Off Grid Inverter Recommendation?

[Off Grid Virginia]

Looking for simple reliable whole house off grid inverter recommendation?

I won't need any grid tie.

Looks like some have solar charge controller built-in meaning one less thing to connect externally, maybe this is better/simpler? Just connect PV wires, 48VDC battery in and 120/240VAC out?

I'm also thinking 1 unit would be simpler than 2 units in parallel, but for a whole house 2000 sq ft. with traditional electric appliances, HVAC etc. thinking I may need a 15KW inverter? Not sure.

What do you recommend? and Thank you.

 

[Brucey]

From NAZ:

One to four Schneider xw pros (6.8kW rating with surge to 12kW for 60 seconds). $900 each

Insight Home to configure and monitor. $200.

One or more Victron 250/100 sccs from Current Connected ($574 each member pricing).

If you need grid or gen transfer over 60A (three+ inverters) then a Schneider BCS as external transfer switch ($580).

 

[BentleyJ]

@Brucey Why would you not recommend the PDP and Conext charge controllers as well to take advantage of the Xanbus network.

 

[Brucey]

@Brucey Why would you not recommend the PDP and Conext charge controlles as well to take advantage of the Xanbus network.

Because of the cost.
$900 for pdp then $520 for each additional inverter kit.
I would have said maybe get four mini pdps for $300 each but now they are back up to $420.

I mean definitely if you had the budget could just get a bunch of 600/100s, insight facility with two xanbus channels, four xw pros on one, eight 600/100s on the other, midnite 2000A combiner box with mnedc250 breakers.

 

[Madcodger]

100% off grid here, in Maine. I have one building with EG4 6000XPs. They work great, but make a lot of fan noise. Fine for that building as it has a dedicated, nearly soundproof mechanical room. It's an AIO, so charge controller included. No complaints at all other than the noise.

For two other, small buildings where we might hear the inverters (or more likely, a charge controller that uses a fan, such as the EG4 equipment) we went with Victron equipment. Their smaller charge controllers (250V or less) are passively cooled, so no noise at all. Their larger ones (up to 450 V) are quieter than many others. Victron inverters tend to run quietly UNLESS you are running them at 50% or higher capacity, and then you can hear the fans. Given that you need to size an inverter to handle peak loads, that just shouldn't happen very often.

Hope that helps.

 

[SnickeringBear]

You have suggestions for inverters, but so far nobody has posted about power consumption. Get 2 inverters rated 10 kw each, 60 kWh of battery storage, and 12 or more kw of solar panels. This is a starter system for an ordinary home. If it is not quite enough, add more capacity later.

 

[Off Grid Virginia]

Thanks for the replies.
SnickeringBear: Really, that much? I was guessing maybe 15KW inverter, 4 to 6 5KW batteries and 8KW in panels?

I have seen people say the Schneider 6.8KW is the best deal right now at $900. Sounds like it does not have solar charge controller built-in?

Just thought it might be simpler to get an all in one unit? And do it with 1 inverter if possible?

I don't see much in a single inverter in that size, though, but I'm sure there's plenty of people powering their whole house off grid, just not sure what they're using?

Current connected first told me to get 2 x EG4 6000's and I said what if I need more than 12KW then he said get the EG4 12000XP and if I need more get a second one. It seems to me like the EG4 and a powerwall 280AH battery or 2 might be the simplest setup / least components to buy? But I've heard mixed reviews on the EG4 reliability? And I guess 12000 is the biggest one they offer?

Not sure what else is available in that size class?

I also see what looks like a good deal on a used Sungold Power 48V split phase pure sine wave inverter charge 15KW LFPV but I think this lacks solar charge controller?

I'm still thinking 1 single inverter, and possibly an all-in-one, might be the easiest setup for a first time person or no? If so, what are my options in the size I need?

 

[SnickeringBear]

Do some due diligence. Inverter capacity is determined by the max kWh used in a single hour for the highest usage hour of the year. If you use 12 kWh or less in the highest hour, you can do this with a single 12 kw inverter. If you use more than 12 kWh in the highest usage hour, you need 2 inverters that total more than your actual usage. There is still some finagle room even when calculating with this method as you can have heavy loads for say 10 minutes that exceed 12 kWh followed by lower usage the rest of the hour.

