News / It’s Triad season: What you need to know 2020/21

It’s Triad season: What you need to know 2020/21

11th December 2020

Triads incentivise heavy commercial and industrial users of electricity to shift their power use to periods of lower demand, by charging a premium for high consumption at certain times.

Every winter, the system operator National Grid ESO retrospectively calculates the Triad periods by analysing the settlement data between November and February. The three half-hour periods that are clearly separated by ten days which see the highest demand for electricity across the UK’s energy network are the Triads.

These periods form the basis of Transmission Network Use of System (TNUoS) electricity charges for consumers on half-hourly metering. For Haven Power customers on flexible (pass-through) contracts, your energy consumption during the Triad periods will determine your TNUoS charges.

Because of this, it’s worth avoiding Triads where possible, as energy use at these times can be costly.

The cost of Triads

Discrepancies between what generators produce and the consumption that suppliers forecast can lead to occasional power imbalances. This can happen through over- or under-forecasting supply and demand, or from buying power that remains unused. These differences are reconciled on a half-hourly (HH) basis, in what are known as “settlement periods”.

They typically fall between 5-5.30pm - settlement period HH35 - as business energy demand dovetails with increased domestic demand.

Triads aim to disincentivise heavy energy use at these times of system stress. The cost will depend on your average consumption and your Distribution Network Operator (DNO). The average £/kWh for 2020/21 is £49.56, but varies depending on region.

In Triad season, your HH tariff is multiplied by your average demand during the three half hour Triads.

Look at the table below to see how this would look in practice.

Triad 1 Triad 2 Triad 3
Consumption (kWh) 2,000 3,000 5,000
Time (hours) 0.5 0.5 0.5
kW = kWh/hours 4,000 6,000 10,000

(Triad 1 + Triad 2 + Triad 3) divided by three gives an average demand of 6,666.66 kW. In this scenario, this user would be billed for this volume of 6,666.66 kW.

For the latest period, 2019-2020, the Triads occurred on the 18th November, 2nd of December and 17th of December.

National Grid ESO publishes historic Triad data going back five years. While these are a useful reference point, they are not a definitive indication of future Triad periods. Forecasting services aren’t provided by National Grid ESO.

Understanding Triads in 2020

It’s historically been possible to predict with relative accuracy when these three ‘super peaks’ in demand are likely to happen, though the impact of COVID-19 on the energy network has created a great deal of uncertainty this year.

The severe impact of COVID-19 on the energy system - reduced demand and increased renewable generation - caused balancing costs to increase significantly. This cost - Balancing Services Use of System (BSUoS) - is one of the main non-commodity costs on energy bills and is likely to increase significantly over the next few years.

The second national lockdown - following closely after regional measures, and likely to be replaced by further regional measures in areas of the country still impacted by coronavirus - means a similar drop in demand, and similar consequences for the energy market. These measures may mean that demand is reduced over the Triad season, making modelling and forecasting more difficult than in previous years.

An additional complexity is that the evening peak has become less pronounced in recent years, as heavy and industrial energy users have shifted their consumption to avoid Triad charges. This, along with the complications posed by COVID-19, means that forecasting Triads will be more difficult.

So far this Triad period, November 4th has been a likely candidate for the first Triad. This was one of the coldest days so far in this period, and coming pre-lockdown means that energy consumption is likely to have been higher than on the days immediately preceding and following it.

However, unseasonal weather - as has been the norm over the last few years, as we begin to feel the effects of the climate crisis - may also mirror the spring lockdown, creating further system balancing issues and driving increases in non-commodity costs.

To better understand how COVID-19 has impacted the energy network and what that might mean for your business, download our free whitepaper today.

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