But if you already have a substantial PV setup, and you're within shooting distance of providing power to cover your own use, it may be come worth it to expand

But if you already have a substantial PV setup, and you're within shooting distance of providing power to cover your own use, it may be come worth it to expand (or decrease your use) if you're faced with paying $1536/year (128 * 12) just for being connected to the grid.