You're assuming that the energy you sell to the power company will be deducted from your usage rate. Maybe you've already checked, but I wouldn't count on it.

What happens if the way they do it is that they see that you consume, on average, 200kWh, and also provide, on average, 75kWh? Your assumption is that they would just bill you for 125kWh. I would be surprised if what they do isn't charge you for 200kWh and then pay you for 75kWh.

Of course, there are still a lot of variables here. You'll still be directly using some (if not most) of the power your PV panels generate, especially since you're looking to use it to supplement AC consumption, which is also going to be used more during the day.

But, again, you are likely going to be selling power to the power company, and you need to see whether they are just going to use that to deduct from your consumption, or if they are going to pay you separately for it.