Wholesale Energy Pricing & UK Electricity Cost Insights

Introduction: How UK Energy Suppliers Buy Electricity

UK energy suppliers buy most of their electricity in advance through the futures market, a process known as hedging. This allows suppliers to secure energy at an agreed price months—or even a year—ahead, providing security of supply and predictable costs for their customers.

Once the wholesale price is set, suppliers add other costs such as distribution fees and operating costs, then set the tariffs they charge consumers.

This is why wholesale energy pricing directly affects electricity prices in the UK and overall UK electricity cost.

If you want a deeper dive into hedging, Simply Switch has a clear guide here: Business Energy Hedging.

Day-Ahead Electricity Pricing in the UK

While most electricity is bought months in advance through hedging, suppliers sometimes need to purchase extra power closer to real time.

This is where the day-ahead market comes in—suppliers can buy additional electricity for the next day.

Occasionally, cheap electricity is available, and suppliers may “cash in” by purchasing extra at low prices.

I have long been interested in the relationship between the Octopus Agile tariff, the underlying wholesale cost, and day-ahead auction pricing.

To understand it better, I contacted a couple of day ahead auction data providers to see how much it would cost to access detailed wholesale pricing information.

Bearing in mind that this energy-stats website is just a geeky hobby for me, the subscription fees were way out of reach.

You can see single-day UK auction prices here: Nord Pool UK day-ahead prices

Access to historical or more expansive datasets requires a subscription. For example, the Nord Pool Data Portal charges €1,200 per year for up to three users on the BASIC plan.

This challenge led me to explore the process of reverse engineering indicative wholesale electricity prices from the Agile data that is publicly available.

Here’s a graph I came up with showing Indicative Daily Average UK Wholesale Electricity Pricing for the last 2 years:

Indicative Daily Average UK Wholesale Electricity Pricing (last 2 years)

How the Octopus Agile Tariff Reflects Day-Ahead Pricing

The Octopus Agile tariff is a real-world example of wholesale energy pricing in action.

It directly links the tariff you pay to the 30-minute day-ahead wholesale price, making the cost you see reflect the market almost in real time.

For anyone interested in tracking Agile pricing, we provide current and historical data on our dedicated page: Octopus Agile Tariff Pricing.

You can see in this graph from Tuesday 24th June 2025, how 30 minute pricing can fluctuate throughout a single day.

Graphs like these, from Agile and other tariffs, are shared daily on Energy-Stats UK’s social media (Twitter/X, Bluesky, Mastodon), so it’s worth following us to stay up to date.

How the Agile Tariff is Calculated from Wholesale Pricing

The pricing formula that takes wholesale pricing and turns it into Agile pricing has been fully transparent since the Agile tariff started back in 2018.

You can find it here on the Octopus website: Octopus Agile Pricing Explained

The formula basically adds distribution costs, a peak time addition (between 4pm and 7pm) and VAT to come up with the end Agile price that customers pay.

Here’s a step-by-step example:

1. Convert the auction price to pence per kWh
   If a 10am slot is listed at £123/MWh, divide by 1,000:
   £123 ÷ 1,000 = £0.123 (12.3p/kWh)

2. Apply the Agile multiplier
   Octopus multiplies the wholesale price by 2.2:
   12.3p × 2.2 = 27p/kWh

3. Add peak pricing if applicable
   Between 4pm and 7pm, an extra 12p is added. Outside these hours, skip this step.

4. Include VAT
   Multiply the total by 1.05:
   27p × 1.05 ≈ 28.4p/kWh

Using this formula, the 10am £123/MWh slot becomes 28.4p/kWh.

If the same £123/mWh slot was at 5pm (peak time), the Agile price would be 40.4p/kWh.

Important: Wholesale pricing data from Nord Pool (or Epex) is often in UTC, so during daylight saving periods it may be an hour out from UK local time (BST).

Guy Lipman has even more information on the formula showing us the slight differences used between each of the 14 DNO regions: Guy Lipman Agile Formulas

Reverse Engineering Indicative Wholesale Electricity Prices from Agile

To end up with the wholesale cost I had to look at doing the Agile calculation in reverse.

Because we need both Octopus Agile and Octopus Outgoing Agile pricing to account for price caps, I could only go back to May 2019 (when outgoing started).

So I was able to replay my script against all historical Agile data and come up with indicative wholesale electricity pricing for each 30-minute slot.

In this next graph you can see the last 7 days of Indicative Wholesale Price, Agile Import and Agile Outgoing tariffs.

Indicative Wholesale Electric, Agile Import and Agile Outgoing (last 7 days)

Lots of Graphs, Dashboards and Raw CSV Data

I have run the formulas against all the pricing going back to the start of Agile Outgoing in May 2019.

I’ve also written a daily script that updates alongside the Agile data pulls from the Octopus site. These wholesale prices and graphs are updated every day.

The graphs on this page are shown with fixed timeframes. But if you want to explore the data further and see more time periods, head over to the User Configurable Dashboard feature.

You can also download the indicative wholesale pricing in CSV format from the Download Historical Pricing Data page to undertake your own analytics.

Note: Please give credit and link back to energy-stats.uk if you decide to publicly use the data. Thank you.

Other Octopus Energy Time-of-Use / Smart Tariffs you may want to explore are: Cosy, Go, Flux, Intelligent Go, and Tracker.

If you switch to Octopus Energy using my referral link, you can claim £50 FREE credit. Thank you if you do!

Disclaimer

These wholesale figures I have created are provided on a best endeavours basis with no guarantee that they are completely accurate.

They will always be referred to as ‘indicative wholesale pricing’.

The reverse-engineered data is my own creation, based on publicly available Agile pricing and formulas.

FAQ

What is wholesale energy pricing?

Wholesale energy pricing is the cost energy suppliers pay for electricity before adding distribution, fees, and VAT.

How does hedging affect electricity prices?

Suppliers buy electricity months in advance at a fixed price (hedging) to secure supply and mitigate price volatility.

What is the day-ahead market in the UK?

The day-ahead market lets suppliers buy electricity for delivery the following day. Prices can fluctuate each 30-minute slot, which is why wholesale-linked tariffs like Octopus Agile can vary significantly.

What is the Octopus Agile tariff?

The Octopus Agile tariff is a dynamic electricity plan where prices are based directly on 30-minute day-ahead wholesale electricity costs.

How is Agile calculated?

Agile is calculated using wholesale price × 2.2 (multiplier) + 12p peak adjustment (if applicable) + 5% VAT.

Can I track Agile prices in real time?

Yes, historical and daily updates are available on the Octopus Agile Tariff Pricing page.

Where can I access UK day-ahead wholesale prices?

Single-day auction prices are available here: Nord Pool UK day-ahead prices.

Can I access historical wholesale data?

Yes, but accessing extensive datasets usually requires a subscription. For example, the Nord Pool Data Portal charges €1,200/year for basic access.

We have also reverse-engineered indicative wholesale pricing from Agile tariff data.

Indicative Average Wholesale Electricity Pricing for each 30 minute time slot (last 30 days)

Indicative Wholesale Electric Daily Average and Gas / Electric Tracker (last 2 years)