I depends on your electrical rates and why you want to buy a SolArk..For the kind of money that you would spend on a SolArk, to just use it for backup is more wasteful than the 2 kWh per day it consumes. You can spend a lot less on a backup inverter.
The SolArk is a grid interactive inverter that can cave you many more kWhs per day. Worrying about 2,4 kWh per day is looking at the wrong issue. Perfect should not be the enemy of good.
The main reason I am looking hard at the 15Kw Solark is as follows:
1.0 Only hybrid inverter I found that will allow me to AC couple 100% of my enphase inverter array
1.1 Install of this kind of hybrid inverter with AC couple feature allows me to make good use of the Enphase AC solar in back yard when grid is down. Without this hybrid inverter that investment is useless in a grid down situation.
2.0 Has slots so I can add additional solar as DC solar input if desired in future. (Future proofing)
3.0 Is pretty highly rated, and doesn't require special software to control
4.0 Is large enough so no "stacking" is needed (added complexity and cost)
5.0 May allow me to avoid any need for a second "critical needs panel"... current plan is to hook up this unit directly to my main power feed input. (less complexity and less cost)
If you know of a backup inverter that will charge batteries and accept 100% of my installed solar 10-11Kw of AC coupled solar input I would be very glad to hear the options.
I don't fully understand how the "grid interactive" features will help me save money. As of now I don't have any time of day electric rates, but If that changes that feature would be nice.
Can you please explain how the Solark will save me money during normal operation with solar up, batteries charging/fully charged, grid up? I am looking at it primarily as an insurance policy for an extended grid down period.
Am I missing the boat here? Again I am a rookie.
I agree with your general comment that worrying about the standby power usage is a little "anal" but...if I can overcome that issue with a simple switch moving the AC coupled solar, why not.
I have a 2Kw inverter in my RV, and the manufacturer says they recommend turning it off when not needed, or on shore power. Not sure why I couldn't use the same approach with this larger more complex box.
I also still wonder why Solark couldn't use firmware to direct the standby power needs to batteries or solar as available. That seems like a good simple solution... and then every morning the battery usage is refilled by the solar.
EDIT/UPDATE FROM July 8th below
=================================================
I contacted Sol-ark about the 2kw daily power usage in standby, and they confirmed that you can modify the settings so that at night time you select how much power to draw from the battery. You can also set a battery depletion amount to protect your batteries from fully discharging overnight. So if you have excess solar during the day, and are using net metering, you would assume that 100% of the standby power is either solar, or battery non from grid.
I sent a follow up question to confirm that assumption, and they admitted that is the "intent" of the design of the device, but currently there is a "bug" that means that most of the standby power used during the day actually comes form the grid. And they are working to address that issue.
I was happy that they reported a "bug" openly and didn't just claim that by correct use of the inverter you can eliminate any standby power from grid (that you pay for).
I did not send a third follow up email asking for any further details, I just was happy that they replied in a timely manner and indicated they are aware of an issue with the source of the standby power.
So.. I guess we can wait and see what happens and when. I guess my current view is that if I can setup the inverter to only use 1kw from my battery overnight, and my batteries are fully recharged each morning, the concern about standby power I had goes away.
Thanks to all who replied, as I said I am still a rookie and learning this stuff.