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Triads 2021/22: this year’s announcement and what it means for your organisation

Posted March 30, 2022

What are Triads?

Triads are the top three half-hourly peaks of national energy demand across the grid, separated by ten clear calendar days, over the most energy intensive period of the year: November to February. National Grid confirms these peaks after the season, at the end of March.

Typically, triads occur when high business demand meets the domestic mid/late afternoon tea-time period, causing an overall spike in energy use.


How Triads impact your energy bill

To manage the huge demand on the network during the triad periods, the National Grid imposes a Transmissions Network Use of System (TNUoS) charge. This is used to finance the maintenance of the UK’s electricity grid to ensure future supply. Impacting customers with half-hourly meters, the charge is proportional to a business’ energy use over the triad periods (the three half hours of highest demand) and is linked to their location. If a business doesn’t consume electricity in the three Triad periods, they don’t pay HH (half-hourly) TNUoS charges for the entire financial year.

As standard, we include a charge for 85% of your maximum demand figure for TNUoS on our customer bills. After the final triads are announced, we issue the March invoices to show the triad periods and make any reconciliations.


The Triad challenge

To mitigate against Triad costs, companies and suppliers work hard to predict when they’ll be so they can turn down or off their energy usage during those periods. Due to the increasing use of Triad avoidance schemes as well as flexibility solutions, such as Demand Side Response and the growing use of renewables, they are getting harder to predict.


The Grid confirmed the three peaks at:

  • Thursday 02-Dec-21 from 16:30-17:00 with peak demand at 43,748 MW

  • Wednesday 05-Jan-22 from 17:00-17:30 with peak demand at 42,760 MW

  • Thursday 20-Jan-22 from 17:00-17:30 with peak demand at 43,538 MW


Our Triad results

To support our customers, we have a team of energy experts with complex modelling and forecasting tools designed to determine when triads will likely be.

EDF predicted and issued alerts for all 3 triads successfully. Any customers on our Triad Alert Guarantee (TAG) service or those who receive Triad alerts via Market Insight will have benefitted from our forecast.

By forecasting and reacting to expected Triads, you avoid costly peak charges. You also help the Grid during periods of high demand. 


Here are some of the factors our team takes into consideration:

Temperature overview

Temperature is one of the most important factors that influence electricity consumption during winter.

The season began with November slightly below normal on average, followed by a cold spell late November to early December. December on average was milder than normal reaching 13°C around Christmas. On average January was comparable to normal whilst February was notably milder ~1.5°C above normal.


Wind speed overview

Wind can have a significant impact on the UK transmission demand and therefore timing of triads.

On average wind was below normal for November through to January until the arrival of storms Dudley, Eunice and Franklin brought high wind speeds throughout February, reducing transmission demand.

Find out more on Market Insight

Free online energy market intelligence for EDF large business customers so you’ll always have the latest information at your fingertips.

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