Steven, have a read on this solarquotes blog article . . .
https://www.solarquotes.com.au/blog/three-free-hours-a-tale-of-three-batteries/
Also googles AI response to > making a tesla powerwall 2 discharge to grid at a particular time
In full . . .
To force a Tesla Powerwall 2 to discharge energy to the utility grid at a specific time, you must manipulate the native Time-Based Control settings or use third-party smart home automation tools. The standard Tesla app does not have a simple "discharge now" button, so the system relies on price signals to trigger exports.
Method 1: The Native Tesla App Trick
You can trick the Tesla Support algorithm into dumping battery power by creating a custom utility rate plan with an artificially high "sell price" during your targeted hour.
- Enable Time-Based Control: In the Tesla App, navigate to Settings > Powerwall > Operational Mode and select Time-Based Control.
- Edit the Rate Plan: Go to Utility Rate Plan. Create a custom schedule where your targeted discharge hour is designated as the Peak period.
- Exaggerate the Prices: Set the "Buy" and "Sell" rates for that specific peak hour extremely high (e.g., $2.00/kWh), while keeping other hours low.
- Adjust Export Settings: Go to Advanced settings and change Energy Exports from "Solar Only" to Everything. This permits the Powerwall to push stored battery energy into the grid rather than just covering home loads.
Method 2: Third-Party Automation (Home Assistant)
If you want dynamic, hands-off scheduling without breaking your normal app configuration, you can use local automation software.
- Home Assistant: Connect the Tesla Custom Integration via HACS. You can write a basic automation script that triggers at your specific time.
- The Logic: Have the script change the Powerwall operational mode to Time-Based Control and set Grid Export to Everything at the start hour, then revert back to Self-Powered mode when done.
Method 3: Dedicated Apps (NetZero)
If you prefer a simpler smartphone solution than Home Assistant, the third-party app NetZero pairs directly with your Tesla account. It includes built-in scheduling options that allow you to set rules like "Every day at 4:00 PM, change export settings to Everything" to automate grid dumping.
To see a visual step-by-step guide on configuring the native Time-Based Control features and understanding the app layout, watch this walkthrough:
⚠️ Critical Requirements & Limitations
- Grid Approval (PTO): Your local utility provider must grant Permission to Operate with an agreement that allows battery export. If your utility blocks battery exports, the "Everything" export option will be hidden or non-functional in your app.
- Backup Reserve Limits: The Powerwall will only discharge down to your designated Backup Reserve percentage. If you want a deep discharge, ensure your reserve slider is turned down low (e.g., 20%).
- Discharge Speed: Powerwall 2 will export at its maximum continuous power capability (up to 5 kW per unit). There is no native setting to limit or slow down the discharge rate during a grid dump.
