Wind Farm Capacity Calculator

Work out wind farm capacity instantly with clear inputs, formula shown and shareable results.

About Wind Farm Capacity Calculator

Installed capacity is simply turbine rating times count, but wake losses of 5-15% mean the array delivers less than the sum of its parts. Layouts typically space turbines 5-9 rotor diameters apart downwind and 3-5 crosswind, which sets the site area and a power density of 3-6 MW per square kilometre.

Formulas

Wind farm capacity

Installed capacity = turbine rating x number of turbines; effective = installed x (1 - wake loss)

Site area

Area = 7D x 4D x turbines, with D the rotor diameter

Worked example

With the default values below, Wind Farm Capacity Calculator returns Installed Capacity of 105.000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Turbine Ratingminimum 0 MW: 4.2 MW
Number Of Turbinesminimum 1: 25
Rotor Diameterminimum 0.01 m: 145 m
Wake And Array Lossaccepts 0–40 %: 8 %

Results

Installed Capacity: 105.000
Effective Capacity After Wake Loss: 96.600
Indicative Site Area: 14.718
Power Density: 0.0713

Step by step

1Values used
2Wind farm capacity
3Site area
4Installed Capacity= 105.000
5Effective Capacity After Wake Loss= 96.600
6Indicative Site Area= 14.718
7Power Density= 0.0713

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why are wake losses unavoidable?

A turbine extracts energy from the wind and leaves a slower, more turbulent wake. Downwind turbines see reduced wind speed, and because power varies with the cube of speed, even a small deficit costs output.

Does the land become unusable?

No. Turbine foundations and access roads occupy 1-3% of the site area; the rest remains available for farming or grazing, which is why wind leases coexist with agriculture.