The energy journey
150 years of light.
150 years to go.
Everything in the modern world runs on energy. When it stops, hospitals, classrooms, data centres, kitchens, metros and cars stop with it. This page shows where we came from, where we stand, and where the work is still to be done.
Start the journeySkip to learningWhere we came from
From one lamp to a planet on a grid
People watched amber and lightning for thousands of years before anyone harnessed them. Then the first lamps lit single streets. Within one lifetime, wires carried power across countries. Here are the turning points.
The Nile's shocking fish
Documented Ancient Egyptian artists carved the electric catfish with care in Old Kingdom tomb reliefs, for example at Saqqara. People knew this fish gave a strong shock, long before anyone knew why. (Claims that they used it as medicine rest on weak evidence, so we leave them out.)
China: the lodestone attracts iron
Documented The Chinese text Guiguzi records that the lodestone attracts iron, one of the earliest written notes on magnetism.
Amber and the first spark
The Greek thinker Thales of Miletus is reported to have noticed that rubbed amber attracts feathers and dust. This is the oldest recorded observation of static electricity.
India: Kanada and the indivisible particle
Tradition, date debated The Vaisheshika school, attributed to the sage Kanada, taught that all matter is made of tiny, eternal, indivisible particles (later called paramanu) that differ in kind. The text reached its final form between about 200 BCE and the start of the common era; its core ideas may be older.
The Baghdad jars
Debated Clay jars found near Baghdad hold a copper cylinder and an iron rod sealed with bitumen. With an acid inside they give a small current, and some researchers think they were cells (for plating or healing). Others think they stored scrolls. Their purpose and exact age are still argued.
China: the south-pointing spoon
Debated Wang Chong's Lunheng has a passage often read as a lodestone spoon that settles to point south, the earliest form of the compass. Scholars debate whether it describes a real instrument.
India: the Agastya Samhita cell
Tradition, disputed A text attributed to the sage Agastya describes a clay pot with a copper plate, copper sulphate, damp sawdust and zinc. Accounts say verses were found in a manuscript in Ujjain in the 1890s, and that a 1990 reconstruction in Nagpur measured about 1.14 volts. These accounts are popular, not peer-reviewed, and the text's age is argued; it is not shown that the cell was ever used.
India: Aryabhata
Documented Aryabhata completes the Aryabhatiya, a compact work on arithmetic, algebra and astronomy that uses the Indian decimal place-value system. Engineering calculation grew on this kind of mathematics.
India: Brahmagupta and the number zero
Documented In the Brahmasphutasiddhanta, Brahmagupta sets out rules for calculating with zero and with negative numbers. The Bakhshali manuscript carries a zero symbol; its radiocarbon dates (about the 3rd to 4th century, or later leaves) are still argued by historians.
Baghdad: numbers travel west
Documented The scholar al-Khwarizmi writes on the Indian numerals and on calculation. His work carries the decimal system to the Arabic-speaking world and later to Europe. His name gives us the word algorithm.
China: the magnetic needle and true north
Documented Shen Kuo's Dream Pool Essays describe a needle magnetised with a lodestone and hung on a silk thread, and note that it points slightly off true south, the first record of magnetic declination. (Sources give 1086 or 1088.)
The word “electric” is born
William Gilbert, an English physician, publishes De Magnete, separates magnetism from static electricity and coins the Latin electricus, from the Greek word for amber, elektron.
Lightning is electricity
Benjamin Franklin's lightning experiments show that a thunderstorm is an electrical discharge, which leads to the lightning rod.
The first battery
Alessandro Volta builds the voltaic pile, the first device to give a steady, continuous current.
Motion makes electricity
Michael Faraday discovers electromagnetic induction. Every generator and transformer since is built on it.
The light bulb becomes practical
Thomas Edison and his team make a long-lasting incandescent lamp that ordinary people can use. Others built early lamps first; this one was built to be used and sold.
The first public power stations
Central stations in New York and London sell electricity to streets and homes. The power is direct current, which cannot travel far.
Alternating current: Nikola Tesla's motor and power system
Tesla's patents for polyphase AC motors and systems show that power can be sent far at high voltage and then stepped down for use. This is the idea behind every grid today.
175 km of three-phase power
A demonstration line in Germany carries AC power about 175 km. Long-distance transmission is proven.
Hydropower at Niagara
A large AC hydro plant sends power to a city 40 km away. Mills, trams and homes switch to the grid.
India: Jagadish Chandra Bose and invisible waves
Documented In Calcutta, Bose shows wireless signals at millimetre wavelengths passing through walls and ringing a bell 23 metres away. He later patents a crystal detector (US patent filed 1901, issued 1904). The IEEE recognises the work as a milestone.
