Whole home off grid 240v setup

[littleharbor]

He want's to be "self sufficient"

[J.P.M.]

Define expensive? Was expecting about 5k in batteries, 7.5k in inverters, 2k in wire/boxes/cutoffs etc. I have a midnite solar for the Mppt on the 115v, I have the solar panels, just need a solid 6-8kw inverter, which magnasine and others run in the 2k range. This is my retirement home so we will have 25 yrs to recoup what I think will be a 25k investment.

We readily have have access to the power grid.

How often does your power go out ?
Do you have mission critical applications ?

Off grid costs a lot of money. A lot more than most people think. It's also a lot a hassle. Most folks are clueless about that as well.

If you have access to reasonably reliable grid power, be like the smart folks - buy a generator and skip the off grid.

[ButchDeal]

So here are my thoughts:

1. I will hook up to the grid initially with 120/240
2. My first replacement will be a grid tie inverter charger for the 120v about 6kw max. This should be easy area to start and I can start with a modest battery bank. Leave the 240v On grid at first. This will also let me see how the house performs and what needs I will have on the 240 side.
3. Do gridtie inverter without batteries on the 240v side eliminating 80% of my power demands on this side.

if done correctly this should supply 90-95% of my energy demands and yet allow for a reasonable resilience if the grid goes out or zombie apocalypse, lol!

this should limit my costs, the batteries in the 115v side should hardly be drained at all.

This is only a good idea if you like Rube Goldberg machines.
There are these systems called Bymodal inverters which can do what you are talking about with a single system.
Much more reliabley.
Take a look at OutBack Radian, or SolarEdge StorEdge systems.
You would have an on grid system with some back up capabilities for an emergency panel of the critical things you want to keep running in your home.

[Sunin]

So here are my thoughts:

1. I will hook up to the grid initially with 120/240
2. My first replacement will be a grid tie inverter charger for the 120v about 6kw max. This should be easy area to start and I can start with a modest battery bank. Leave the 240v On grid at first. This will also let me see how the house performs and what needs I will have on the 240 side.
3. Do gridtie inverter without batteries on the 240v side eliminating 80% of my power demands on this side.

if done correctly this should supply 90-95% of my energy demands and yet allow for a reasonable resilience if the grid goes out or zombie apocalypse, lol!

this should limit my costs, the batteries in the 115v side should hardly be drained at all.

[Sunin]

If you have grid power available at a fraction of the cost of an off grid system why would you consider spending so much, only to continually replace batteries every3-6 years..
The propane tank is still a good idea. A propane Genset will give you all the power you need for periodic grid outages if you feel the need.

Mainly to be self sufficient

[littleharbor]

If you have grid power available at a fraction of the cost of an off grid system why would you consider spending so much, only to continually replace batteries every3-6 years..
The propane tank is still a good idea. A propane Genset will give you all the power you need for periodic grid outages if you feel the need.

[Sunin]

And Gas powered stoves and dryers.

The more I think of this the more I contemplate if I should get a large propane tank for these two appliances. That would only leave a 1 1/2 - 2 ton trance xv20i running on 240.

[Sunin]

Outback Radian. Good to 8000 watts each, 12000 watts for 5 seconds. You'll probably need 2 to be safe.

Note that the inverter will NOT handle 600V from the array, nor does it have to. You will need charge controllers (and at 600V your two choices are really Morningstar and Xantrex/Schneider) The charge controller drops the 600V to 48v and the inverter uses the 48V. At 18kW that's probably 6-7 controllers at $2K a pop.

Your battery bank will, of course, have to be huge. At least 140 kilowatt-hours if you go flooded lead-acid, or 3000 amp hours. Surrette-Rolls sells 3400 amp hour 2V batteries for about $1K so that's $24,000 of batteries.

Thank you for the in depth analysis. My power usage right now is 30kw a day and 80%-90% of that is during daylight and this is on an inefficient home. Some inverter/chargers I was looking at is the sunny boy 11000tl, VICTRON ENERGY QUATTRO 48/15000/210-100/100, and a sneider product. I'm also considering not worrying too much about the 240v setup as far as battery backup, maybe add a small generator, maybe. The house has an r value above 50 and is designed to incorporate passive solar, it is entirely Concrete.

[Sunin]

And Gas powered stoves and dryers.

This location has no gas service. It is electric and water only.

[Sunin]

Is this all for hobby reasons or you simply don't have grid power over there? It's going to be expensive.

Define expensive? Was expecting about 5k in batteries, 7.5k in inverters, 2k in wire/boxes/cutoffs etc. I have a midnite solar for the Mppt on the 115v, I have the solar panels, just need a solid 6-8kw inverter, which magnasine and others run in the 2k range. This is my retirement home so we will have 25 yrs to recoup what I think will be a 25k investment.

We readily have have access to the power grid.

[max2k]

I have 17.2kw of solar panels and I'm looking for an inverter/charger that outputs 240vac. It would be nice if it could be a 600v-1000v input from the array. I will be running 48v batteries, probably Trojan L16p(if I got the name right). This will run the A/C, dryer, and stove, so I would expect I need something in the 10kw range that can handle 15-20kw peaks for <20s. I've looked at fronius, sma, victron, and a couple of others. What I would like is options from quality manufacturers. Panels are solarworld mono black 285w x 60.

Last thing any quality ground mount units for 60 panels, I have acreage so space is not a concern.

more info: Yankton, SD does not permit net metering.

Is this all for hobby reasons or you simply don't have grid power over there? It's going to be expensive.

[jflorey2]

I have 17.2kw of solar panels and I'm looking for an inverter/charger that outputs 240vac. It would be nice if it could be a 600v-1000v input from the array. I will be running 48v batteries, probably Trojan L16p(if I got the name right). This will run the A/C, dryer, and stove, so I would expect I need something in the 10kw range that can handle 15-20kw peaks for <20s. I've looked at fronius, sma, victron, and a couple of others. What I would like is options from quality manufacturers. .

Outback Radian. Good to 8000 watts each, 12000 watts for 5 seconds. You'll probably need 2 to be safe.

Note that the inverter will NOT handle 600V from the array, nor does it have to. You will need charge controllers (and at 600V your two choices are really Morningstar and Xantrex/Schneider) The charge controller drops the 600V to 48v and the inverter uses the 48V. At 18kW that's probably 6-7 controllers at $2K a pop.

Your battery bank will, of course, have to be huge. At least 140 kilowatt-hours if you go flooded lead-acid, or 3000 amp hours. Surrette-Rolls sells 3400 amp hour 2V batteries for about $1K so that's $24,000 of batteries.

[littleharbor]

You should be looking at Outback inverters

And Gas powered stoves and dryers.

[ButchDeal]

You should be looking at Outback inverters

[karrak]

With such large loads and solar array you will need a very large and expensive flooded lead acid battery. It might be worth looking at a lithium ion based battery system. You will need a much smaller lithium ion battery to match those sort of loads and solar array.

Do a google search on LG Chem lithium, Fronius lithium, SMA lithium, Schneider lithium, Tesla Powerwall 2

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor
Latronics 4kW Inverter, homemade MPPT controller