Time-of-use + batteries: a Stockton case study
A Stockton family paired a 2× Powerwall with TOU-aware scheduling. Case study on the system design, the load profile, and the documented operating results.
A Stockton family moved their PG&E account to TOU rate scheduling and paired it with a 2× Powerwall. Here is the math, the schedule, and the lessons we drew from it.
The setup
2.4 kW south-facing solar array, 2× Tesla Powerwall 3 (27 kWh total), E-TOU-C rate plan. Their original account ran on a flat E-1 rate. We re-papered them onto E-TOU-C at the start of the project.
The schedule
Solar charges the batteries from 9 AM to 3 PM. From 4 PM to 9 PM — PG&E peak window — the house runs on battery. Off-peak (12 AM to 3 AM) the grid charges batteries to 100% if solar was insufficient.
The numbers
Annual production: 11,200 kWh. Annual consumption: 14,800 kWh. Annual grid import: 3,600 kWh (off-peak only). Annual grid export: 0 — the array is sized so essentially everything produced is consumed on site.
What we learned
The first PSPS event ran the house for 34 hours without the grid. The family did not notice until we told them. That is the whole point.