Steam turbines, grids and rural wires
Turbines make power cheap. Countries build national networks and, from the 1930s, push wires to farms and villages.
India: Meghnad Saha and hot matter
Documented Saha derives the ionisation equation, which explains how heat strips electrons from atoms. It became a foundation of plasma physics, which fusion research relies on today.
India: C. V. Raman and light in matter
Documented Raman discovers that light changes colour slightly when it scatters in a material. He wins the Nobel Prize in Physics in 1930. The Raman effect is now widely used to study materials, including those in batteries and solar cells.
Nuclear power joins the grid; the silicon solar cell is born
The first grid-connected nuclear plant starts in the USSR. The same year, researchers make the first practical silicon solar cell.
India: Homi Bhabha and a nuclear programme
Documented Bhabha leads India's atomic energy effort. The Atomic Energy Establishment at Trombay is set up in 1954 (later renamed for him). India's first research reactor, Apsara, starts in 1956. The Tarapur Atomic Power Station begins supplying power in 1969.
Energy security and efficiency
Oil shocks teach the world that energy supply is also national and economic security. Efficiency standards begin.
The lithium-ion battery reaches the market
Rechargeable power fits in a pocket, and later in a car and a grid-scale store.
The Paris Agreement
Nearly every country agrees to cut emissions. Wind, solar and storage become the fastest-growing sources.
India and France launch the International Solar Alliance
Documented At the Paris climate meeting, India and France launch an alliance of sun-rich countries to cut the cost of solar power and share know-how. Its headquarters are in India.
Everything electrifies
Electric vehicles, heat pumps, data centres and artificial intelligence pull more and more of life onto the grid at the same time.
India passes half its power capacity from non-fossil sources
Documented India reached 50% non-fossil installed capacity in 2025, five years ahead of its 2030 pledge. By November 2025 non-fossil capacity was 262.74 GW, 51.5% of 509.64 GW, with solar at about 133 GW. Government figures; they change every month.
Each early entry is marked Documented, Debated or Tradition. This list is not complete: many peoples observed and used these forces, and we will add more as we check each source. If you know one, tell us.
India: a giver of knowledge
Many of the ideas under the grid began in India
Not only the West built the electric age. Mathematics, atomic thinking, wireless science and nuclear and solar power all carry India's hand. Here is what that means for the people who work in energy today.
| Idea | Who and when | Why it matters for energy | Status |
|---|---|---|---|
| Zero and decimal place value | Aryabhata (499 CE), Brahmagupta (628 CE); carried west by al-Khwarizmi | Every load calculation, protection setting and simulation uses this number system. | Documented (earliest zero symbol dates debated) |
| Indivisible particles of matter | Kanada and the Vaisheshika school, 6th to 2nd century BCE | An early, independent atomic idea. It is philosophy, not experiment. | Tradition, date debated |
| Fire, lightning and the cell | Vedic hymns; Agastya Samhita | India's oldest written reflections on energy; the cell claim is unproven. | Tradition, disputed |
| Millimetre waves and the crystal detector | J. C. Bose, 1895 to 1904 | Foundations of wireless, sensors and the semiconductor devices behind modern power electronics. | Documented |
| Ionisation in hot matter | Meghnad Saha, 1920 | Underpins plasma physics, central to fusion research. | Documented |
| Light scattering in materials | C. V. Raman, 1928 (Nobel 1930) | A standard tool for studying battery and solar materials. | Documented |
| A nuclear programme | Homi Bhabha; Trombay 1954, Apsara 1956, Tarapur 1969 | India built its own nuclear power capability and trained a generation of engineers. | Documented |
| Solar at scale | International Solar Alliance 2015; about 133 GW of solar by late 2025 | One of the world's largest and fastest renewable build-outs, and a huge skills demand. | Documented (government figures) |
Every civilisation added to this story: Egypt, Greece, China, the Arab world, India and many more. We show India's part clearly here because it is too often left out. The next chapter belongs to the 100 to 150 million people who learn and build.
Why alternating current won
Send it far, then step it down
Direct current flows one way and loses much of its energy over distance at low voltage. Alternating current swings back and forth, and a transformer can raise its voltage for the long journey and lower it again at the door. That single idea let one power station serve a whole region, and later a whole continent.
The lesson for every learner: the grid is a system. Generation, wires, protection, control and people all have to work together, every second.
Older roots
Fire, lightning and an old question about energy
Long before wires, people in India asked what energy is. Some of what follows is documented. Some is tradition. We label each, so you can trust what you read.
