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How Electricity Reaches You: fun facts and quiz
The essentials in 7 ideas, with fun facts, an illustrated story and a quiz to see how much you know.
The essentials
Power Stations
Most electricity is made in power stations by spinning turbines connected to generators, turned by steam, wind or water. Solar panels are the big exception.
Key fact
Coal is still one of the biggest sources of electricity worldwide.
The Grid
The grid is the network of power lines linking power stations to homes. Supply has to match demand every second, or the system becomes unstable.
Key fact
Grid operators balance supply and demand around the clock.
High Voltage
Electricity travels long distances at very high voltage, sometimes over 400,000 volts, because less energy is lost that way. Transformers step it down before it reaches homes.
Key fact
Home sockets supply about 230 volts in Europe and 120 in the US.
Units & Bills
Electricity use is measured in kilowatt-hours (kWh). A 1,000-watt heater running for one hour uses 1 kWh.
Key fact
A 10-watt LED bulb can run for about 100 hours on 1 kWh.
Blackouts
If supply and demand fall badly out of balance, or key lines fail, parts of the grid can shut down. In 2003, a blackout left about 55 million people in North America without power.
Key fact
After a big blackout, grids restart carefully, area by area.
AC Wins
Grids use alternating current because transformers can easily change its voltage. That advantage settled the 1880s “war of the currents” in AC’s favour.
Key fact
Tesla and Westinghouse backed AC; Edison backed DC.
Smart Grids
Smart grids use sensors and data to balance power in real time, bringing in solar, wind and even electric car batteries. Grids have come a long way since Edison’s first power station in 1882.
Key fact
Smart meters send readings automatically.
Fun facts
Most fuel-burning power stations turn less than half of their fuel’s energy into electricity; the rest escapes as heat.
At peak times, grid operators can pay big factories to switch off for a while, instead of firing up another power station.
Birds can perch on power lines safely: no current flows through them unless they also touch something else.
One kilowatt-hour can run a typical laptop for around 20 hours.
In 2019, a single blackout left almost all of Argentina and Uruguay, nearly 50 million people, without power.
During the war of the currents, Edison’s side staged public electrocutions of animals to paint AC as deadly.
Edison’s Pearl Street Station in New York at first lit only about 400 lamps.
Story: The Night of 100,000 Lamps
The Night of 100,000 Lamps
1893. Chicago’s World’s Fair needs lighting. George Westinghouse, backing AC, underbids Edison’s company by more than half and wins the job.
On opening day, President Cleveland presses a golden key, and soon some 100,000 lamps light up the fair at night. Millions of visitors see AC work.
That year, Westinghouse also won the contract to harness Niagara Falls. In 1896, AC power from the falls reached Buffalo, over 40 km away.
True or false?
Tap your answer to see if you got it, and why.
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Question 1 of 10
Coal is still one of the biggest sources of electricity.
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True. Around the world, alongside gas.
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Question 2 of 10
Electricity supply must constantly be balanced with demand.
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True. Every second of every day.
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Question 3 of 10
Transformers reduce the voltage before it reaches homes.
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True. Step by step, down to socket level.
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Question 4 of 10
A 1,000-watt device running for an hour uses 1 kWh.
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True. That’s exactly what a kilowatt-hour is.
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Question 5 of 10
Grid failures can cause large blackouts.
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True. Failures can cascade across regions.
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Question 6 of 10
Transformers work with alternating current.
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True. That’s AC’s big advantage.
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Question 7 of 10
Smart meters can send readings automatically.
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True. No need for someone to read the meter.
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Question 8 of 10
Solar panels need spinning turbines.
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False. They turn light straight into electricity.
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Question 9 of 10
Electricity is stored in power lines for weeks.
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False. It’s used almost the instant it’s made.
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Question 10 of 10
Power lines carry the same voltage as your sockets.
Show the answer
False. They carry hundreds of times more.
Keep going in the app
KnowSoda learns what you know and brings back what you’re about to forget. How Electricity Reaches You has 6 more ideas at the Advanced and Expert levels.
Sources
- U.S. Energy Information Administration — Electricity explained
- National Grid (UK) — How the grid works
- IEA — Electricity 2024
- U.S.–Canada Power System Outage Task Force — Final report on the August 14, 2003 blackout
- IEEE — Pearl Street Station, 1882
- National Grid ESO — TV pickup and demand
- International Energy Agency — Electricity grids and transmission losses
