Help me understand Ohio's net metering (trying to figure out if a battery is worth it)

I signed the contract last week to get solar installed on my roof and I initially declined any batteries. My thinking was that Ohio has 1:1 net metering, so while solar will pay for itself, batteries won't.

But, today I looked at https://www.aes-ohio.com/your-net-metering-bill and noticed that the generation is credited against only the generation portion of the bill, not the delivery portion.

On my current bills, generation and delivery are each about half of the bill, so now I'm thinking that even if I offset 100% of my usage with solar generation I'm still going to pay a delivery charge for power consumed whenever the sun isn't shining. Is that right?

That would mean that batteries will pay for themselves eventually, by allowing me to avoid the delivery charge.

If so, how would I figure out how quickly the battery will pay for itself?

The other thing worth mentioning in my case is that the installer initially quoted me $14k for a 10kWh Ecoflow Ocean Pro system, but today said that ecoflow has a deal going that allows me to do 20 kWh for the same $14k price. That's obviously a better deal, but if the cost per kWH can change by 50% from one month to the next, I have to wonder if either price is a good deal?