- Forecasting the nation’s demand for electricity on the day of the royal wedding has proved to be quite a challenge
- National Grid control centre is anticipating a TV pick-up of 1200 to 1600 Megawatts
- It’s expected that around 400,000 kettles will be boiled in households across the country after the couple have exchanged vows
The Royal Wedding has proved to be quite a puzzle for National Grid’s demand forecasting team thanks to a number of unusual factors around the day making it different to past events.
This small group of experts have a finger on the pulse of the nation, predicting how the behaviour of millions of Britons affects electricity demand. They play a key part in ensuring that, second by second, exactly the same amount of electricity is being generated as is being consumed.
As with all major events, National Grid is developing a forecast for what power demand will be like on the day of William and Kate’s wedding, ready to deal with those surges and drops in electricity demand throughout the day as people alternate between being glued to their television sets and dashing for the kettle during the natural breaks in proceedings.
The forecasting team uses demand data from previous televised events which took place at similar times and on similar days as a basis to predict the pattern and level of demand for upcoming events. But this time the experts have had to “mix and match” from several different days because William and Kate’s wedding isn’t quite like anything seen before.
Double the impact of Edward and Sophie’s wedding
One factor the forecasters have to consider is the size of the effect of the wedding. The largest surge in demand during Charles and Diana’s wedding in 1981 was a huge 1800 Megawatts (MW), equivalent to 720,000 kettles being boiled at the same time. By contrast, the biggest surge for Edward and Sophie’s big day in 1999 was around 750 MW.
Public interest around William and Kate is greater than it has been around more recent royal events, but the forecasting team isn’t expecting the impact on demand to be as big as for Charles and Diana’s wedding, which belongs to a different era. Instead, they have used Edward and Sophie’s more recent wedding as a model, but are forecasting the largest surge to be double the size with the largest surge being between 1200 to 1600MW, around half a million kettles being boiled simultaneously.
The Bank Holiday effect
Another factor the forecasting team have to consider is the underlying demand for the day. Unusually, the day of the wedding is both a Friday and a Bank Holiday. The only examples of demand patterns on a bank holiday Friday are from Good Fridays, but they felt the ‘solemn feel’ of a Good Friday does not fit the ‘happy feel’ of a bank holiday royal wedding.
So the forecast is based on demand on a May Day bank holiday, on which they have mapped a similar pattern for Edward and Sophie’s wedding but adjusted for different service length and an appearance of the bride and groom along with the Queen on the balcony of Buckingham Palace but with the impact doubled. Demand for electricity however on a bank holiday Monday evening is relatively high, as people use this time to get ready to go back to work. As this is not likely to be the case on a Friday, the forecast ends with a typical demand trend of a Saturday evening before a May bank holiday.
National Grid’s wedding forecast - minute by minute
The general pattern National Grid expects to see is that demand for power will rise steadily throughout the morning, but as the televised coverage begins there will be an overall decrease in demand as millions of people watch television rather than pursuing their usual, more energy-intensive, activities. The forecast expects that sudden surges in demand will come after viewers have watched specific moments in the ceremony – Kate’s arrival and procession up the aisle, the couple’s vows, the moment they appear on the steps of Westminster Abbey as a married couple and their appearance with the Queen on the balcony of Buckingham Palace.
It’s thought that after these significant moments in the ceremony, viewers will leave their television sets to switch their kettles on, and this activity results in an increase in demand. The 1,000 MW surge forecasters are anticipating after the exchange of rings is equivalent to 400,000 kettles being boiled.
But it’s expected that the overall demand for power between 10am and 2pm that day will be lower than at that time on a typical May bank holiday, as the British public sit glued to their television sets to watch the eagerly anticipated wedding unfold.
Meeting the Power Surges
Once the forecasters have done their bit, it is then down to the engineers in National Grid’s control centre to ensure that sufficient fast-acting generation is primed and ready to generate at short notice. The best and most flexible generation is pumped storage from North Wales and Scotland which can deliver power very quickly. This will be supplemented by the despatch of a number of coal and gas fired generating units from all around the country. Timing is critical. The control engineers will be closely monitoring events and will instruct an exact amount of this extra output, as forecast, in advance of an anticipated surge.
Andrew Richards, Forecasting Analyst at National Grid, said: “Planning for major events like this is always fascinating – we get a real insight into the behavioural trends of the British public.
“The entire forecasting team at National Grid is proud of the role they play in making sure families across the country can enjoy watching this special day.”
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For further media information only please contact Doranna Widdicks, National Grid Media Relations, on 01926 655373.