SRNE HEBP 12 kw inverters have a pair of 9000 watt MPPT's. Two inverters get you 36000 watts of capacity to feed an inverter and/or charge batteries. This means you have flexibility to grow the system in the future as needed.

What about battery size? It is determined by the amount of power used by the home on a daily basis. Say you use 45 kWh, you need at least 45 kWh of battery storage.

You did say a house load of typical appliances. Figure out what your "typical" appliances are and how much power each consumes daily.

 

[Off Grid Virginia]

I thought inverter size was determined by max loads pulled at one time? Example: The oven is on, the dryers running, the hot water heater, the well pump, then AC kicks on. I thought I'd need an inverter sized to handle however many watts that is?

Let me know if that's right or not, but either way I am just guessing at what size I need because it's a new build with no electric company or electric bill to look at.

 

[42OhmsPA]

I'll drop this here to give you some ideas.

You really need to figure out your loads, constant, surge, and peak before buying anything.
A good clamp meter capable of reading inrush current should be your first investment if you don't already have one.

 

[42OhmsPA]

I thought inverter size was determined by max loads pulled at one time? Example: The oven is on, the dryers running, the hot water heater, the well pump, then AC kicks on. I thought I'd need an inverter sized to handle however many watts that is?

You've pretty much got it but you need to understand inrush current on the inductive laods. The AC and well pump will be significant. For example, my well pump pulls ~40A a leg for a split second. I never clamped the old central air unit, went the mini split route and haven't looked back.

Let me know if that's right or not, but either way I am just guessing at what size I need because it's a new build with no electric company or electric bill to look at.

That is going to make it difficult. Do you have a bill from the prior residence to reference?

Focus the build on efficiency.
Insulation and air tightness are huge.
Grundfos well pumps are awesome.
Inverter based compressors that ramp up slow for hvac.

 

[SnickeringBear]

I thought inverter size was determined by max loads pulled at one time?

That is the "finagle room" I mentioned. You don't calculate it for all to be on at the same time. Instead, calculate what will happen if 4 of the 5 heaviest loads are on at the same time.

Using an example, say you have an electric stove pulling 30 amps, well pump pulling 10 amps, heat pump water heater pulling 4 amps, and heat pump air pulling 20 amps all at the same time. That is 64 amps. A single 12 kw inverter can produce 50 amps. Ergo you need 2 inverters.

Here is a list of loads I put together for my tiny home. Home work shop and swimming pool are just added so others have an idea what to expect. I don't have them.

1. Heat pump fuses at 30 amps 240V, normally uses 20 amps, 15 kWh/day
2. Electric cook stove fused at 50 amps 240V, normally uses about 25 to 30 amps, max 40 amps, 7 kWh/day
3. Heat pump water heater, fused at 30 amps 240V, normally uses 2 amps (20 for heating elements), 3 kWh/day plus 2 kWh per additional person
4. Stackable washing machine and heat pump dryer, fuses at 30 amps 240V, uses 10 amps, 3 kWh/day
5. Submersible pump in the well, fuses at 20 amps 240V, normally uses 15 amps, 2 kWh/day
6. Refrigerator fuses at 20 amps 120V, normally uses about 5 amps when running, 2 kWh/day
7. Upright freezer will be similar to the refrigerator with 5 amps when running, 2 kWh/day
8. Dishwasher fuses at 20 amps, normally uses 10 amps, 1 kWh/day (using eco mode)
9. Microwave fuses at 20 amps, normally uses 15 amps, .5 kWh/day
10. Air fryer, fuses at 20 amps, normally uses about 16 amps, .5 kWh/day
11. All other miscellaneous items will draw about 20 amps max, tv, computer, hairdryer, etc., 1 kWh/day
12. Swimming pool, circulation pump, heat pump heater, all together can pull 40 amps 240V and can run 18 kWh/day
13. EV charger normally fuses for 40 amps at 240V with typical pull of 20 kWh/day
14. Home work shop with power tools normally fuses at 50 amps 240V and can use 20 kWh/day

 

[ZePrez]

I thought inverter size was determined by max loads pulled at one time? Example: The oven is on, the dryers running, the hot water heater, the well pump, then AC kicks on. I thought I'd need an inverter sized to handle however many watts that is?

