Whole home UPS

[DIYrich]

The 16.7 KW figure is average over 15 minutes. Do not assume 16.7 KW is the inverter power you need to meet your peak demand.

At least it is as short as 15 min. When off-grid, two 15k's can handle 16.7 kw continuous for 15 minutes. Two can also surge to 48kW for 10 seconds, and 60kW for 0.1 seconds.

48kW is close to 3x average, so has a good probability of handling a motor turning on. Especially if Soft Start is added to the motors.

If you are going to plan for Load Shedding, then you need some type of automatic load shedding (such as using the Smart Load connection). You may not have time to manually load shed if the transfer happens automatically at the worst time.

 

[Solar_newb]

Then you should be fine on a solark 15k. Look at the spec sheet here - https://www.sol-ark.com/wp-content/uploads/2024/06/SK150-0001-002-15K-2P-N-EN-Datasheet.pdf

How much PV and batteries do you have or are looking to get?

Battery I can do as much as needed. PV, I am open to what everyone suggests is the best. Ideally going completely solar would be nice and only have the grid to handle any surge.


Let's say I go with either a Sol-Ark 15k or a Growatt SPH 10000TL besides PV and battery, what else will be needed? Is there anything that say the Growatt would need that the Sol-Ark doesn't need? Do I need to look into combiners or anything similar? I know I need the racking to mount the panels and of course electric wiring.

 

[DIYrich]

Let's say I go with either a Sol-Ark 15k or a Growatt SPH 10000TL besides PV and battery, what else will be needed? Is there anything that say the Growatt would need that the Sol-Ark doesn't need? Do I need to look into combiners or anything similar? I know I need the racking to mount the panels and of course electric wiring.

SA has built in isolator and breakers.
GW needs external breakers. If you parallel multiple GW, doing it via sub-panels is helpful. Individual units can be taken off-line for maintenance.

 

[Solar_newb]

SA has built in isolator and breakers.
GW needs external breakers. If you parallel multiple GW, doing it via sub-panels is helpful. Individual units can be taken off-line for maintenance.

I meant to also throw the EG4 18k in here. For my particular setup, is there one that makes the most sense? I am ok paralleling them.

 

[DIYrich]

I meant to also throw the EG4 18k in here. For my particular setup, is there one that makes the most sense? I am ok paralleling them.

My max 15 minute peak demand for the past month was 16.7kW.

If grid cutoff at the worst possible moment, you exceed the limit of one inverter (none are more than about 12kW-14kW from battery).

Two Growatts are cheaper than one Eg4 18kPV or Sol-Ark 15k, and would give you 20kW, and be close to the 22kW of your Generator.

From a cost perspective, I would go with Two Growatts, and leave room for a 3rd, just in case, or for backup (if one goes down, you take it off-line, and you still have 20kW).

The Sol-Ark 15k is the most mature product, but two would be the most expensive.

Two Midnite Solar 10kW would be a nice choice too. All the smartload ports, and a good reputation.

18kPv does not have any advantage (not the cheapest, not the most mature, not the best quality (decent, but not the best), etc.).