Prices and the price cap
Free electricity from Octopus: how the sessions work
How Octopus’s power-up sessions, Postcode Power Ups and Agile negative prices give you free or cheap electricity, and what you need to join.
Edited by Rob Gibbs. Published: . Guidance reviewed: .
Short answer
There are three routes. Saving Sessions “power up” events reward extra use when renewable power is plentiful. Postcode Power Ups give free electricity to customers in certain South East and East England postcodes. And on Agile, the price itself sometimes drops to zero or below. All three need a connected smart meter, and the sessions need you to opt in.
Saving Sessions power-ups
Saving Sessions is run through Octoplus, Octopus’s rewards scheme. “Power down” sessions pay Octopoints for using less at peak times. “Power up” sessions pay for extra electricity you use when the grid has spare renewable power. These power-ups replaced Octopus’s earlier Free Electricity sessions. Once you sign up, you get an email inviting you to each session.
Postcode Power Ups
Postcode Power Ups are local events in areas run by the network operator UK Power Networks, currently in South East and East England. To take part you must:
- Live in an eligible postcode and be an Octopus customer.
- Have a smart meter that has sent at least 80% of half-hourly readings over the previous 20 days.
- Opt in to each event through the invitation email before it starts.
How you get the credit
Your bill is calculated as normal, then Octopus credits the free electricity used during each Power Up to your account, usually within a few weeks. If you are on Intelligent Octopus Go, your charging schedule does not change automatically, so to charge the car during a Power Up you need to start and stop the charge yourself.
Agile: when the price itself goes negative
On Agile Octopus, a half hour’s price can fall to zero or below when wind and solar output outstrips demand, which means you are paid to use electricity. No opt-in is needed: the price applies to everything you use in that half hour. This site tracks every negative-price event as it happens.
Questions people ask
Do I need a smart meter for free electricity?
Yes. Sessions and Agile prices are worked out from half-hourly smart meter readings.
Is Agile free electricity the same as a power-up?
No. Agile negative prices are part of the tariff and apply automatically. Power-ups and Postcode Power Ups are separate events you opt in to, open to customers on other tariffs too.
Tariffs in this guide
Related guides
- Is Agile Octopus actually cheaper?When Agile Octopus beats a standard tariff, why the answer depends on when you use power, and how to check with your own half-hourly data.
- Octopus EV tariffs without a drivewayWhether Octopus Go or Intelligent Go can work if you have no driveway or home charger, and what to compare instead.
- How to see and download your smart meter dataWhere to find your half-hourly smart meter data from Octopus: in the app, through the free API, and with this site’s private usage tools.
- A home battery without solar on Octopus: does it pay?How a home battery without solar panels can save money on Octopus by charging cheaply overnight, and what to check first.
- The energy price cap now: what it means for Octopus customersThe current Ofgem price cap, what it limits, and how it affects Octopus Flexible, fixed and smart tariffs, updated from Ofgem’s published figures.
- SMETS1 vs SMETS2 smart meters: what is the difference?How SMETS1 and SMETS2 smart meters differ, why it matters when you switch supplier, and what it means for Octopus smart tariffs.
Primary sources
- Saving Sessions — Octopus Energy; checked 2026-10-30. Power-down and power-up sessions, Octoplus membership and Octopoints.
- Octopus Postcode Power Ups — Octopus Energy; checked 2026-10-30. Postcode Power Ups eligibility, opt-in, smart-meter data threshold and account credit.
- Smart Tariffs terms and conditions — Octopus Energy; checked 2026-08-24. Smart-tariff eligibility, rate windows, compatibility and publication caveats.