Let me know if that's right or not, but either way I am just guessing at what size I need because it's a new build with no electric company or electric bill to look at.

And you are right.. but please understand that, some loads draw a lot more current, thus power when they are starting, those tend to be the things with an inductor, anything with a motor in it... if some of these starts at the same time .. you could draw for a short moment more than the inverter is capable of.
Let's take the exemple of a generic 6 KW inverter.. with a surge capacity of 7 Kw.. someone doing the laundry, a task that could create a condition where the water pump, the washing machine, pump and/or motor and some house AC compressor starts at the same time.. In which case the 7 KW surge-rated inverter is likely to balk and enter protection...

OTOH you have another 6 KW inverter but with a surge capacity of 12 KW for 30 seconds.. It is likely to just run without any issues...

... Providing the batteries are capable of supplying the current the inverter will need for that 12 Kw surge...
Thus...
You need to have an idea of the power and surge ratings of the appliances you will use...


This Post too by @42OhmsPA

 

[Madcodger]

We use electricity for everything except heating the garage and entry foyer of a 36x44 foot building with two stories (apartment on second floor). I have three 6000XPs but have never been in a situation where the third one was actually needed, and that includes preparing Christmas dinner with an induction range and convection oven, at least one crock pot that I recall, in a heat pump-heated living space, while doing laundry, with the well pump kicking on periodically. We do use a heat pump dryer and Grundfos SQ well pump amd the building is super insulated. I've actually walked around the house turning things on to try to max out, and I couldn't do it. I think I'd need to fire up the welder on Christmas day to do it. Anyway, one guy's experience. How people max out multiple large inverters amazes me.

 

[Norwasian]

SnickeringBear: Really, that much? I was guessing maybe 15KW inverter, 4 to 6 5KW batteries and 8KW in panels?

This isn't a balanced system. If you need 15kw of inverter and 30kw of batteries, why would you presume that 8kw of panels will keep up with the demand? Besides, cloudy days happen. You want a system where the panels' capacity is greater than the inverter output--unless you have a setup where the inverter will not be in constant use, e.g. you can charge the batteries for several days, then draw them down with the inverter for weekend use.

I'm sure others will say I could have set things up better, but after doing considerable R&D for my first system, I installed 7kw of panels for a 3kw inverter, based on a 15kw battery. The battery is enough to last two or three dark days. It typically draws down only 15-20% at night, and is fully recharged by 11 a.m. On a cloudy day, it might be recharged by noon or 1 p.m.

With a 3kw (toroidal, LF) inverter, it runs the refrigerator, washing machine, rice cooker, lights, fans, digital devices/phones, an iron, video projector and sound system, etc. (of course, not all at once), without issue. But it's not powering A/C: for that a larger inverter would be needed.

I think the inverter should generally be the "bottleneck" as it were, i.e. the point of least capacity/demand. Give your batteries and production more ability than the inverter, and the inverter won't be able to easily run them out of power.

 

[Brucey]

[.

I thought inverter size was determined by max loads pulled at one time? Example: The oven is on, the dryers running, the hot water heater, the well pump, then AC kicks on. I thought I'd need an inverter sized to handle however many watts that is?

Let me know if that's right or not, but either way I am just guessing at what size I need because it's a new build with no electric company or electric bill to look at.

With something like an xw pro, say you are running a pair at 12kW and your well pump kicks on. Might need to surge to 18kW+ for a few seconds for the pump startup. Thats not a problem for an xw pro system.

However for most HF inverters, you arent going to get a surge to 18kW, so you'll need two 12kW inverters to cover that max 18kW load.

So there's some flexibility there, if your baseloads are usually below an xw pros rating but there's shorter term spikes above 6.8kW, you may be able to get fewer units than you would otherwise need if going with most hf designs.

Anyway at $900 each no reason not to have three or four.

 

[Quattrohead]

New build, permits and inspections or none required?
Then, are you anticipating using propane for anything.

