As World Cup fever grips the country, National Grid is preparing to deal with a series of extraordinary phenomena associated with big sporting events on television.

TV pick-ups – the huge surge in demand for electricity at the end of a game as viewers get out of their seats and switch on lights, open fridge doors for a cold drink and boil kettles for a cuppa – are being anticipated throughout the tournament by the company’s team of expert forecasters.

And this is where you’ll be able to find out what we’re predicting this year and what actually happens.

The biggest ever TV pick-up – which we measure as a kettle count – was following the penalty shoot-out at the end of the 1990 World Cup semi-final between England and West Germany – that’s the one in which Gazza cried.

The chart below shows UK electricity demand before, during and after the match, which kicked off at 7.00pm.

World Cup 1990 Semi-Final, England vs West Germany, 4 July 1990

At kick-off, demand dropped from just under 30GW (30,000MW) to less than 28GW as fans settled down in front of the television. At half time it rose by 1,600MW – equivalent to 640,000 kettles all being switched on at once.

There were similar spikes in demand at full time and at the end of extra time.

But the biggest pick-up that evening took place at about 10.00pm after the penalties, when demand soared by a record 2,800MW – equivalent to 1,120,000 kettles being switched on at once!

National Grid’s energy analysts forecast the UK’s electricity demand minute-by-minute and day-by-day to make sure there’s enough generation available to allow us to balance the electricity transmission system.

And this year, they're predicting that the record pick-up could be beaten by a surge of 3,000MW – if the England team reach the final and it also goes to penalties.

Being able to predict when surges in demand for electricity are likely to happen is important because the UK electricity system operates at 50Hz – 50 cycles per second – and if demand outstrips supply, that figure will drop and electrical machinery and equipment may not operate correctly.

The analysts take into account the time of year, the day of the week and the weather, as well as television schedules. And it’s not just the end of big sporting events that cause TV pick-ups, the end of popular soap episodes during major storylines also have the same effect.

In National Grid’s Electricity National Control Centre, engineers use the energy analysts’ forecasts of TV pick-ups to predict when it may be necessary to bring on more generation to ensure the 50Hz level is maintained and the electricity system stays balanced.