Deck 7: Solar Electricity

Question 1

A(n) _____ is one in which some built-in asymmetry draws the excited electrons away and delivers them to an external circuit before they can relax.

A) electromagnetic device
B) nuclear power plant
C) photovoltaic device
D) conventional power plant

Answer 1

C

Question 2

​A photovoltaic array can interact with a utility grid without an inverter.

Answer 2

False

Question 3

​Photovoltaics is the ______ .

A) indirect conversion of sunlight into electricity
B) direct conversion of sunlight into electricity
C) focusing of the sun's energy to boil water, create steam, and drive turbines
D) production of electricity in a similar fashion as conventional power plants

Answer 3

B

Question 4

_____ dramatically alters the electrical behavior of silicon in the production of electricity.

A) Sand
B) Doping
C) Sunlight
D) Pressure

Question 5

​Most of the solar energy that strikes a silicon cell is lost before it can be converted.

Question 6

The most commonly used semiconductor is _____ .

A) boro​n
B) phosphorous
C) crystalline
D) silicon

Question 7

The maximum theoretical efficiency of a single silicon cell is _____ .

A) 98%
B) more than 50%
C) only 29%
D) 18% or less

Question 8

​Solar thermal power plants are the most direct conversion of solar energy into electricity.

Question 9

​Photovoltaic systems suffer numerous losses that reduce the actual electricity produced.

Question 10

​All photovoltaic cells made of silicon produce a voltage of about 0.5 volts per cell regardless of cell size.

Question 11

​Off-grid systems are typically sized smaller than grid-tied systems.

Question 12

_____ solar cells are made from molten silicon that is poured into a mold, cooled, and sliced into thin wafers.

A) Polycrystalline
B) Monocrystalline
C) Amorphous
D) Nonsilicon

Question 13

​When a material absorbs the electromagnetic energy of light, the energy excites electrons from their usual positions in atoms to higher energy states, where they are more able to move around.

Question 14

Photovoltaic modules usually consist of _____ individual cells, each connected in series to its neighbors, to create a total voltage of about _____ volts.

A) 18-36; 36-72
B) 24-36; 12-60
C) 36-72; 18-36
D) 12-60; 24-36

Question 15

Monocrystalline cells are the most efficient of all silicon cells, converting _____ of the arriving solar energy into electricity.

A) 15%-20% or mor​e
B) at least 25%
C) 25%-30%
D) no less than 30%

Question 16

​Monocrystalline cells are the least expensive to manufacture and contain the least amount of embodied energy.

Question 17

_____ metering records the difference between the excess solar electricity delivered to the grid and the utility-produced electricity drawn from the grid.

A) Grid
B) Net
C) Efficiency
D) Differential

Question 18

​The most commonly used semiconductor is silicon.

Question 19

​The top surface of the p-type semiconductor is textured and coated to reduce reflection.

Question 20

Batteries for off-grid systems have batteries that last _____ .

A) approximately 10-12 years
B) no more than 5 years
C) more than 15 years at minimum
D) only 7-9 years on average

Question 21

In practice, photovoltaic systems suffer numerous losses that reduce the actual electricity produced by _____ of the potential power output.

A) no more than 5%
B) approximately 15%
C) as much as 20% or more
D) no less than 50%

Question 22

Which of the following statements is true regarding fixed-mount photovoltaic arrays?

A) They have moving parts that need lubrication, routine maintenance, and replacement of worn gears.
B) Energy production varies greatly for sites with morning and evening shade.
C) They permit building-integrated systems such as photovoltaic roofing shingles.
D) They are not recommended for off-grid applications.

Question 23

Which of the following household items is likely to have the most power consumption in a typical day?

A) electric clock
B) iron
C) table fan
D) TV

Question 24

Compared to a fixed array that is manually adjusted each season to face the sun, dual-axis trackers _____ energy over the course of the year.

A) can produce 30%-35% more
B) produce approximately 25% less
C) produce at least twice as much
D) significantly reduce the production o​f

Question 25

Tracking arrays _____ .

A) expose the greatest possible area to the sun's energy
B) increase reflection caused by oblique illumination
C) can be placed on a pole 4 feet above the ground
D) cannot reposition in the absence of sunlight