Adding batter to existing grid tie

[robosolar]

I have 4.8Kw grid tie with demand monitor and control. We set demand control as 5.5kw; between 6-8pm, there seems to be not enough sun and the demand control turn off AC before it reaches to 79 degrees, which is what we set. The room temp is around 82-83 degrees in this time frame. The price for demand charge is around $17/kw with SRP in Arizona. If we set it higher, the cost using solar will be higher than regular plan.
I am looking for a way to boost power between 6-8pm so we can stay comfortable but still get some benefit from solar system.

 

[wpns]

Does your inverter have a manufacturer, and a model number? Does it have any terminals for adding a battery?

 

[robosolar]

Does your inverter have a manufacturer, and a model number? Does it have any terminals for adding a battery?

It's solaredge SE5000H. They quoted me for HD7600 but they installed SE5000H without informing me.

 

[Hedges]

You can consider a StorEdge to replace your SolarEdge.
It would take an expensive (but quality) BYD HV battery, among others.

Or, you can get a battery or hybrid inverter that AC couples to GT PV inverters, preferably with Rule-21 Frequency-Watts enabled on your SolarEdge.
Some do AC coupling better than others.

Backup when grid is down sometimes requires additional hardware.

You can also get AC coupled battery, just for peak shaving. Tesla PowerWall, many hybrids can do it as well.
SolArk, EG4, Midnight The One, SMA.
Some use inexpensive 48V batteries, some more expensive HV batteries.