Live tariff data
Agile is one of the clearest ways to show why a battery pays: the same unit of electricity can cost several times more at peak than overnight. The widget shows that gap with real prices, on your website.
When a visitor opens the calculator, it fetches the last 24 hours of Agile half-hourly prices for your region from Octopus Energy's public API. It then takes the average of the three most expensive hours minus the average of the three cheapest, which is roughly what a home battery can actually move each day.
Using a rolling 24-hour window means the figure always includes an evening peak and an overnight low, whatever time of day someone visits. Single extreme half-hours are not used, because they overstate what a battery can capture.
Visitors who are not on Agile can pick Octopus Go or Cosy, which use a typical fixed cheap/peak gap, or “other time-of-use tariff” and set the gap themselves. The estimate always shows which tariff and assumptions it is based on.
Your company name, colour, logo, phone number and button text are loaded from your account, so you can change them later without touching your site. If the Octopus API is briefly unavailable, the calculator keeps working with the slider value instead of breaking your page.
If your subscription ends, the widget simply stops showing; there is nothing to remove.
Every result is labelled as an illustrative estimate, not a quote. EV charging savings are listed separately and are not counted in the battery's payback period. Sparky Widget is not affiliated with Octopus Energy; it uses Octopus's publicly available price data.
This is the real calculator, branded for a made-up demo installer. On your site it shows your name, colour, logo and phone number.
Demo installer “Bright Spark Electrical” is fictional.
The region you choose in your settings, so the prices match the area you install in.
Every time the widget loads, it fetches the latest 24 hours of Agile prices.
No. It is an independent tool that uses Octopus Energy's public tariff data.