Site selection
Place the turbine and describe the wind there. Air density comes from the ground elevation through the ISA standard atmosphere; every later step reads these values.
Map
Click the map or drag the pin to move the site; the elevation is looked up for the new point. The Global Wind Atlas link opens its map zoomed on these coordinates; click the point there if its wind statistics are not listed, then type them in here.
Coordinates
Wind resource
Design parameters
The rating, the rotor's blade count and design tip-speed ratio, the sizing guess for Cp, and the three blade sections. The blade shape itself is chosen in step 4.
Power & rotor
Reference-study recommendations
Fixed recommendations from the reference study's design rules (only the blade-count note depends on the rating). Values that differ from yours are marked.
Airfoil sections
Design angle of attack — best L/D
| Section | Airfoil | α* (°) | CL | CD | L/D |
|---|
Turbine sizing
The rotor radius that makes the rated power at the hub-height wind, with the hub at twice the radius — Roger's A3 method, iterated to convergence. It is an open-loop estimate: step 5 checks it against the finished blade.
Solver
Iteration table
| Iter | R (m) | A (m²) | H (m) | Vhub (m/s) | Rnew (m) |
|---|
Governing equations
V(h) = Vref · (h / href)1/7
H = 2 · R (siting rule)
Ω = λ · Vhub / R · rpm = 60 Ω / 2π
A3 sizes with Cp = Cp,init and no drivetrain efficiency (η = 1): the electrical rating is reached only at the derived rated wind speed of step 5, above this sizing wind V(H).
Blade design
Chord and twist along the span, fixed at manufacture. Choose the laws here; the performance step then solves this blade with blade-element momentum theory.
Blade laws
Planform — top view
Cross-sections
Twist distribution
Blade elements
| r/R | r (m) | Chord (m) | Twist (°) | φopt (°) | Section |
|---|
Performance analysis
Blade-element momentum theory (Ning's bracketed residual) with Prandtl tip and hub loss, the Glauert–Buhl high-induction correction and the bounded Du–Selig 3-D stall delay; a controller that tracks the blade's own λopt and pitches to feather above the derived rated speed.
Operating envelope
Power curve electrical, P vs V
Rotor efficiency Cp vs λ, twist frozen, Ω varied
3-D vs 2-D polars same controller
Spanwise loading
Operating schedule
Economic analysis
Annual energy from the step-5 power curve over the Weibull distribution at hub height, with the sheet's part-load drivetrain efficiency and losses; costs from the NREL/TP-500-40566 scaling model as in Roger's LWST COE sheet (2002 $), with one inflation factor on every term.
Financial parameters
Wind and energy at hub height
Cost of energy Aer vs Roger's A4
NREL component costs
| Component | 2002 ($k) | Adjusted ($k) |
|---|
Environmental assessment
A screening noise estimate (a source level from tip speed and diameter unless a manufacturer's value is given, ISO 9613-2 propagation), shadow-flicker screening, sourced avian context and permit screening for the site.
Receptor
Noise against distance level ground
Annual U.S. bird deaths by cause A5 Table 3, log scale
Current estimates as Roger's A5 (p.12, Table 3) gives them; bars at the middle of each range: cats 1.3–4 billion (Loss et al. 2013; ABC); windows 100 million–1 billion; power lines 130–174 million; automobiles 60–80 million; pesticides 70 million; lit communication towers about 7 million (ABC); wind turbines 0.7–1 million (ABC). A5: turbines cause less than 0.1% of unnatural U.S. bird deaths.
Avian & wildlife — species of concern
Regulatory checklist
Design report
Regenerated from a fresh run of every step each time you open it, stamped with the date and a hash of the inputs. It prints on a light page.