensors so you can monitor major circuits (well pump, A/C, Heating).

https://www.theenergydetective.com/

A 2x 6 kW or 12 kW off grid system is very large and expensive... It may make sense for you (home business, family needs, etc.)... But conservation is usually the first and best place to spend your time first when going off grid. It is almost always cheaper to conserve energy than to generate it.

Please note, we realize that energy usage is a highly personal set of complex decisions. I am suggesting you make those decisions rationally. For off grid power, it is not unusual for it to cost $1-$2+per kWH of "solar" and genset power. Compared to $0.10 to $0.40 per kWH (in the US, depending on where you live).

If you were running 3.3 kWH per day or ~100 kWH per month, those are "medium" sized off grid power systems that don't need a 2nd mortgage to finance and can be done DIY pretty successfully. And are maintainable by the owner.

If you are in the (far) North/Central US, winter sun can be pretty weak and rare. Solar, obviously, does not work well during those times.

-Bill

mike95490

Wow.   6 loads of wash & dishwasher  & future plans for A/C  .   you are going to spend $25K on batteries in 5 years .   Seriously, you should look at the Grid Connection.   

My suggestion:

Grid connection   $25K
15 - 20 KW whole house backup genset  propane or diesel with whole house transfer switch.  $15K

Now you have all the cheap power and it's un-interrupted .  Run a couple days on the genset while the power lines are repaired. Cut the genset off at night, and use flashlights. 
 Wire a "blackout" panel that runs the fridg and TV outlets, and some ceiling lights, and run a 2Kw inverter genset for that at night, just fire the big genset when you need the dishwasher and laundry.

That system would require a HUGE battery bank and just 1 mistake and you kill the battery and have to buy a new battery.   Battery would be a forklift size battery, your current battery is likely maxed out without adding new loads.

You can always add a large PV system later, and sell back to the grid to offset your bill.

Estragon

At $25k for grid connection, I would have been inclined to go grid.  On-grid, the grid is a sort of infinite battery, which doesn't care if I run the washing and the well pump and the dishwasher at the same time.   Supplying it is their problem. 

Off-grid, that becomes my problem, and it's expensive to do on a small scale.