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 electricity and gas usage by day, week, month, or year
• See live demand and same-day usage with an Octopus Home Mini
• Compare usage, cost, export profit, and net value using the tariffs active at the time
• Compare one period against another, such as the previous week or the same month last year
• 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
• See Intelligent Octopus Go smart charging slots, and get alerted when Octopus schedules bonus cheap slots (iPhone and iPad)
• Get optional notifications when selected rates are published (iPhone and iPad)
• Add widgets showing live readings, today's totals, and current electricity and gas unit prices
• Use WattSaver on iPhone, iPad, Mac, and Apple Watch

Home Assistant, solar, and battery support: If you run Home Assistant, WattSaver Pro can connect to it and show live grid, home, solar, and battery power, plus battery charge, in its Live views and widgets. If you use Predbat, WattSaver Pro can also import your Predbat plan and use it alongside Octopus prices — showing charge, discharge, and solar windows on charts, and helping scheduling prefer battery charging, excess solar, or peak solar periods.

WattSaver does not measure your home directly: live readings come from the Home Assistant sensors you choose, and Predbat data is read from the 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, Home Assistant, or Predbat.