What are Transmission charges?

Transmission charges, also known as TUoS or TNUoS charges, could be a large part of your electricity bill, often 5-10%. It is important to understand these charges and take control where possible. Manage your demand during the three national Triad periods, or risk receiving large bills as a consequence.

What are Triads?

In the UK, National Grid determines the three highest half hour periods of demand during the winter months. These are termed “Triads” and are used to calculate your Transmission charges.

To be recognised as a Triad these three half hour periods must:

Fall between 1st November and 28th/29th February
Be separated by a clear window of at least ten days

If you are charged for Transmission separately, your average demand during the three Triad periods is multiplied by your regional tariff to determine how much you pay each year.

The Triads are only announced at the end of the season by National Grid, normally in late March or early April. Transmission charges are estimated during the season and then reconciled after the Triads have been announced.

Triads TNUoS

How our Triad Reporting will help you

In Season

Stark ID’s In Season Predicted Triad reports analyse national data as we progress through the season. It then highlights when a Triad is likely to have occurred. Using these estimated Triads, we calculate your likely exposure and show how well you have performed so far.

End of Season

Once National Grid has published the official Triads, Stark ID’s Actual Triad reports enable you to review your performance and annual TUoS charges, before your electricity supplier reconciles your bill.

With our Triad reports you can:

  • Analyse Transmission costs across your whole portfolio or drill down to a single meter – even rank your sites to determine where to focus first
  • Review your performance during expected Triad days and evaluate whether you have successfully managed your demand
  • Predict your final Transmission charges based on the expected Triads and visualise your exposure (even if you are not currently charged for this cost separately)