10 things you may not know
about local electricity networks

1. 

   Electricity comes from power stations via the high voltage electricity network (‘the motorway’) and then gets ‘transformed’ to lower voltage at substations before coming into people’s homes via the ‘local’ low voltage electricity network (‘the A & B roads’).

2. 

   Approximately 800,000 kilometres, or half a million miles, of overhead and underground power lines make up the low voltage distribution networks in Britain (more than the distance to the moon and back).

3. 

   There are approximately 230,000 ground-mounted distribution substations nationally. In addition there are approximately 349,000 pole-mounted transformers (these are ‘mini-substations’). So there are around 579,000 ‘substations’ in total.

4. 

   Feeders carry electricity from substations to our homes. Great Britain has about a million low voltage feeders. The pole-mounted transformers tend to supply one feeder (but sometimes two), and the ground-mounted distribution substations supply 3 – 4 feeders on average, but in urban areas this could be as high as 10 or 11.

5. 

   The basic units for measuring electric power are watts, kilowatts (1,000 watts) and megawatts (one million watts).

6. 

   Energy from electricity is generally measured in kilowatt hours, megawatt hours and gigawatt hours (kWh, MWh and GWh).

7. 

   A kWh equates to the use of 1,000 watts of electricity for a full hour, or ten 100 watt light bulbs all lit for a full hour.

8. 

   A MWh equals 1,000 kilowatt hours – enough to supply the average power requirement for around 2,000 homes for an hour.

9. 

   The average household uses around 3,300 kWhs of electricity per year.

10. 

    The WPD Electricity Network delivers power to 7.8 million customers over a service area of 34,000 miles or 55,000 sq km.