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How to cut electricity bills by tackling Triads this winter

Does your business get half-hourly electricity bills? Act now before the Triad season to minimise costs.

The winter is almost upon us. As the days get colder and the evenings draw in, demand for electricity from businesses and households rises.

To manage this demand, the National Grid uses Triads to encourage businesses to reduce electricity consumption at peak times. It’s important to understand how these work as they can have a big impact on your total electricity bill.

What are Triads?

Triads are the three half-hour periods during the winter that see the highest demand for electricity. “Tri” refers to the three periods, while “AD” stands for average demand.

They can be on any day from 1 November to the end of February. But there’s one condition. They must be at least 10 days apart so that they don’t fall on consecutive days.

What time of day? Triads usually occur between 5.00pm and 6.00pm because that’s when both industrial and domestic consumption tends to peak. But they do sometimes fall outside this window.

How do Triads affect business energy bills?

Triads only affect businesses that get half-hourly bills, mainly medium and large industrial and commercial enterprises.

One of the most significant non-commodity costs on a business energy bill is the Transmission Network Use of System (TNUoS) charge. That’s what you pay to maintain the electricity transmission system in the UK.

Here’s the key point: if you get half-hourly bills, your total TNUoS charge for the coming financial year is calculated based on your average consumption in the three half-hour Triad periods. So if you’re a heavy user of electricity, optimising these costs can make a big difference to your annual spend – the more you reduce your energy usage during Triads, the lower your TNUoS payments will be for the whole of the next year.

But first you need to know when Triads will occur.

Can you predict Triads?

Unfortunately, we can’t predict these spikes in demand with 100% certainty.

That’s mainly because Triads are only determined after the event. Every year in March, National Grid ESO looks back through the season’s data to find the three highest consumption peaks with at least 10 days between each one. So businesses have to wait until spring to find out if they’ve got their forecasting right.

A growing awareness of Triads has also complicated predictions in recent years. The more businesses realise the impact they have on charges, the more they cut consumption in typical peak periods, which affects when they occur. And the increasing use of embedded generation and demand-side response is also levelling out demand.

Changing weather patterns can upset expectations, too. February 2019 was exceptionally warm, so there were no Triads that month. In contrast, two of the three Triads fell in February 2018, as the country was swathed in snow.

How can you cut Triad-related costs?

Despite this uncertainty, there is action you can take to minimise their impact:

  • Sign up for Triad alerts
    Many energy companies offer a service to warn customers of possible upcoming Triads. We offer a free Triad warning service for SSE Business Energy Customers. Drawing on the expertise of energy specialists and weather forecasters, we provide well-informed insights into when the busy periods could be. In both the 2018-19 and 2019-20 Triad seasons, our Triad warning service alerted registered customers before each one. The National Grid also issues warnings when the system is likely to be under stress due to high demand and low generation.
  • Optimise your business hours and energy consumption
    Consider ways to minimise energy usage from the grid for Triad periods. You may be able to switch non-essential machinery or use on-site generation. You could also consider changing your business hours to avoid Triads altogether, if that’s viable. Avoiding Triads can also limit other costs, such as distribution. Triads tend to fall during the most expensive period for Distribution Use of System charges (DUoS), too. Whatever changes you make, you’ll want to do a cost-benefit analysis to make sure possible savings outweigh any costs incurred.
  • Use a Triad management service
    If you’re a heavy user of energy with the ability to reduce demand or use on-site generation, you could use a Triad management service. Our Virtual Power Plant (VPP) includes an automated Triad alert and dispatch service that helps you minimise Triad-related costs. What’s more, VPP can make the most of your energy flexibility, giving you access to new, valuable revenue streams.
  • Treat every day like a Triad
    Regardless of when Triads fall, there are simple ways to cut your energy usage every day. By turning off lights when no one’s in the room or turning down your heating, you’re less likely to be hit by spikes. We offer tools to help you review your business’s energy efficiency, including carrying out an energy audit. Organisations of all shapes and sizes can benefit from taking these simple steps.

What next?

Remember one important caveat as you prepare for winter: Triads won’t be around for much longer.

Ofgem’s Targeted Charging Review has decided that fixed charges are to replace the current Triad charging system. New fixed charging schemes for both transmission (TNUoS) and distribution (DUoS) charges are likely to go live from April 2022.

So if you’re planning to make changes to cut consumption in Triad periods, consider carefully your return on investment. It may not be worth it before they end. On the other hand, reducing your overall energy usage – treating every day like a Triad – will play an even greater role in cutting costs in future.

Whatever you do, don’t be caught out by Triads this winter. Sign up for our free Triad warnings today.


Oliver McMillen

SSE Virtual Power Plant Director

Oliver is responsible for the development and delivery of Virtual Power Plant and Demand Side Response (DSR) related activity within SSE. As part of his role, Oliver works closely with external partners and colleagues to explore new products and services SSE could deliver using the VPP capability. He previously led the Corporate Affairs support – covering policy development, advocacy, and communications – for SSE’s Wholesale business.
View all posts by Oliver McMillen >

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