Report of General Monthly Meeting by Zoom - Tuesday 11th January 2022

 

Electricity - by Michael Etherington

 

A bright spark generating interest

 

The continued desire for man to make life easier of himself was the theme of the talk by Michael Etherington at the January meeting of Winchester u3a. From the moment man learnt to use a bone as a weapon (think 2001 – A Space Odyssey) through using an ox to pull a plough, man has used machines (in the very basic sense of the word) to ease his daily struggle for survival by performing jobs that he couldn’t do unaided. Michael picked up the story from when the first windmills were used to grind corn; they then gave way to the more reliable water mills. Eventually the discovery that burning wood and then coal could be used to make steam, which in turn could be used to move pistons which in turn themselves could be used to rotate wheels and thereby even more complex machinery, provided the platform for the industrial revolution.

 

We learnt how Britain led the way in developing yet more mechanical machines that in turn required more power. Stationary steam engines developed into mobile steam engines on the railway, steam turbines proved much more efficient in their use of coal and the standard of living of most British people continued to rise.

 

Quite separate from this, simple batteries were being developed that could produce a small continuous electric current. By chance it was discovered that a wire with an electric current flowing through it could be affected by a magnet held nearby. By altering the layout and shape of the magnet and the wire, a rotational effect could be produced and eventually a simple electric motor was constructed. To begin with, this was just a novelty with no obvious application as the source batteries were themselves of quite low output. However, it was noticed that instead of making the current turn the wire, turning the wire could produce a current. Mixing the reliable steam engines that were now available with more and more wires looped together generated a continuous and much larger current and that in itself could be used to power a wide range of electrical devices.

 

As the decades and centuries passed, the efficiency of generators improved along with the range of fuels that could be used to produce the energy for turning the armature. As well as burning fuel to produce steam, be that coal, gas, oil or nuclear rods, the rotating motion can be generated from wind or flowing water (be that rivers, tides, waves or pumped storage). More recently the photoelectric conversion of sunlight directly to electrical energy has proved very popular. For a live website showing the hour by hour mix of generation of electricity in the UK, go to gridwatch.co.uk; it changes significantly on a windy day!

 

The demand for electricity isn’t of course uniform through the day and Michael touched on the subject of electricity storage. From pumped water systems (Dinorwig is a great example – do visit it one day if you can) via battery backup systems powering whole factories to flywheels and electric car batteries, there are many solutions that give the National Grid options to supply all its customers wherever and whenever the need arises.

 

Michael is certainly a live wire with the capacity to generate us a further electrifying talk next year.

 

Vernon Tottle

 

02/22