Environmental Technology Systems 1

What is the minimum head required for a suitable water source for micro-hydro-electric generation?

• 10 m

• 1 m

• 15 m

• 5 m

What is the main advantage of micro-hydro-electric systems?

• Noise and vibration

• High initial cost

• Variable performance

• Reliable energy source

What is the purpose of a forebay in a micro-hydro system?

• To return water to the main stream

• To divert water from the main stream

• To house the turbine and generator

• To hold a reservoir of water

What is the main disadvantage of micro-wind turbines?

• Variable output

• Low efficiency

• High initial cost

• No carbon dioxide emissions

What is the purpose of a system controller in an off-grid micro-wind system?

• To charge batteries

• To convert d.c. to a.c.

• To store electricity for later use

• To connect to the grid supply

What is the minimum wind speed required for a wind turbine to generate electricity?

• 2 m/s

• 10 m/s

• 5 m/s

• 8 m/s

What is the main purpose of the tailrace in a micro-hydro system?

• To house the turbine and generator

• To return water to the main stream

• To divert water from the main stream

• To hold a reservoir of water

What is the main purpose of the gearbox in a wind turbine?

• To turn the turbine to face the wind

• To drive the generator

• To convert d.c. to a.c.

• To store electricity for later use

What is the main purpose of the nacelle in a wind turbine?

• To convert d.c. to a.c.

• To store electricity for later use

• To drive the generator

• To house the gearbox and generator

What is the main purpose of the PV system in a building?

• To reduce electricity imported

• To reduce energy performance

• To increase energy performance

• To increase electricity imported