Tesla meets Swami Vivekananda, 1896
In February 1896 in New York, the inventor Nikola Tesla met Swami Vivekananda, who was bringing Vedanta to the West. Vivekananda wrote that Tesla believed he could show mathematically that force and matter are forms of potential energy, and that Tesla was drawn to the Vedic ideas of akasha (space, the all-pervading) and prana (vital energy). Vivekananda planned to return for the demonstration. No record of it survives.
Tesla's own words, 1907
In an essay dated 1907, Man's Greatest Achievement, Tesla uses the Sanskrit words Akasha and Prana for matter's primary substance and the force that shapes it. It was not published in his lifetime. Whether it came from Vivekananda is suggested by later writers, not proved.
Agni and Vidyut in the Vedas
The Rigveda honours Agni, fire, as the energy behind light and life. Later tradition describes fire in three realms: on earth, in the sun, and in the sky as vidyut, lightning. Calling vidyut “electricity” is a modern reading of an old word; the hymns speak of lightning and of illumination.
The Agastya Samhita “battery”
A text attributed to the sage Agastya describes a copper plate, copper sulphate, damp sawdust and zinc in a clay vessel. Accounts say a 1990 reconstruction in Nagpur measured about 1.14 volts, which is what that chemistry gives (the same family as the 19th-century Daniell cell). Those accounts are popular, not peer-reviewed. The age and authorship of the text are disputed, and whether it was ever used as a battery is not shown.
Why this matters: curiosity about energy is old and shared across peoples. We honour it without claiming more than the evidence shows.
Where we stand
The numbers behind the lights
Energy is finding a way into every sector of the 21st century, so this number will only grow. Electricity is the fastest-growing part of energy, and the people who build and run it are the limit on how fast we can go.
Who works in energy
Published count and our wider planning estimate, in millions of people.
The 76 million is the published figure for 2024 (5.4 million jobs added since 2019, growth of 2.2% in 2024). The 100 to 150 million range is our own planning estimate of the wider ecosystem of suppliers, builders, digital, finance and training. It is not an official statistic and still needs a full study.
What the energy workforce does
Our planning estimate by type of work (share of people).
This split is a planning assumption, not a published distribution. Published work shows that applied technical roles, such as electricians and line workers, are more than half of energy jobs.
Four areas of work, 38 kinds of job
| Area of work | Kinds of work | People (planning estimate) |
|---|---|---|
| Clean technology and efficiency | 10: solar, storage, EV charging, green buildings, lighting, carbon, efficiency | about 24 million |
| Power and automation | 10: transmission, substations, controls, digital substations, grid software, smart meters, local generation | about 31 million |
| Smart city assets | 8: smart buildings, communities, infrastructure, water, turbines | about 18 million |
| Services | 10: cabling, power projects, low-voltage work, grid automation, renewable and generation services, telecoms, cyber | about 32 million |
| Total | 38 | about 105 million (base case) |
A first-pass model on a base of 105 million people. The higher figures in the range scale the same way. Not measured national statistics.
Power for digital life
Electricity used by the world's data centres, TWh a year (published estimate and projection).
Roughly doubling in six years, driven by artificial intelligence. Every model, every video and every search sits on a power station.
Power for movement
Electric cars sold worldwide in 2024, millions, and share of all new cars.
Two-wheelers, three-wheelers, buses and trucks are following. Charging is now part of the grid.
of the world's electricity now comes from renewable sources
fall in solar power cost since 2010
of people worldwide have electricity at home. Hundreds of millions still do not.
Figures are rounded from published international statistics (see sources) and change every year.
Measured, dated, kept
The trend, with its history
We measure the energy workforce on a schedule and keep every reading. Nothing is overwritten, so our learning builds into a record anyone can check.
Loading the history…
Every reading we have kept
| Date | Refresh | Measure | Value | Kind | Source |
|---|---|---|---|---|---|
| Loading… | |||||
Kind: published = from a published statistic; estimate = our own planning estimate; derived = worked out from published figures. Each reading is chained to the one before it, so a change to history would show.
Energy is a vector into every sector
Switch the power off. See what stops.
Energy is not one industry among many. It is the road every other industry travels on. Press the button and watch.
Data centres
Servers and cooling need constant power. The internet, banking and cloud depend on it.
Superintelligence and AI
Training and running AI takes huge amounts of electricity. Intelligence needs power.
Healthcare
Operating theatres, scanners, ventilators and cold storage for vaccines.
Education
Classrooms, laptops, labs and online learning reach children because the lights are on.
Food and beverage
Farms, cold chains, processing plants, kitchens and shops.
