Netzero - Intelligent Octopus Go Integration

Introduction

Netzero integrates with the Intelligent Octopus Go EV tariff from Octopus Energy. By providing your Octopus API key and account number, you can configure your Powerwall to charge during smart charging slots outside the off-peak window.

This prevents your Powerwall from discharging while your EV charges and maximizes use of cheaper electricity (7p / kWh), even outside the 23:30–05:30 night rate.

Setup

• Ensure you are on an Intelligent Octopus Go tariff and have a compatible EV or charger. Ohme chargers are not currently supported (see note below).
• In Netzero, go to Settings > Utility Rate Plan.
• Enter your Octopus API key from your Octopus account; it starts with sk_live.
• Enter your Octopus Energy account number from bills, emails, or the Octopus app, e.g. A-12A34A99.
• Switch on Automate Intelligent Octopus Go.
• Optionally enable Preserve charge instead of charging up to keep the Powerwall’s charge during a scheduled slot without charging it. You might use this option if you prefer to charge up the Powerwall from solar instead of the grid.

How it works

Netzero periodically checks for scheduled charging slots. When a slot falls outside the off-peak window (23:30–05:30), Netzero sets the Powerwall backup reserve to 100% so the battery charges. Netzero stores and restores the previous backup reserve after the slot ends.

Notes

• If you have existing automations for smart charging slots (e.g. “When vehicle charging starts: Set backup reserve to 100%”), pause or remove them to avoid conflicts. API-based integration is more reliable.
• If a charging slot ends during the off-peak window (23:30–05:30), the backup reserve remains at 100% through the window and resets at 05:30 unless another slot is scheduled.
• If a charging slot is fully within the off-peak window, the backup reserve will not be changed. Most systems will not discharge the Powerwall in Time-Based Control during off-peak hours. If you prefer, you can also add an automation to keep the Powerwall at 100% backup reserve between 23:40 and 05:30.
• If you override the 100% backup reserve while the EV charges, Netzero will not restore the previous reserve to avoid overriding manual changes.
• Ohme chargers are unsupported because the Octopus API lacks their smart charging schedule. This limitation is outside our control. You can instead link the EV charger and add automations to charge up the Powerwall when the EV is charging.
• The Powerwall’s charging rate varies, usually around 1.8 kW per Powerwall in Self-Powered mode, but may be higher in Time-Based Control mode. Utility limits may also affect the rate.

Update: 6-hour smart charging limit

In March 2026, Octopus Energy will introduce a 6-hour smart EV charging limit for Intelligent Octopus Go. Details are available here: Upcoming changes to Intelligent Octopus Go.

Octopus will also be introducing Charge Cap, a new feature that can limit smart EV charging to 6 hours and help avoid charging at peak prices. We would suggest turning this feature on once it’s available.

Independently of Charge Cap, Netzero will add its own protection. During smart EV charging, Powerwall charging will be limited to 6 hours. If smart EV charging exceeds 6 hours, Netzero will automatically switch to Preserve Charge instead of continuing to charge the Powerwall, avoiding charging the Powerwall at peak rates.

Note: The 6-hour timer only tracks smart EV charging slots. If your Powerwall charges during off-peak outside of smart EV charging slots, this will not affect the 6-hour limit.

No action is required to enable the Netzero 6-hour limit. This update will be enabled automatically once the Intelligent Octopus Go changes go live.