Balancing act: how the National Grid manages demand

Balancing act: how the National Grid manages demand

15 August 2019

Remember this scene? It’s the semi-final of the 2018 World Cup, and England are about to head into extra time against Croatia.

Nerves across the country are a mess, especially yours. You probably nipped to the kitchen for a cup of tea, or poked your head into the fridge for a cold drink. Maybe a quick trip to the loo before the action restarted? Little did you know at the time that the nation was a mere half-hour away from heartbreak.

But as you reflect on the torturous suspense and agony of crashing out of the World Cup, spare a thought for the folks overseeing the National Grid, who were contending with a few nervy moments of their own. While you were putting the kettle on and nipping to the loo, so were millions of others, causing huge spikes in energy usage across the country at precise moments. It’s a problem that the Grid has had to grapple with for years.

National Grid Usage

During popular programmes on TV, or specifically during their interims or ad breaks, the National Grid finds itself under a surge of extra strain as people use their appliances in almost perfect synchronisation. The phenomenon, known as a TV pickup, is unique to the United Kingdom, and requires electricity networks to pull in extra resource as they prepare to cater for the anticipated jumps.

If you were wondering why such a phenomenon is unique to these fair isles, it’s rooted in our love of a cup of tea. Most electric kettles, which are the norm for British households, typically use between 1,000-1,500 watts of energy, and for a small appliance that’s quite a lot. Now, imagine millions of those kettles being switched on at the same time. This is where TV pickup comes from, and the use of additional appliances at the same time only adds to the pressure on the grid.

Someone pouring water from a kettle to make tea

How does the National Grid balance?

So how exactly is the National Grid put under such pressure, and how are these surges predicted? A sudden increase in demand, unmatched by an increase in supply, causes a drop in the mains frequency across the Grid. So the National Grid Energy Balancing Team, who are responsible for ensuring an adequate supply of electricity, have to run a computer programme that compares the current day with corresponding periods over the past five years to predict the size of demand. They then notify power stations of a recommended ‘lead in time’, which would enable them to prepare for - and cover - the extra need for electricity.

Modelling via a computer algorithm isn’t enough to predict future surges. Grid employees themselves have to study TV schedules to anticipate demand. Big sporting events are easy to identify as potential risks, but in some cases it isn’t so straightforward. Operators often have to familiarise themselves with popular soap-opera storylines or upcoming TV dramas, as one might cause a sudden rise in usage. The dastardly deeds of Phil Mitchell can often have a profound impact on a Grid worker’s day-to-day.

The good news is that, according to the National Grid, changing viewing habits nationwide are bringing along some respite. The rise of on demand streaming services, such as Netflix and iPlayer, means that millions of people are much less likely to nip to the kitchen for a cup of tea at the same time. That said, the surges are still an issue for major events such as the World Cup. In fact, all of England’s knockout games at the last tournament ranked as some of the highest TV pickups in recent memory, so the Grid still needs to be equipped to serve the country during spikes in activity.

Still, the reduced urgency of watching television by means of ‘appointment’ gives the Grid a little breathing space. And with a bit more breathing space, our friends on the Grid have a bit more time to relax. Cup of tea, anyone?