Royal wedding = Royally big swings in energy use

One of the big obstacles people always talk about in making the switch from fossil fuels to cleaner energy is intermittency in supplies: that is, the variable nature of sun and wind power. Keeping the lights on gets tricky when your electricity sources are neither steady nor 100-per cent predictable.

But intermittency in demand can pose an equally large challenge. While utilities have come to expect that demand for energy goes down in the middle of the night, when most people are sleeping, they also face unpredictable swings driven by all sorts of other factors. Say, for example, a royal wedding.

In fact, wedding-watchers in the UK last week were responsible for the fourth-highest surge ever in electricity demand related to a television program. When the news channels finished covering the post-wedding procession to Buckingham Palace and returned programming to their studios, National Grid saw a 2,400-megawatt (MW) surge in electricity demand as millions of people went back to, presumably, surfing the internet, making tea and running their washing-machines.

According to National Grid, that surge was “equivalent to nearly a million kettles being boiled at once.”

The top three television-related energy surges recorded in Britain were:

• A record 2,800 MW, set at the end of the penalty shoot-out after England’s World Cup semi-final against West Germany in 1990;
• A 2,600-MW surge after a 1984 episode of “The Thornbirds”; and
• A 2,570-MW surge at half-time during England’s semi-final match against Brazil in the 2002 World Cup.

Last week’s royal wedding saw a number of demand swings during key parts of the televised coverage:

• A 1500-MW drop in demand as Kate Middleton travelled by car to Westminster Abbey;
• A 500-MW drop as Kate and Prince William exchanged vows;
• A 1,000-MW surge as people took a quick break from the proceedings when the service then continued;
• An 800-MW surge as the couple moved to sign the register;
• A 1300-MW drop during the procession through the cathedral and out onto steps followed by the procession to the palace;
• A 2,400-MW surge as live coverage switched back to the studio after the couple reached the palace;
• A 3,000-MW drop across the period when the couple appeared on the balcony and the RAF flew past; and
• A 1,000-MW surge as television coverage finished.

This impact in demand was broadly in line with National Grid’s forecast, although the final surge was larger than expected, reflecting the huge interest in the event. The 2,400-MW surge compares to the 1,800-MW surge seen during Charles and Diana’s wedding, and the 750-MW surge seen during Edward and Sophie’s ceremony.