NABCEP Small Wind Installer

Question 1

What is the generally recommended minimum average annual wind speed for a cost-effective small wind turbine installation?

Accepted Answer

10 mph (4.5 m/s)

Answer

6 mph (2.7 m/s)

Answer

15 mph (6.7 m/s)

Answer

20 mph (8.9 m/s)

Question 2

Wind power is proportional to the cube of wind speed. If wind speed doubles, how does the available power in the wind change?

Accepted Answer

It increases by a factor of eight

Answer

It doubles

Answer

It quadruples

Answer

It increases by a factor of six

Question 3

Which instrument is the primary tool used to measure wind speed during a small wind site assessment?

Accepted Answer

Anemometer

Answer

Barometer

Answer

Hygrometer

Answer

Pyranometer

Question 4

Per the widely accepted '30-foot rule,' how much taller should a small wind turbine hub be above any obstruction within 500 feet of the installation?

Accepted Answer

30 feet

Answer

10 feet

Answer

20 feet

Answer

50 feet

Question 5

What is the Rayleigh distribution used for in small wind site assessment?

Accepted Answer

Modeling the statistical frequency of wind speeds at a site

Answer

Calculating tower foundation loads

Answer

Estimating turbine oil change intervals

Answer

Determining electrical conductor sizing

Question 6

What is a wind shadow (turbulence zone) that forms downwind of an obstruction such as a building or tree line?

Accepted Answer

A zone of reduced and turbulent airflow extending 10–20 times the height of the obstruction downwind

Answer

A region of accelerated wind speed behind the obstacle

Answer

An area where ice accumulates on turbine blades

Answer

A zone where wind changes direction by more than 45 degrees

Question 7

Which of the following best describes a 'furling' mechanism on a small horizontal-axis wind turbine?

Accepted Answer

A passive system that turns the rotor out of the wind to prevent overspeed in high winds

Answer

A blade pitch system that maximizes power at all wind speeds

Answer

A mechanical disc brake applied during maintenance shutdowns

Answer

An electronic inverter that converts variable-frequency AC to grid-compatible AC