Imagining a life without a ready supply of electricity is well-nigh impossible for anybody in today’s developed world. We are surrounded by gadgets that use electricity. Electricity is used in the manufacture of most items in the shops; electricity keeps us warm and lights up our world.
Electricity is not a primary source of energy. An electrical current is created by a flow of electrons, and in some circumstances these currents do, briefly, occur naturally. Man revolutionised his living environment by discovering how to manufacture electricity – first by chemical reaction, in a battery, and later by using magnetic forces to produce a current.
Early Investigations into Electricity
Experiments into electricity went on in a rather haphazard fashion long before the phenomenon was fully understood. Writers in ancient Greece, Rome and Egypt mention electric fish. People knew lightning was electricity; and it amused them to rub pieces of amber to produce sparks and crackles. Investigations continued, and by the end of the 18th century we had electric batteries and knew electrical currents travelled along wires. This knowledge led to the development of various telegraphic devices that enabled messages to be transmitted and received almost instantaneously, all around the world.
The First Generator
One of the many scientists who made valuable contributions to our understanding of electricity was Michael Faraday, who invented the electric motor in 1821 and ten years later, generated electricity for the first time by moving a magnet in a coil. The same basic electromagnetic principle has been used ever since, although generator design has evolved tremendously. Today, generators can be powered by gas, oil, coal, biofuel, solar power, wind or water power, or nuclear energy.
By the end of the 19th century the electric light-bulb had been invented and a few premises had their own steam generator supplying DC electricity. The first widespread application of electricity was for public services. In 1881 the town of Godalming, in Surrey, made history with its experimental street-lighting system, using electricity generated by water power. Prior to that Britain’s streets had been lit by gaslight, but after Godalming’s experiment towns began switching to electric street-lighting – though some retained gas lamps until well into the 20th century.
Electric tramway systems were also set up. Central generating stations started to proliferate, supplying power for public transport during the day and lighting at night; individuals could have their premises wired for electricity if they wished.
The Growth of the Electricity Industry
Up to the first world war, electricity continued to be produced by numerous small privately-owned generating stations. As demand increased this was no longer an efficient business model, and after the first world war the system changed. Regional electricity authorities were established, and systems were linked so that one authority could supply power to another, to meet demand.
In 1925 the Central Electricity Board was created, and shortly afterwards the National Grid was set up. Soon after this, a marketing campaign promoted electricity as the ‘modern’ fuel, to encourage more households to connect to the mains. By the time of WWII it was no longer just the rich who ‘had electricity’, and a wide range of electrical domestic appliances was becoming available – although there were homes that did not get mains electricity until the 1960s or even later.
The electricity industry was nationalised in 1948, and de-nationalised again in 1990. Today, the UK electricity supply sector is a competitive marketplace, largely dominated by international stakeholders.
Mains and Battery Power
We commonly use two different types of electricity. Batteries contain stored electricity which is supplied as a Direct Current (DC) – in other words, the current always flows in the same direction. Mains electricity cannot easily be stored; it is generated to meet demand, and it is supplied as an Alternating Current (AC) – the direction of flow alternates constantly. DC can be converted into AC by an inverter.
In terms of resource usage, generating mains electricity is more economical than manufacturing batteries. However, there are applications where it is not an option. Some equipment, notably electronic devices, can only be powered by DC. AC can be converted into varying or smooth DC, but this is still not suitable for some sensitive electronic circuits which require steady DC. And for many mobile applications, mains connection is impossible. Fortunately, advances in battery technology mean that we now have re-chargeable batteries that are far more cost-effective and environmentally-friendly than traditional disposable batteries.
Although generating sufficient electricity to meet ever-growing global demand has become one of the challenges of modern society – and there is much heated debate over which, of all the energy sources available to us, should be converted into electricity – electricity is one type of energy that most of us could not even contemplate living without.