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The snow blows in Triad warnings After a chilly flirtation at the beginning of December, winter finally seems to have arrived this week, with the first widespread snowfall of the […]

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By Geoff Curran

The snow blows in Triad warnings

After a chilly flirtation at the beginning of December, winter finally seems to have arrived this week, with the first widespread snowfall of the season. My guess is that savvy businesses will be firing up any onsite generators, or taking measures to reduce energy demand, as this cold snap looks likely to coincide with a Triad.

I say likely, but to be honest, it’s becoming increasingly hard to tell – and I’ll explain why in a minute.

As you probably know, Triads are the three half-hour periods of peak energy demand that fall between 1 November and 28 February each year. National Grid calculates these – but retrospectively, so once the weather starts to warm up, dedicated boffins trawl through all the demand stats against a possible 5,760 half-hour periods to find the three biggest peaks.

Typically, however, Triads occur between 4.30pm and 6.30pm, when industrial activity coincides with domestic tea-time demand, so that narrows it down to a possible 480 half hour periods during Triad season.

Forecasting potential Triads can pay dividends as National Grid bases its transmission network use charges for half-hourly metered customers on electricity consumption during these periods. So for those able to reduce consumption during Triad periods using services such as SmartSTOR, the costs are also reduced. And when we’re talking sums as much as five figures per megawatt, large energy consumers could make considerable savings.

The challenge, however, is calling it right. And various factors now require ever increasing levels of skill to do this.

The first, perhaps unsurprisingly, is the weather. Britain has never been known for its predictable weather – t-shirts in November and snow in April, even May, is not unheard of. But it seems we’re starting to experience more extreme and unpredictable weather events more frequently.

The recent widespread flooding clearly demonstrates this, with huge volumes of rain falling to give the UK its wettest summer ever. Temperatures are also becoming harder to forecast – take December, for example. The first half was chilly with lower than seasonal norms, while the second half warmed up to give us much higher than average temperatures. The year before, November 2011 was the second warmest ever recorded.

So it appears that what used to be one-off weather events are starting to become the norm, yet predicting these is very difficult – just compare longer-range forecasts from several sources and you’ll start to notice even more disparity than ever before.

Along with changing patterns of weather, we’re also seeing changing patterns in the way large consumers use electricity. From April 2012, for example, businesses using extra-high-voltage started being charged according to their consumption during specific time bands. Unsurprisingly, tea-time is a super peak period, so costs the most. It has therefore made sense for many to shift operations to less expensive time periods. As these consumers account for approximately 7% of UK demand, this has had a knock-on effect on overall demand – making Triads a bit harder to predict.

Another factor is the UK’s energy interconnectors – sub-sea power cables that let us share electricity with Ireland, Northern Ireland, France and Holland. If we find we have an excess and another region has some demand, we can export – or import when the situation is reversed. All very sensible, especially as higher volumes of renewable power come on line from less predictable sources such as wind farms. But National Grid now takes account of any electricity imports via the UK’s interconnector network when calculating overall demand to determine Triad periods. And for those trying to predict these in advance, getting timely import information can be difficult.

When it comes to the UK’s energy use, it’s clear the goalposts are shifting. That’s why the team responsible for monitoring demand and predicting Triads at npower is always expanding its forecasting repertoire, skills and contacts. In 13 years, this team has correctly predicted every Triad bar one with its day-ahead Triad Warning Service, while still keeping the number of warnings it issues to a manageable level.

You can find out the potential value of acting on Triad warnings by using our Triad Warning Savings Calculator.

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