Triad Season

2020 - 2021

What are TRIADs?

TRIADs are the three half-hours of greatest electricity demand on the National Grid during November to February. They are retrospectively determined by the National Grid to calculate transmission (TNUoS) charges for electricity consumers.

Throughout the year, energy suppliers will typically charge a monthly indicative TNUoS estimate to cover the TRIAD season. Your final average TRIAD demand (an average of the three selected periods) will be multiplied by the TNUoS rate in your area to give your actual charge for the year, and suppliers will apply a reconciliation (positive or negative) for any variance.

TRIADs should be used as an incentive for large electricity consumers to reduce consumption during expected TRIAD periods in order to reduce annual costs.

When do they occur?

The TRIAD season runs between November to February. There must be a clear 10-day period between any two TRIADs.

Previous years have shown most TRIADs occur on a Monday, with none yet over the weekend.

Although they are likely to occur at any point throughout the day, most occur within the 17:00 – 19:00 period.


Last winter they occurred on:

Mon 18th Nov 2019
17:00 - 17:30
Mon 2nd Dec 2019
17:00 - 17:30
Tues 17th Dec 2019
16:30 - 17:00
2019 - 2020 TRIAD dates and times

What is the value?

The cost of TRIADs for consumers varies across the UK dependent on location. On average TRIADs will cost £48/kW, that equates to £96k for every 1 MWh of consumption. It is advised to implement a TRIAD Action Plan to reduce the load of unnecessary equipment at the advised time upon receiving a warning. It should be simple to trigger and considered in full to avoid unintended costs.

When will TRIADs occur and what should I do?

Based on extensive in-house analysis, Optimised Energy will send you TRIAD warnings whenever a TRIAD is expected to occur. We aim to send out no m ore than 10-15 notifications across the period detailing a High or Very High likelihood status. The alert will detail the action that we recommend that you take to minimise your average TRIAD and therefore reduce the value of the final charge.

What is the future of TRIADs?

The structure of network charging (including both distribution and transmission charges) is currently being revised by OFGEM under the Targeted Charging Review (TCR), set to come into force in April 2022. Whilst the future of TNUoS charging is still in discussion, it is looking likely that this will move from the TRIAD model to a fixed charge approach, meaning the opportunity to a void the bulk of these charges will likely exist for only two more winters. If we can do more to help you with this, please contact your Optimised Energy Account Manager.