Homes
Light, cooling, heating, water pumps, cooking and phones.
Metros and trains
Traction power, signals and stations move millions a day.
Cars, buses and two-wheelers
More of the world's vehicles are becoming electric, and charging is the new fuel station.
Water
Pumping, cleaning and desalination use power at every step.
Factories and mines
Every product starts with machines that run on power.
So energy skills are not only for the people who work for power companies. A nurse, a farmer, a teacher, a shop owner and a builder all do better when they understand how to work with energy.
In remembrance
Once upon a time, they imagined it
Thales watched amber. Gilbert named it. Franklin read the sky. Volta stored it. Faraday made it move. Edison lit a room, Tesla sent it across a country. Before them, seers and sages asked what energy is.
None of them saw the data centre, the metro or the electric car. They imagined a world that would be lit, and they gave their lives to it. We live inside what they dreamed.
What we build today will light someone's classroom a hundred years from now. We owe them the same care that those before us gave to us.
“Man is here for the sake of other men.”
“… I must exert myself in order to give in the same measure as I have received and am still receiving.”
Albert Einstein, “The World As I See It” (essay of 1930, in the 1934 collection; wording differs a little between English translations).
Our call to every professional: bring respect, responsibility and determination. Respect for the people and the generations behind the switch. Responsibility for safety, quality and honest work. Determination to finish what we start. Einstein asks us to give as we have received. We ask each other to try to give more.
What we learned, what we did, what is left
Three questions for any journey
What we learned
- Power travels furthest as high-voltage AC; systems beat single machines.
- Safety is built in, never added later. Every rule was written after an accident.
- Reliable energy lifts health, learning and income. Access changes lives.
- Cheap energy has costs we must count, including air, climate and security.
- People are the limit. Machines can be built faster than skilled workers can be trained.
The work we have done
- Built grids that reach about 9 in 10 people.
- Made solar, wind and batteries cheap enough to compete everywhere.
- Turned electricity into the carrier for transport, heat and computing.
- Written standards so equipment from different makers works together safely.
- Trained generations of electricians, technicians and engineers, one apprenticeship at a time.
The work yet to come
- Bring power to the people still without it.
- Rebuild and strengthen grids for much higher demand.
- Store energy for days, not only hours.
- Protect energy systems from cyber attacks.
- Train and certify tens of millions more skilled people, in every country.
The next 150 years
Three horizons. One direction.
Nobody can predict 150 years. These are pathways to plan for and to argue about, not forecasts. What does not change: more of life runs on electricity, and it needs people who know how.
Electrify and clean up
Cars, buses, heating and industry move to electricity. Solar, wind and storage lead new supply. Grids are upgraded and made digital. Demand from data centres and AI keeps rising.
Work needed: installers, grid engineers, protection and control specialists, battery and charging teams, cybersecurity.
A flexible, stored, shared grid
Energy is generated close to where it is used and shared between neighbours, cities and countries. Long-duration storage, clean hydrogen and next-generation nuclear take a larger part. Machines help operate the grid.
Work needed: system operators, storage and hydrogen engineers, data and AI specialists, recyclers, regulators.
Abundant, clean, invisible
If new sources such as fusion, space-based power and far better storage mature, energy could become plentiful and clean enough that people think about it as little as they do about tap water today. Maintenance of this system would still need skilled hands.
And if humanity grows into an interstellar species, the demand for people who understand energy grows with it: every ship, station and settlement will run on it.
Work needed: skills we cannot name yet, built on the habit of learning.
| Era | Main carrier | Typical skill in demand |
|---|---|---|
| 1880 to 1950 | Steam, water, coal; first grids | Electrician, lineman, plant engineer |
| 1950 to 2000 | Large plants, oil, gas, nuclear; national grids | Power engineer, control engineer, technician |
| 2000 to 2050 | Solar, wind, batteries; electric transport; digital grids | Installer, grid analyst, software and cyber engineer |
| 2050 and beyond | Storage, shared grids, new sources | System thinker who can learn the next tool |
Learn it to Earn it
Courses we propose to build on this journey
A draft path from first light to a certified career, for the 76 million and for every person who works near energy. Each course has short lessons, practice and a skill certificate.
Energy for Everyone
How electricity is made, moved and used, and how it touches your sector.
Working Safely with Electricity
Hazards, isolation, protective equipment and first response.
Wiring, Panels and Protection
Low-voltage systems, switchgear, protection devices and testing.
Grids, Substations and Control
Transmission, distribution, SCADA and digital substations.
Solar, Storage and Clean Power
Design, install and maintain solar and battery systems.
EV Charging and Electric Mobility
Chargers, load management, safety and fleet planning.
