WattSaver for Octopus Energy

Now free! Cheapest-slot scheduling, live grid/battery/solar via Home Assistant, Predbat plans and a Today widget for iPhone, iPad and Mac.

WattSaver helps Octopus Energy customers find cheaper times to run appliances, charge devices, and plan around changing electricity prices.

Pick what you want to run, set how long it takes, and WattSaver scans the available half-hour slots to show the best start time and estimated cost. It works with Octopus import and export tariffs, including Agile, Tracker, Flexible, Intelligent Octopus Go, and compatible smart tariffs.

Connect your Octopus account to auto-detect your tariffs, or choose a product and tariff manually if you just want to explore prices before switching.

Key features:

• Find the cheapest time to run any appliance
• See today and tomorrow's half-hour prices
• View smart meter usage by day, week, month, or year
• Compare usage, cost, export profit, and net value using the tariffs active at the time
• Compare import and export rates
• Use scheduling constraints such as earliest start, latest finish, delayed start, and finish-by times
• Save device templates for quick recall
• View price history with colour-coded highs and lows
• Get optional notifications when selected rates are published
• See Intelligent Octopus Go cheap slots where available
• Use WattSaver on iPhone, iPad, Mac, and Apple Watch

Predbat support: If you use Predbat, WattSaver Pro can import your Predbat plan page and use that plan data alongside Octopus prices. Imported Predbat data can be shown on charts and can help scheduling prefer battery charging windows, excess solar, or peak solar periods where your plan includes those signals.

WattSaver does not measure your solar generation or battery state directly. Predbat solar, excess solar, and battery information is read from the Predbat plan URL you provide.

Free features include basic scheduling, current prices, and one saved template. Some advanced features require the one-time WattSaver Pro purchase.

WattSaver is an independent app and is not affiliated with Octopus Energy or Predbat.