What Are Wind Farms?

Wind farms are installations of multiple wind turbines arranged across a defined area to generate electricity at commercial scale. They function as power plants, delivering bulk energy to transmission or distribution networks, and are developed both onshore and offshore. The defining characteristic of a wind farm, as opposed to a single turbine, is that the collective output of many machines requires coordinated electrical infrastructure, shared control systems, and layout planning to maximize total energy production. The IEA wind energy overview notes that large onshore and offshore wind farms connected directly to high-voltage transmission networks now constitute the primary growth pathway for wind power globally.

Wind farms vary widely in scale: small community installations may comprise fewer than ten turbines rated at a few megawatts each, while large offshore projects may include hundreds of turbines with a combined capacity exceeding 1 GW. The economics of wind power favor larger plants because fixed costs for grid connection, permitting, and infrastructure are spread across more capacity.

Onshore and Offshore Layout

The physical arrangement of turbines within a wind farm is determined by a combination of land or seabed constraints, wind resource characteristics, access requirements, and wake interaction effects. Onshore wind farms must navigate property boundaries, terrain features, noise setback requirements, and visual impact considerations. Regular grid patterns are common where terrain is flat and wind is unidirectional, while irregular layouts follow land parcel geometry in areas with fragmented ownership. Offshore wind farms face fewer land-use constraints and benefit from stronger, more consistent winds; the absence of tall surface roughness produces lower turbulence and higher capacity factors, typically 36 to 53 percent offshore versus 28 to 39 percent onshore. Foundation type (monopile, jacket, or floating) is determined by water depth and seabed geology. An analysis of offshore wind farm layout optimization examines mathematical programming approaches for maximizing annual energy production subject to cable and foundation constraints.

Wake Effects and Optimization

When wind flows through a turbine rotor, the wake behind it carries reduced velocity and elevated turbulence. Downstream turbines operating in this wake produce less power and experience higher structural fatigue loads. In a densely packed wind farm, wake losses can reach 10 to 20 percent of total energy production and must be minimized through layout optimization. Computational fluid dynamics models and engineering wake models such as the Jensen top-hat model and the Gaussian wake model are used to estimate wake deficits at each turbine location and evaluate alternative turbine positions. Active wake management techniques, including wake steering through deliberate yaw misalignment of upstream turbines and axial induction control through partial derating, can redirect wakes and recover 3 to 10 percent of otherwise lost production. A review of offshore wind farm layout optimization and electrical system design methods covers both the aerodynamic modeling and the combined electrical-aerodynamic co-optimization approaches.

Electrical Collection Systems

The internal electrical infrastructure of a wind farm collects power from individual turbines and delivers it to a grid connection point or offshore substation. Medium-voltage collection cables, typically at 33 or 66 kV, connect turbines in radial or ring topologies, with radial strings being simpler and ring configurations providing redundancy. An offshore substation steps the collection voltage up to transmission level for export to shore via submarine cables, which may operate at high-voltage alternating current (HVAC) for shorter distances or high-voltage direct current (HVDC) for distances beyond approximately 80 kilometers. Transformer sizing, cable cross-sections, and protection relay coordination are all designed to minimize losses while maintaining required reliability levels.

Applications

Wind farms have applications across a range of electricity supply and planning contexts, including:

• Bulk electricity generation for national and regional transmission grids
• Offshore wind development for dense coastal population centers
• Community wind projects providing local energy generation
• Industrial self-supply for energy-intensive manufacturing operations
• Hybrid wind and storage projects providing firm renewable capacity