Every PPA has a yearly escalator — the percent your payment increases annually, anywhere from 0% to 3.9%. Because the payment is the same every month, reps love calling it "fixed" while glossing over the yearly climb. "It goes up no more than 3.9%" means it goes up 3.9% every year.
An escalator isn't inherently bad — a higher escalator buys you the biggest day-one savings of any solar option, and it's still better than the utility's trajectory. But hiding it is disqualifying. Fair San Diego pricing with battery: $0.20-$0.24/kWh at 3.5% escalation, or $0.28-$0.31/kWh at 0%. Dramatically lower quotes usually mean the battery payment is hiding on a separate line. Do the math yourself: total monthly payment ÷ average monthly production = your real $/kWh.