Renewable Energy

How wind
turbines generate
electricity.

From spinning blades to the national grid. One turbine can power 1,500 homes. A large offshore farm can power a million.

Faraday's Law Nacelle Grid Connection Offshore Wind

01 — Inside the Nacelle

The box at the top of the tower contains an entire power station.

The nacelle sits atop the tower and houses every mechanical and electrical component that converts wind into electricity. Click any component to learn what it does.

Click any labelled component to see its function
Select a component
Click on any numbered component in the diagram above to see a detailed explanation of its role in generating electricity.

02 — Blade Diameter

One rotor. Wider than a Boeing 747.

Modern offshore turbine blades are almost incomprehensibly large. A single blade is longer than an Airbus A380 is wide. The rotor sweeps an area bigger than two football pitches.

Rotor diameter vs real-world objects — drawn to scale
Vestas V236 — World's Largest (2023)
236 m rotor diameter · 115.5 m per blade
Swept area: 43,000 m² (6 football pitches)
Rated power: 15 MW
Why so big?

Power extracted from wind scales with the square of rotor diameter — double the diameter, quadruple the power. Longer blades also sweep slower-moving air at low hub heights and capture more energy at low wind speeds.

Blades are hollow carbon fibre and fibreglass — lighter than they look, but each one still weighs ~40 tonnes.

03 — Tower Height

Taller than most skyscrapers.

Wind turbine towers need height to reach faster, more consistent winds. Modern offshore towers place the hub over 150 m above sea level — two-thirds the height of the Eiffel Tower.

Height comparison — drawn to scale
Why height matters
Wind speed increases with altitude (wind shear). At 150 m, wind is typically 20–25% faster than at 80 m. Since power scales with the cube of wind speed, a 20% speed increase means 73% more power. Every extra metre of height is worth more energy.
Tower construction

Onshore towers are typically steel, bolted together in sections. Offshore, monopile foundations are driven up to 40 m into the seabed.

The total tip height of a modern offshore turbine — tower + hub + blade — can reach 280–300 m, making them among the tallest structures ever built.

04 — Grid Connection

From turbine to your light switch.

Electricity generated at each turbine travels through a chain of cables and transformers before reaching the national grid. Offshore wind farms use either AC or HVDC export cables depending on distance.

AC export — used for distances under ~80 km from shore
AC Export (≤ 80 km)

Turbines generate at 690 V AC. Array cables step up to 33–66 kV. The offshore substation transforms to 132–220 kV for the export cable. At the onshore substation, voltage is stepped up again to 275–400 kV for the national grid.

HVDC Export (> 80 km)

AC cables lose too much power over long distances. HVDC (High Voltage Direct Current) converts AC to DC at the offshore platform, transmits at up to ±320 kV DC, then converts back to AC onshore. Losses are only ~3% per 1,000 km.

05 — Pitch & Yaw Control

Two rotations that tune every watt.

Pitch rotates each blade around its own axis to control angle of attack. Yaw rotates the entire nacelle to track the wind. Together they maximise output and protect the drivetrain in all conditions.

BLADE PITCH
Pitch Angle
Optimal pitch — blades biting wind at full efficiency
NACELLE YAW
Yaw Offset
Nacelle aligned with wind — maximum rotor capture
How Pitch Works

Each blade has a large bearing at its root that lets it rotate along its own span. Below rated wind speed, blades are pitched at ~5° to maximise lift and rotor torque. Above rated (≈14 m/s), the controller feathers blades progressively toward 90° — shedding aerodynamic force and holding the generator at exactly rated power. At 25 m/s (cut-out), blades go fully feathered and the turbine stops.

How Yaw Works

A ring of electric motors drives the nacelle on a slewing bearing so the rotor always faces into the wind. Power lost to yaw misalignment scales with cos³(θ) — a 10° offset loses only ~1.5%, but 30° loses 35%. Modern offshore turbines use LIDAR to scan wind direction up to 200 m upstream, adjusting yaw before a wind shift even reaches the rotor.

06 — Power Transfer

Wind speed, pitch, yaw — all three control output.

Adjust the controls below and watch how each variable affects the turbine's power output in real time. Power scales with the cube of wind speed — small changes in wind make a huge difference.

