Octopus Greener Days – Green Overnight Energy

Octopus Greener Days – Green Overnight Energy

The Octopus Greener Days overnight forecast (23:00–06:00) helps you plan EV charging, appliance use, or battery top-ups for the hours when renewable electricity peaks on the UK grid.

By shifting your energy use to these cleaner periods, you can lower your carbon footprint — and on certain tariffs, save money or even earn small rewards.

What Is Octopus Greener Days?

Octopus Energy Greener Days is a free forecast for all Octopus customers with a smart meter, showing the overnight periods when renewable electricity is most abundant.

The forecast runs seven days ahead and gives each night a Greenness Score (0–100), based on predicted renewable generation.

You’ll see the crown icon for especially green nights (when viewing through through your Octopus account), helping you decide when to plug in.

How the forecast is calculated

The Octopus green energy forecast is based on:

• National Grid data

• Renewable generation predictions (wind, solar, hydro)

• Grid carbon intensity

For each overnight period, Octopus assigns:

• Greenness Score (0–100) – higher = cleaner energy

• Highlight flag – marks the greenest nights

• Index ranking – orders nights from greenest to least green

Example:
A 90/100 score could mean strong offshore wind generation and low fossil fuel usage — the perfect time to run big appliances.

Developer tip:
You can access the raw data via Octopus’s GraphQL API.

“Greener Days”… really means greener nights

Although Octopus calls it Greener Days, the forecast covers overnight hours only.
In effect, you’re planning to use greener electricity between 11 p.m. and 6 a.m., not during the day.

On Energy Stats UK, we present the greener period as 00:00–06:00 to make this clearer.

Today’s Forecast

We post the latest Greener Days graph to our social media accounts (Twitter / X, Bluesky or Mastodon) daily — alongside Agile Tariff, Tracker Tariff and Outgoing Octopus Export charts.

Make it Work For You

• Check the forecast in your Octopus account or on Energy Stats UK.
• Plan EV charging or appliances for the highest-scoring nights.

When clean nights are cheaper too

If you’re on a flexible tariff like Agile Octopus or Tracker, greener nights often match up with:

• Lower wholesale prices

• Occasional negative rates (when wind generation is high)

That means you could:

• Pay less per kWh (or get paid to use power)

• Earn Octopoints

• Reduce your carbon footprint

On fixed smart tariffs like Intelligent Go, there’s no price change — but there’s still a moral reward for charging when it’s best for the grid.

Pricing for other Octopus Time of Use / Smart Tariffs can be found here: Agile, Cosy, Go, Flux, Intelligent Go, and Tracker.

Where Octopus Greener Days Data Comes From

The data is pulled directly from Octopus Energy’s GraphQL endpoint, showing:

• validFrom / validTo

• greennessScore

• greennessIndex

• highlightFlag

We’ve confirmed the time window is always 23:00–06:00.

You can play with this yourself via this link:

https://api.octopus.energy/v1/graphql/#query=query%20GreennessForecast%20%7B%0A%20%20greennessForecast%20%7B%0A%20%20%20%20validFrom%0A%20%20%20%20validTo%0A%20%20%20%20greennessScore%0A%20%20%20%20greennessIndex%0A%20%20%20%20highlightFlag%0A%20%20%7D%0A%7D&operationName=GreennessForecast

You can see in this screen snippet how the data is presented.

You can clearly see the raw data show the time period 23:00 to 06:00.

Hence why I think this should be called Greener Nights/Mornings, not Greener Days.

Octopus Greener Days Score (Next 5 days)

Octopus Greener Days Score versus Agile and Tracker tariffs (last 50 days)

Note: I’ve reversed the scale on the graph for the Greener Days Score to be a negative value to scale better with the lower Agile and Tracker pricing (right hand side)

The Greener Score still shows positive within the graph though.

FAQs About Octopus Greener Days

Do I need a specific tariff?
No. A smart meter is required to view/benefit from the forecast; pricing benefits depend on your tariff.

Is it only for EV drivers?
No. EVs gain the most, but anyone can move high-load tasks to cleaner hours.

How far ahead can I see?
A week ahead, updated daily.

Can I get notifications?
Not from Octopus directly, but third-party apps like Energy Stats UK can send alerts.  Subscribe to their social media accounts on Twitter / X, Bluesky and Mastodon.

Why is it called “Days” if it’s at night?
Marketing choice — but it’s really about the overnight period when the grid is greenest.

Where to Check the Octopus Greener Days Forecast

• You can find the official forecast by:

  • Logging into your Octopus Energy account

  • Using the Energy Stats UK Greener Days website

  • Accessing Octopus’s GraphQL API for developers

Final Thoughts

Timing usage for cleaner overnight hours is an easy win: fewer emissions, potential savings on flexible tariffs, and small rewards for some users.

By checking the forecast and planning your overnight charging, you can:

• Lower your carbon footprint

• Possibly save money on variable tariffs

• Earn small Octoplus rewards

Switch to Octopus Energy, get £50 free credit – and start charging greener.