5.2 What actually changed under NEM 3.0

It's no longer "1:1 netting." NEM 3.0 splits the relationship into two independent bills:

• Buying from the grid: TOU rates of $0.30–0.65/kWh (PG&E E-TOU-C/D, SCE TOU-D-PRIME, SDG&E EV-TOU-5, etc.)
• Selling to the grid: ACC schedule, typically $0.05–0.08/kWh on average, slightly higher during summer evening peak hours

The translation: if your daytime production isn't captured by a battery, every kWh you export only buys back 1/4 to 1/6 of a free evening kWh.

A salesperson will tell you: "Your system makes 12,000 kWh per year and your house uses 12,000 kWh per year, so your bill nets to zero." That math is completely wrong under NEM 3.0. Without enough battery, 70%–80% of your daytime production gets sold to the grid at the cheap export rate while you still pay retail for evening use.