NABCEP Wind Energy Site Assessment Flashcards

Which IEC standard governs the design requirements and safety of wind turbines used in small wind energy system applications?

Answer: IEC 61400-2 (Design requirements for small wind turbines)

IEC 61400-2 specifies structural, aerodynamic, and electrical safety design requirements specifically for small wind turbines with rotor swept areas up to 200 m², the category relevant to distributed wind installations.

What is the purpose of a wind turbine's furling mechanism in small horizontal-axis turbines?

Answer: To passively turn the rotor out of the wind in high-speed conditions to prevent overspeed and damage

Furling uses a hinged tail mechanism to turn the rotor sideways out of high winds, passively protecting the turbine from overspeed without electronic controls.

What tower height consideration is most important for maximizing wind energy production at a site with significant obstructions such as trees or buildings?

Answer: The tower should place the rotor hub at least 30 feet above any obstruction within 500 feet to avoid turbulence

Industry guidelines recommend hub height at least 30 feet above obstructions within 500 feet; closer obstructions create turbulence that reduces energy output and increases turbine fatigue loads.

What is the annual energy production (AEP) calculation used for in wind project feasibility?

Answer: To estimate the total kWh the turbine will produce annually, used to evaluate economic viability and financial returns

AEP combines the turbine's power curve with the site's wind speed distribution to estimate annual energy output in kWh, which is used to calculate revenue, payback, and return on investment.

What does 'interconnection agreement' refer to in a small wind turbine installation?

Answer: A formal agreement with the utility authorizing the turbine to connect to and export power onto the electric grid

A utility interconnection agreement is a legal contract governing the technical, safety, and metering requirements for connecting a distributed generation system to the utility's distribution grid.

Which federal agency must be notified for wind turbine installations that exceed certain heights near airports or in navigable airspace?

Answer: FAA (Federal Aviation Administration)

The FAA requires notification (Form 7460-1) for structures that may affect navigable airspace, including wind turbines above certain heights, and may require aviation lighting on tall towers.