Why Do Wind Turbines Stop in Strong Wind?
A gale carries more energy than a turbine can safely take. Why output flattens at rated speed, how blades shed power, and what cut-out really protects.
Updated 8 October 20267 min read
Topic
Wind & Hydropower
Wind and water turbines both pull energy from a moving fluid. A few equations explain turbine sizing, siting, head and flow, and why wind speed matters.
Wind and hydro look like different industries, but a rotor does not care which fluid is pushing it. In the wind, power rises with the cube of wind speed; in a stream, it rises with the product of head and flow. Those two relationships explain most of the design decisions covered here.
In this section you will find why no open rotor can capture more than 59.3% of the wind's power — the Betz limit — why large turbines settle on three blades, and why they deliberately shed power or shut down when the wind becomes too strong. Offshore, the question changes to how electricity crosses the seabed to shore, and why long export cables switch from alternating to direct current.
On the hydro side, the guides cover how a micro-hydro site is assessed from head and flow, why gross head is never net head, and how Pelton, Turgo and cross-flow turbines suit different combinations of the two. The approach throughout is engineering first: equations, worked examples in metric and imperial units, and no product or price talk.
Why Do Wind Turbines Have Three Blades?
Three blades is the fewest that loads a rotor evenly while capturing nearly all the available energy. Why two shakes, why four barely helps, and the cost.
Updated 8 October 20267 min read
What Is the Betz Limit?
No open-flow rotor can capture more than 59.3% of the wind's power. The derivation in full, what the Betz limit does not say, and where it does not apply.
Updated 8 October 20267 min read
Pelton vs Turgo vs Cross-Flow Turbines
Three impulse turbines, three ways of catching a jet. How bucket shape sets the head and flow each suits, and why part-flow efficiency decides real sites.
Updated 8 October 20267 min read
How Offshore Wind Farms Send Electricity to Shore (HVAC vs HVDC)
A submarine cable behaves nothing like an overhead line. Why AC export runs out of room with distance, what HVDC buys, and where the crossover point sits.
Updated 8 October 20267 min read
How Micro-Hydro Power Works: Head, Flow and Power
Two measurements decide a micro-hydro site. How head and flow become power, why gross head is never net head, and what a flow duration curve really tells you.
Updated 8 October 20267 min read