TV pickup

From Wikipedia, the free encyclopedia
Jump to: navigation, search
TV pickup is caused partly by the simultaneous mass use of electric kettles

Television pickup is a phenomenon that affects electricity generation and transmission networks, often occurring when a large number of people watch the same TV programmes while taking advantage of commercial breaks to operate electrical appliances (particularly kettles), thus causing large synchronised surges in national electricity consumption. Electricity networks devote considerable resources to predicting and providing electricity supply for these events which in the UK for example, typically impose an extra demand of around 200–400 megawatts (MW) on the Grid. Short term supply is often obtained from pumped storage reservoirs, which can be quickly brought online, backed up by the slower fossil fuel and nuclear power stations. The largest ever pickup was on 4 July 1990 when a 2800 MW demand was imposed by the ending of the penalty shootout in the England v West Germany FIFA World Cup semi-final.[1][2] In addition to pickups the Grid also prepares for synchronised switch-offs during remembrance and energy awareness events.

Cause[edit]

TV pickups occur during breaks in popular television programmes and are a surge in demand caused by the boiling of kettles and the opening of fridge doors by millions of people.[2] The phenomenon is common in the UK where individual programmes can often attract a significantly large audience share.[1] The introduction of a wider range of TV channels is mitigating the effect but it remains a large concern for the National Grid operators.[1]

There are typically several large peaks in energy use caused by TV pickup during each day dependant on TV schedules, the day of the week and weather.[3] The largest pickup of the day is usually at 21:00 when several popular TV programmes end or go to commercial breaks.[3] The most popular programmes, hence those giving the greatest pickup are soaps, sporting events, and reality TV. A typical TV pickup imposes an extra demand of 200–400 megawatts with larger soap storylines bringing around 700–800 MW.[1]

Response[edit]

A sudden increase in demand, unmatched by an increase in supply, causes a drop in the mains frequency across the Grid (locally the voltage may also be affected due to changes in reactive power flows).[4] The National Grid Energy Balancing Team is responsible for ensuring an adequate supply of electricity and try to ensure a frequency of between 49.5 and 50.5 Hz is maintained.[3][5] In order to prepare for pickups they run a computer program that compares the current day with corresponding periods over the past five years to predict the size of demand.[1]

Diagram of a typical pumped storage power station

It is important to predict demand as precisely as possible as electricity grids are not capable of storing electricity in large quantities and all power stations have a lead-in time before generation can begin.[6] Balancing teams attempt to meet short term fluctuations with "fast reserves" that are quick to come online, backed up with longer term fossil fuel-based "balance mechanism units".[3] The shortest lead-in times are on pumped storage reservoirs, such as the Dinorwig power station that has the fastest response time of any pumped storage station in the world at just 12 seconds to produce 1320 MW.[6] Once the longer term fossil fuel stations, which have response times around half an hour, and nuclear power stations, which can take even longer, come online then pumped storage stations can be turned off and the water returned to the reservoir.[6]

Records[edit]

The largest TV pickups recorded in the UK are:

Pickup demand Date Programme
2800 MW 4 July 1990 England v West Germany FIFA World Cup semi-final penalty shootout[1]
2600 MW 22 January 1984 The Thorn Birds[1]
2570 MW 21 June 2002 England v Brazil FIFA World Cup quarter-final[1]
2400 MW 29 April 2011 Wedding of Prince William and Catherine Middleton[7]
2290 MW 5 April 2001 EastEnders[1]

Other events can cause even bigger pickups for the National Grid than television events. Immediately following the solar eclipse of August 11, 1999 there was a record demand of 3000 MW.[8]

International football finals are a particular problem as research has shown that 71% of people in the UK will watch them at home instead of public venues such as pubs.[2] The UK National Grid had predicted a pickup of around 3000 MW, equivalent to 1.2 million kettles being turned on at once, if England made the later stages of the 2010 FIFA World Cup.[2][9]

The Grid also plans for the opposite effect, a co-ordinated mass switch-off of appliances. At midday on 5 January 2005 a three minutes silence in remembrance of the Boxing Day Tsunami resulted in a 1300 MW temporary drop in consumption followed by a sudden 1400 MW rise.[10] Similar, though smaller, switch-offs occur annually at 11 am on Remembrance Day.[1] These switch-offs occur during the day time, so they are smaller than pickups seen at night when more electrical appliances are likely to be in use.[1] National Grid argued against the mass switch-off originally planned for the Live Earth and Planet Aid events as these would have resulted in highly unpredictable demands for electricity and would have generated more carbon dioxide than would have been saved. These events were subsequently cancelled.[1]

See also[edit]

References[edit]

  1. ^ a b c d e f g h i j k l "Can you have a big 'switch off'?". BBC News. 6 September 2007. Retrieved 31 October 2010. 
  2. ^ a b c d "National Grid anticipates power surges during World Cup". The Daily Telegraph (London). 11 June 2010. Retrieved 31 October 2010. 
  3. ^ a b c d Easton, Nick. "A Day in the Life of an Operational Energy Manager". National Grid Transco. Retrieved 31 October 2010. 
  4. ^ "Notes for guidance". National STEM Centre. Retrieved 6 November 2010. 
  5. ^ "Balancing Services Open Day". National Grid. Retrieved 6 November 2010. 
  6. ^ a b c Darvill, Andy. "Pumped Storage Reservoirs: Storing energy to cope with big demands". Retrieved 31 October 2010. 
  7. ^ "Royal wedding: In numbers". BBC News. 1 May 2011. Retrieved 2 May 2011. 
  8. ^ "BBC News: Eclipse sparks record power surge". BBC. Retrieved 10 July 2012. 
  9. ^ "News Roundup for June 14". Electric Co-op. Retrieved 6 November 2010. 
  10. ^ Batsone, Dorcas. "Introduction Seminar –ELEXON, the BSC arrangements and the electricity industry". Elexon. Retrieved 31 October 2010. [dead link]