Power for Data Centres and AI
Resilient supply, cooling, backup and energy efficiency.
Energy Efficiency and Management
Measure, audit, save and report energy in buildings and plants.
Cybersecurity for Energy Systems
Protect control systems and critical infrastructure.
Energy for Health, Food, Water and Education
One short course for each sector: what stops without power and how to plan for it.
These are proposals for review. Fees, dates and enrolment will be announced when each course is ready.
Explore learningSources and notes
- Energy employment (76 million in 2024, 5.4 million added since 2019, 2.2% growth): international energy agency, World Energy Employment 2025.
- Data centre electricity (about 415 TWh in 2024, about 945 TWh by 2030): international energy agency, Energy and AI report, 2025.
- Electric car sales (over 17 million in 2024, over 20% of new cars): international energy agency, Global EV Outlook 2025.
- Share of renewable electricity (about 30% in 2023): independent global electricity review by the Ember think tank, 2024.
- Solar cost fall (about 90% since 2010): international renewable energy agency, Renewable Power Generation Costs, 2023.
- Access to electricity (about 91% of people in 2022): World Bank, Tracking SDG7 report, 2024.
- Egypt: Old Kingdom tomb reliefs showing the electric catfish (for example at Saqqara); museum and Egyptological summaries. China: Guiguzi (4th century BCE); Wang Chong, Lunheng (1st century CE, interpretation debated); Shen Kuo, Dream Pool Essays (1086–1088), summarised in histories of the compass.
- Baghdad jars: found 1936 near Baghdad and proposed as cells by W. König; purpose and date debated (for example P. T. Keyser, 1993, Journal of Near Eastern Studies, on healing use).
- Agastya Samhita cell: reported by popular sources (the Sanskrit Magazine and others) from the work of R. K. Vajhe in the 1890s and a 1990 Nagpur reconstruction. Not peer-reviewed; we label it Tradition, disputed.
- J. C. Bose: IEEE Milestone “First Millimeter-wave Communication Experiments by J. C. Bose, 1894-96” (ETHW); US patent 755,840 (Computer History Museum, semiconductor timeline).
- India: Vaisheshika Sutra and Kanada (dating from critical-edition studies, 200 BCE to start of common era, author earlier; encyclopaedic summaries). Aryabhata, Aryabhatiya (499 CE); Brahmagupta, Brahmasphutasiddhanta (628 CE); Bakhshali manuscript radiocarbon results (Bodleian Libraries, University of Oxford, 2017) and the historians' response (History of Science in South Asia, 2017). Al-Khwarizmi on the Indian numerals (about 825 CE).
- Saha ionisation equation (1920) and C. V. Raman, Raman effect (1928; Nobel Prize in Physics 1930): standard histories of physics. Bhabha, Trombay (1954), Apsara (1956) and Tarapur (1969): Department of Atomic Energy and Bhabha Atomic Research Centre histories.
- International Solar Alliance, launched by India and France at the Paris climate meeting, 2015. India non-fossil capacity (262.74 GW, 51.5% of 509.64 GW, November 2025) and solar (about 132.85 GW): Ministry of New and Renewable Energy and Press Information Bureau releases, December 2025.
- Early history: Thales and amber (reported by later Greek writers); Gilbert, De Magnete, 1600; Franklin, 1752; Volta, 1800; Faraday, 1831. See the Britannica summary of electricity and the US Energy Information Administration electricity timeline.
- Tesla and Vivekananda: Vivekananda's letter of February 1896 to a friend (published in Letters of Swami Vivekananda, Advaita Ashrama). Tesla, Man's Greatest Achievement, dated 1907, first printed in 1930. The influence link is an interpretation by later writers.
- Agni and vidyut in the Vedas and the Agastya Samhita: traditional texts; dating and authorship are debated by scholars. We describe them as tradition, not as proven engineering.
- Einstein: “The World As I See It”, 1930 essay (published in Forum and Century, 1930; Mein Weltbild, 1934). Translations vary.
- History: Edison's practical lamp 1879; first public power stations 1882; Tesla's polyphase AC patents 1888; Lauffen to Frankfurt 175 km demonstration 1891; Niagara AC power plant 1895; Obninsk nuclear plant 1954; commercial lithium-ion cell 1991; Paris Agreement 2015. All widely documented in engineering histories.
- The 100 to 150 million workforce range, the 125 million middle figure, the split by type of work and the 38-kinds-of-work table are our own planning estimates, built from the published 76 million and a classification of the wider ecosystem. They are not official statistics and will be refined by a full study.
- The next-150-years horizons are possible pathways, not forecasts.