 

[Brucey]

New build, permits and inspections or none required?
Then, are you anticipating using propane for anything.

Xw pro doesn't have latest ul1741sb if he's contemplating grid-tie in some jurisdictions but sounds like he's off grid.

 

[SplitUniverse]

Look into HV batteries and inverter, you will save a BUNCH just in wiring.
120KW DDP shipped HV battery is about 14K from alibaba. Solis S6 inverters (11KW each) can be had for about 2K a piece (sungold rebrands).

Otherwise the XW Pro and some Suyego MPPT chargers, they even have 500V input units that have CAN bus coms.

I have a hard time seeing a situation where 2 XW Pro would not handle the house loads, 12KW continuous is a LOT of power.

 

[Hedges]

Other inverters to consider include SMA Sunny Island and the relatively new Midnight Rosie.

"HVAC" - what type of heat? Cooling? Do you need A/C only when the sun is beating down, or all night?

"4 to 6 5KW" - how about fewer, higher capacity in the 12 ... 15kW range?
Recently saw a link to a 30kW battery but its discharge current might limit the wattage available.

 

[ZePrez]

Hi

On this , nothing angainst the Schenider or other inverter with big transofrmer allowing those to deliver some substantial surge.. One needs to understand this is ONE method to deliver surge.. Not the only method. it is perfectly poissible to design (at a cost I preseume) a HF inverter cpable of delivering substantial surges. SRNE for one boast such capabilities. Have these been verified? IDK and would like someone to point me toward such reviews or measurements... from the specs sheet:



If it is 10 sec it is substantial... For perspective the compressor of the average Residential 5-ton AC is about 3 HP... for a high-flow well pump (for multiple dwellings) you are around 5 to 6 HP... within the stated (not verified by me) capabilities of the <$2,000 high performance and so far, flawless (for me anyway) ASP-10 KW... and there is the Luxpower 19 Kpv who was tested/reviewed by @Will Prowse ...
I would not go toward the Schneider if you were to ask me.. too locked-down and closed-in...

My take...
Peace

 

[Norwasian]

Hi

On this , nothing angainst the Schenider or other inverter with big transofrmer allowing those to deliver some substantial surge.. One needs to understand this is ONE method to deliver surge.. Not the only method. it is perfectly poissible to design (at a cost I preseume) a HF inverter cpable of delivering substantial surges. SRNE for one boast such capabilities. Have these been verified? IDK and would like someone to point me toward such reviews or measurements... from the specs sheet:

View attachment 320873

If it is 10 sec it is substantial... For perspective the compressor of the average Residential 5-ton AC is about 3 HP... for a high-flow well pump (for multiple dwellings) you are around 5 to 6 HP... within the stated (not verified by me) capabilities of the <$2,000 high performance and so far, flawless (for me anyway) ASP-10 KW... and there is the Luxpower 19 Kpv who was tested/reviewed by @Will Prowse ...
I would not go toward the Schneider if you were to ask me.. too locked-down and closed-in...

My take...
Peace

Ooh, that's a bit of sleight of hand there in those figures. They're comparing apples and oranges with their "rated output power" versus their "Max. output power." They're literally using different units of measure for these!

If you're running a motor that starts off at a 0.4 PF, then you'll only get 14,000 watts of surge...not 20,000. In theory, that 20,000 watts of surge will never be available for an inductive circuit (motors), but will only be viable for a resistive circuit (heaters, digital devices, etc.). But the fact is, resistive circuits don't surge...it's motors that surge!

In other words, 20,000VA is not 20,000 watts, and it does not even have twice the rated amperage available for surge to help start a motor.

Stick with an LF inverter and you should get the full rated surge capacity, usually three times the continuous rating.

 

[42OhmsPA]

There are different versions of the manual / spec sheet.

 

[Quattrohead]

120KW DDP shipped HV battery is about 14K from alibaba

I would not spend any more than $20 on there, certainly would never buy something that could burn your house down.

 

[42OhmsPA]

I would not spend any more than $20 on there, certainly would never buy something that could burn your house down.

From alibaba? You're missing out.