Wind — air, steel and land

Smokeless turbines, but not without concrete, copper, landscape or maintenance.

A giant machine for catching air

Converting wind into electricity: the basic mechanism

A wind turbine extracts kinetic energy from moving air by turning aerodynamically designed blades — with a profile similar to an aircraft wing — that transmit that rotation, through a shaft and a gearbox (or directly, in some designs), to an electrical generator. The energy available in wind grows with the cube of speed: doubling wind speed multiplies potentially extractable energy by eight, which explains why choosing the site — an area with consistently stronger winds — matters far more than any incremental improvement in the turbine's own design.

What has to be built before the first blade turns

A medium or large modern wind turbine gathers a considerable amount of steel for the tower, concrete for the foundation — which must anchor a structure dozens of meters tall subject to constant wind forces —, copper for the generator and wiring, and composite materials for the blades. Some generator designs, especially in large offshore installations, use permanent magnets that require rare-earth elements; other widely used designs do without them entirely. Generalizing that "wind needs rare earths" without specifying the generator type is a simplification that obscures more than it clarifies.

Two surfaces that are almost never told apart properly

A wind farm's land footprint has two very different scales that should not be confused. The direct footprint — each tower's foundation, access roads, the substation — takes up relatively little land. The total area of the farm — the space within which turbines must be spaced apart so as not to steal wind from each other — is much larger, but most of that surface can still be used for farming or grazing, unlike a mine, a well or a conventional thermal plant. Confusing the two surfaces produces spectacular but misleading comparisons of how much land wind energy "really occupies."

Decades of operation without burning anything, but not without maintenance

Over its working life — typically twenty to twenty-five years —, a wind turbine consumes no fuel, but does need periodic inspection and maintenance: blades and bearings suffer mechanical fatigue from constant rotation and variable wind loads, and may need repair or replacement before the whole installation reaches end of life. The impact on birds and bats, on visual landscape, and on noise perceived by nearby communities depends heavily on the specific site — it is not a fixed property of the technology, but something that varies by where and how each farm is installed.

The problem steel and copper do not have: the blade

At the end of its working life, most of a turbine — the steel tower, the concrete foundation, the generator's copper — is recycled through already-mature industrial channels, very similar to those for any other metal structure. The genuinely difficult component is the blade: made mainly of glass-fiber-reinforced composite material, designed to be light and extremely strong for two decades of operation, but not designed to be easily separated into its components at the end of that life. This recycling challenge — developed further in this leaf's data tab — is driving, in recent years, new reuse, shredding and chemical recycling routes for retired blades, precisely because the volume of turbines installed in past decades is now starting to reach end of life.

The site decides

In favor: low life-cycle emissions, little water consumption during operation, free fuel, and the possibility of coexisting with other land uses.

To watch: variability, new transmission lines, construction access, blade materials, biodiversity and local acceptance. Offshore, the resource can be better, but foundations, cables, ships and maintenance are more complex.

A prudent decision combines wind measurement, ecological assessment, local participation, curtailment or detection plans where needed, and a decommissioning contract agreed from the start.

The numbers, with their source

Two surfaces that are almost never told apart properly

A wind farm occupies far less land than it seems, if measured correctly. The direct footprint — foundation, access road, substation — has a median of only about 130 ha/TWh·yr, among the lowest of any source. But if the total area within which turbines must be spaced apart to avoid stealing each other's wind is counted, that figure can rise to 12,000 ha/TWh·yr. The difference matters because, apart from the tower base and the road itself, the rest of that total area can keep being used for farming or grazing — something that does not happen with a mine, a well or a thermal plant.

Source: NREL — Land use requirements of wind plants; comparison across sources in Our World in Data — Land use per energy source.

The problem steel recycling does not solve: the blade

Over 90% of a wind turbine's mass — steel tower, concrete foundation, copper generator — already has mature recycling channels. The problem is the blade: made of roughly 85% glass-fiber-reinforced polymer composite, a material designed to be light and strong for 20-25 years, not to be separated into its components at end of life. Since 1 January 2026, the European wind industry has applied a self-imposed ban on sending retired blades to landfill, which is accelerating four competing routes: reuse, mechanical shredding, cement co-processing, and chemical recycling or pyrolysis — none yet as cheap or as widespread as steel or copper recycling.

Source: Invrecovery — Wind Turbine Decommissioning and Blade Recycling: 2026 Playbook.

The comparative table

What this table is missing

The "rare earths" figure sometimes associated with wind only applies to generators with permanent magnets (more common in large offshore installations); many onshore turbines use generators without permanent magnets and do not depend on those materials. Generalizing "wind needs rare earths" without specifying the generator type is a simplification that confuses more than it clarifies.

Sources

• NREL distinguishes direct impact from total area in wind installations.
• The IEA analyzes the critical minerals required by clean technologies.
• The European Commission summarizes research on blade recycling and circularity.
• On the European landfill ban for blades starting 2026: Invrecovery — Wind Turbine Decommissioning and Blade Recycling Playbook.