Duke Energy - 20kW maximum - what's this actually mean?

[see_eo]

I am in the process of designing a system that will handle our household's entire usage - which is quite a bit. We average 115kWh per day with peaks to 135kWh on especially heavy days. The interconnection information for Duke Energy states that there is a maximum of 20kW. I have been considering something like two Sol-Ark 15kW inverters for redundancy and growth, but that would put me at 30kW in total output.

My question is whether Duke is counting the total system potential (30kW), the total system output as configured (based on my panels) or the total kW that I would be delivering back to the grid after consuming what we need (which I assume can be limited in the inverters to 20kW).

Anyone have experience with Duke?

Also to note: I am grandfathered into the current 1:1 net metering (due to a small, existing solar system) until it expires in 2027 and I have to move to something else.

 

[Supervstech]

No, two 15Kw Solaris would put you at 18kW I think. Maybe 24. I’m not sure of the output max, but it isn’t 15. 15 is the max PV power it can use, including battery charging.

 

[Supervstech]

I am pretty sure sol-ark can be configured to limit backfeed.

 

[see_eo]

No, two 15Kw Solaris would put you at 18kW I think. Maybe 24. I’m not sure of the output max, but it isn’t 15. 15 is the max PV power it can use, including battery charging.

According to the specs, it says this:

• Continuous AC Power from PV: 15,000W 62.5A-L (240V)
• Continuous AC Power from Batteries: 12,000W 50A-L (240V)

I assumed that was the output.

 

[dr.diesel]

In Indiana Duke goes by the Inverter rating, not the combined panel rating.

 

[Lt.Dan]

The 15k is capable of selling to the grid at 15k with PV. So yes in Duke Energy's eyes, it is 15k each for a total of 30k.

The 15k is capable of limiting backfeed though.

 

[see_eo]

The 15k is capable of selling to the grid at 15k with PV. So yes in Duke Energy's eyes, it is 15k each for a total of 30k.

The 15k is capable of limiting backfeed though.

I spoke with Duke Energy today.

They said that I can put a bigger inverter than 20k, but that I would need a curtailment letter from the inverter manufacturer.

Is this a normal thing to get? If so, how and where do I find this?

Also, Duke said that I peaked at 20.844kw. Does that mean I can put in 2 sol-ark 18kpvs, curtail the grid side down to 20kw, get the full advantage of the two units on the house side, and deliver 10kw back to the grid - even if I am peaking to my 20.844kw?

 

[Lt.Dan]

I spoke with Duke Energy today.

They said that I can put a bigger inverter than 20k, but that I would need a curtailment letter from the inverter manufacturer.

Is this a normal thing to get? If so, how and where do I find this?

Also, Duke said that I peaked at 20.844kw. Does that mean I can put in 2 sol-ark 18kpvs, curtail the grid side down to 20kw, get the full advantage of the two units on the house side, and deliver 10kw back to the grid - even if I am peaking to my 20.844kw?

I have never heard of getting a curtailment letter from the Manufacturer, maybe an installer stating that they set the curtailment value and locked it out with a password?

 

[740GLE]

Something like programed max output of XX similar to zero export function but allowing some to get back to the grid for net metering function.

Say If his usage peak (25kw) equals the output of the Inverter (25kw) the utility meter will see zero, but if the load is isolated the inverter needs to ramp down to 20kw.

What size service does the house have? Have you inquired how much or what is needed to to increase export beyond 20kw max limit from the utility?

 

[see_eo]

Something like programed max output of XX similar to zero export function but allowing some to get back to the grid for net metering function.

Say If his usage peak (25kw) equals the output of the Inverter (25kw) the utility meter will see zero, but if the load is isolated the inverter needs to ramp down to 20kw.

What size service does the house have? Have you inquired how much or what is needed to to increase export beyond 20kw max limit from the utility?

I’ve got a 400 amp service.

 

[z_zk_z]

I think, the limit is based on the transformer rating at top of the electric pole and the number of homes that are connected to it.

 

[see_eo]

I have never heard of getting a curtailment letter from the Manufacturer, maybe an installer stating that they set the curtailment value and locked it out with a password?

I'm assuming it is by the installer. Which, will be mostly me with an electrician to touch the grid side. I guess he could do the letter.

 

[740GLE]

I’ve got a 400 amp service.

Make sense for that kind of usage.

Your utility will be sad to see the reduction of consumption, you are a heavy hitter.