The Electrical Grid

Flicking a switch to turn a light on is the final step in a long journey to consume electricity.

This story was created for the Google Expeditions project by Vida Systems, now available on Google Arts & Culture

The Electrical Grid by Vida Systems

Various types of power plants generate electricity that is transmitted through a large network of lines, transformers, substations, and distribution lines before reaching the home.

Tesla vs. Edison: the beginning

The electrical system we use today was developed by two men: one considered one of the greatest American inventors and marketers of all time, and the other a brilliant but eccentric Serbian-American genius.

Thomas Edison and Nikola Tesla competed in a “War of the Currents” during the 1880s, each one convinced that their electricity delivery method was the one the world should embrace. 

Thomas Edison

Most famous for patenting the first successful commercial light bulb in 1879, Thomas Edison patented more than 1,000 inventions over his lifetime. Also a businessman, he started many companies, including one of the world’s biggest, General Electric.

Nikola Tesla

Nikola Tesla invented many things that are credited to others, including everything to do with radio. He invented, predicted, or contributed to the development of hundreds of modern technological items, but wasn’t interested in financial gain and died a poor man.

The battle

 During the late 1880s, America was building its ambitious electrical network to service houses and businesses. Edison wanted this network to use his direct current (DC) method. Tesla firmly believed his alternating current (AC) method was safer for consumers.  

Direct current

Direct current, invented and patented by Thomas Edison, is a current of electricity that runs in a single direction. It has a major drawback because it cannot be easily converted to a higher or lower voltage.

Alternating current

Alternating current, invented by Nikola Tesla, reverses the electricity direction a certain number of times per second. Its voltage can easily be converted using a transformer. It’s also cheaper and easier to create current in AC compared to DC. 

Dirty tactics

Edison was extremely threatened over the development of AC and set out to discredit Tesla personally. He created a scare campaign against alternating current, even electrocuting an elephant to prove that it was unsafe. Much of what Edison claimed was untrue.

The winner

Although direct current was initially used by the US electric system, alternating current became the preferred method of delivering electricity to homes and businesses. 

Direct current’s requirement that power plants be located a mile from a home made it difficult to power up rural areas.

Our electrical world

Modern life is surrounded by devices powered by electricity. It has become so entrenched in people’s lives that it’s unfathomable that people lived millenia without it. Electricity pervades almost every aspect of life and dominates how we live within our homes.


The ability to light our homes has been one of the most significant changes to the behavior of humans in a very long time. Before this innovation, humans generally slept and rose with the sun and stayed indoors in the nighttime.


Televisions are often the centerpiece of home life. Thanks to electricity, these devices are found in almost every home in developed countries. People all over the world use television to receive information and news as well as entertainment.


The internet is often referred to as the entire sum of human knowledge in an accessible form. Never before have humans been able to find and share information and keep in contact with each other so easily. Like other life–changing developments, the internet runs on electricity.

Power stations

All power stations run on the same basic principle developed over 200 years ago: spinning wire around very large magnets. 

Changing a magnetic field by rotating a coil around a magnet creates an electrical current that can be pushed through wire and used to power electrical devices. 


Traditionally, power stations burn a fuel like coal to create electricity. The fuel is used to heat water to create steam. The pressurized steam then turns large fans called turbines. These turbines turn the copper wire to change the magnetic field. 

Solar and nuclear

Some large solar farms use the heat from the sun to heat water and create pressurized steam. Nuclear power plants use the heat generated from splitting the atoms of radioactive materials (usually uranium) to heat the water.

Physical force

Hydroelectric power plants use the movement of water (usually rivers) to physically turn the turbines located inside a dam. Wind turbines use the force of the air, mainly wind, to turn the turbines and generate electricity. 

Solar panels

Solar panels don’t use turbines. Sunlight hits the panel and moves electrons inside it. The panel has 2 layers: One accumulates spare “holes” where electrons were before sunlight moved them and the other collects excess electrons.

A wire between the layers uses the movement to create electrical current.


Once the power plant has generated electricity, the current is sent through cables to substations, known as the transmission grid. Substations are a stopping point for electricity before it reaches homes and businesses.

Power substations deliver power, forming the distribution part of the electrical grid.

High voltage

Electricity arrives at the substation at a much higher voltage than is needed for businesses and houses. One of the substation’s primary jobs is to “step down” the voltage so it’s useful for consumers. Substation transformers perform this task.


The design of substations allows them to isolate and shut off sections to protect maintenance workers and consumers if necessary. Dangerous surges that may happen to weather or bad equipment can usually be quickly resolved at the substation.

Sharing the load

Just like a railway system adds more trains when it has more passengers to move, substations can transfer electricity to where it’s most needed. If a certain area has a higher demand, nearby substations can provide extra supply. 

Lightning protection

Substations have lightning arresters that are designed to guide lightning strikes into the ground without damaging any equipment. They also work when an extreme surge occurs. A lightning bolt to a transformer can cause citywide blackouts. 

Transmission networks

Managing the delivery of electricity to homes requires a very large scale network of power stations, substations, and transmission cables. As electricity can only travel in a closed circuit, all of these need to work together to ensure electricity arrives to homes. 

Most cities have several fallbacks to ensure that supply isn’t interrupted even if part of the circuit is broken.

Power plant

Electricity is generated at a power plant at a relatively low voltage. This generation occurs by the traditional burning of coal, capturing the power of running water or blowing wind, or the splitting of atoms (nuclear fission).

Step up

Special transformers located near the plant step up, or increase, the voltage. Power is transmitted at high voltages to increase efficiency. As electricity travels over long distances, energy losses occur due to resistance. 

Higher voltage results in lower current and lower losses. 


The electricity arrives at the substation at a very high voltage, and is then stepped down to a lower voltage. The types of equipment installed at a substation include transformers, switches, and voltage regulation devices.


The electricity is then sent along distribution lines to homes and businesses. Typically these lines are installed along the streets, overhead. Sometimes distribution cables are installed underground, although this method costs much more than overhead lines. 

Our electric future

The world is now electric. People depend on electricity in their everyday lives. However, burning fuel such as coal causes many issues with pollution, and supply is running low. 

Most countries in the world are now switching to renewable energy production such as wind, solar, and hydro to provide future electricity needs.

Electric cars

Cars now run on electricity, instead of burning gas for fuel. These cars can be charged using renewable sources. China has introduced revolutionary new changes to the automobile industry, insisting that all car manufacturers start producing electric cars from 2019. 

Renewable energy

China is becoming a world leader in renewable energy production. The largest electricity consumer in the world, the entire country aims to have at least half of its electrical needs met through renewable sources by 2030. 

New business opportunities

The diversifying of electricity generation sources and the targets set by countries like China means that many excellent business opportunities exist for people to work in the renewable energy field. 

This includes the development of devices that use electricity in a more efficient way.

Clean future

Ultimately, moving away from coal–generated electricity will benefit people around the world. These plants produce a lot of pollution, reducing air quality to those living nearby, and are major contributors to climate change. A finite resource, coal will run out one day. 

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
Explore more
Google apps