"We can tell how much an event is gripping the nation," says Nigel Williams, head of electricity systems operations at the National Grid.
"That frequency is the heartbeat of the nation," says Williams
The hour-by-hour pulse of the electrical signal also reveals how traditional most Brits remain when it comes to Christmas itself.
"People's behaviour always surprises me in that it is so predictable," says Williams
Preventing the nation's fairy lights going out can take 1,000 balancing actions a day, says Williams
, but the increasing use of intermittent renewable energy is not a problem.
"When we first got wind on the grid we had a few choppy days, but we are managing it very well now," he
"Our forecasting is very good."
The grid gets useful wind forecasts 10 days ahead, and 24 hours ahead can predict the amount of electricity that will be generated to within 4%.
Earlier in December, a wind power record was set of 6GW - equivalent to six big power stations and 14% of all electricity at the time - and the grid then managed a 2.5GW dropoff over a few hours as winds surpassed safety limits in many places.
"I don't see an upper limit to how much wind we can accommodate [on the grid]", says Williams
, who also notes that 98% of payments to companies to stop generating when the grid is getting overloaded go to coal and gas, not wind.
, whose charges make up about 4% of electricity bills, has also seen the traditional evening lighting peak lowered by the widespread use of low energy bulbs.
Overall, says Williams
, "we like a nice balanced portfolio of generation sources, so if you have trouble in the Ukraine or a miners' strike, you can deal with it."
said the huge new nuclear power stations being planned would provide significant, stable power but were not essential: "You could do without nuclear as long as you get the volume [of electricity] from elsewhere.
said the much larger size of the new reactors incurred more costs to the grid, as they have to increase the capacity to hand to ensure the network would cope if the reactors tripped offline.
described the recent warnings of blackouts made by energy company bosses as scaremongering.
"We have always had periods when there is a bit of a crunch and we have managed that," he
"People talk about winters of discontent and blackouts, but what we are talking about in the worst-case scenario is a few half-hour periods a year.
It's most likely we'd reduce the frequency a bit, so lights would dim a little and hairdryers would be a little less hot.
Most people would not notice."
While the National Grid
has to anticipate people's behaviour to keep the lights on, in particular predict TV hits, it does not mean its staff always agrees with the audience's choices.
"The TV pickup from Deal or No Deal is gobsmackingly high," said Williams