Wind Speed 10 m/s
Pitch Angle
Yaw Offset
5.2 MW Power output
35% Of rated capacity
1,733 Homes powered
NORMAL OPERATION

Turbine is operating within normal wind speed range. Pitch is optimised for maximum energy capture. Nacelle is aligned with the wind.

Live turbine animation — power flow visualised
Power curve — output vs wind speed (P ∝ v³ between cut-in and rated speed)

07 — Global Manufacturers

The companies building the world's wind fleet.

A handful of OEMs (Original Equipment Manufacturers) design, build, and service the turbines generating most of the world's wind energy. The market is split between European pioneers who dominated for decades and Chinese manufacturers who have rapidly scaled to compete on size and volume.

● EUROPE ● NORTH AMERICA ● CHINA ● INDIA
Vestas
DENMARK

V236-15 MW — the world's most powerful commercially available offshore turbine. 236 m rotor, 15 MW rated power, one turbine powers ~16,000 homes.

Onshore Offshore ≤ 15 MW
Siemens Gamesa
SPAIN / DE

SG 14-236 DD — 14 MW direct-drive offshore turbine. 236 m rotor, no gearbox. Dominant in European offshore; owned by Siemens Energy.

Onshore Offshore ≤ 14 MW
GE Vernova
USA

Haliade-X 14 MW — 220 m rotor offshore. Also builds the Cypress onshore platform (5.3 MW). Spun out of GE as an independent company in 2024.

Onshore Offshore ≤ 14 MW
Enercon
GERMANY

E-175 EP5 (5.56 MW) — pioneer of direct-drive gearless turbines. No gearbox means fewer moving parts and lower maintenance. Focuses exclusively on onshore markets.

Onshore only ≤ 5.56 MW
Nordex
GERMANY

N175/6.X (6 MW) — pure onshore specialist. Strong in Germany, Scandinavia, and Latin America. Known for high-wind and low-wind site variants.

Onshore only ≤ 6 MW
Goldwind
CHINA

GWH252-16 MW — 252 m rotor offshore. China's largest wind OEM by cumulative installed base. Uses permanent magnet direct-drive (PMDD) across its range.

Onshore Offshore ≤ 16 MW
Ming Yang
CHINA

MySE 16.0-242 — 242 m rotor, 16 MW. The fastest-growing offshore OEM in China. Has announced 18–20 MW prototypes targeting the world power record.

Onshore Offshore ≤ 16 MW
CSSC Haizhuang
CHINA

H260-18 MW — 260 m rotor, one of the most powerful turbines ever built. Part of China State Shipbuilding Corporation. Applies naval engineering to offshore turbine manufacturing.

Offshore ≤ 18 MW
Dongfang Electric
CHINA

DFWT-18000-260 — 18 MW, 260 m rotor. Part of state-owned Dongfang Electric Corporation, a major supplier of power generation equipment across thermal, hydro, and wind.

Onshore Offshore ≤ 18 MW
Envision
CHINA

EN-236/12 MW — strong in Chinese onshore and expanding offshore. Pairs turbines with its own AIOS smart energy management platform for grid integration.

Onshore Offshore ≤ 12 MW
SANY Renewable
CHINA

SE13530 (13.5 MW offshore) — subsidiary of SANY Group (the world's third-largest construction equipment maker). Leverages heavy-machinery manufacturing expertise.

Onshore Offshore ≤ 13.5 MW
Suzlon
INDIA

S144 Hybrid Lattice (3 MW) — India's dominant OEM with the largest installed base on the subcontinent. Uses hybrid lattice towers to reach taller hub heights where land speeds are stronger.

Onshore only ≤ 3 MW
Inox Wind
INDIA

DF116-120 (3 MW) — India's second-largest OEM, focused on 3 MW onshore platforms optimised for India's varied wind regimes. Rapidly scaling capacity to meet India's 500 GW renewable target by 2030.

Onshore only ≤ 3 MW
The Turbine Arms Race

Rated power has doubled roughly every decade — from 1.5 MW in the 1990s to 18+ MW today. The race is now almost entirely about offshore turbines: larger rotors sweep more area (P ∝ r²), taller towers reach faster and more consistent winds, and fewer turbines mean lower installation and cable costs per MW. Chinese OEMs now hold the records for rated power and rotor diameter, while European OEMs still lead on offshore commercial deployment volume and operational track record. Global installed wind capacity passed 1 terawatt in 2023.