Photovoltaic Systems 2 Test

Question 1

A distributed-generation system may serve as the only source of power for a consumer, or as back-up or supplemental power for a utility grid connection

Answer 1

True

Question 2

Portable PV systems can never be used while in motion

Answer 2

False

Question 3

Supplemental-power pv systems offset a portion of the power needed from the utility, resulting in lower electricity bills.

Answer 3

True`

Question 4

PV power plants can be located closer to populated areas than can conventional power plants because they do not involve hazardous materials or cause air, water, or noise pollution.

Answer 4

True

Question 5

Solar radiation is a highly variable resource and significant differences exist among regions in the United States.

Answer 5

True

Question 6

It is never advantageous to face an array in a direction other than due south.

Answer 6

False

Question 7

Diesel engines are well suited for constant loads, whereas gasoline engines can respond quickly to changing loads.

Answer 7

True

Question 8

Direct-coupled systems include the fewest components, but can be the most complex PV systems to design properly due to the lack of energy storage or system control.

Answer 8

True

Question 9

A hybrid system is a PV system that can operate in either utility-interactive or stand-alone mode, and uses battery storage.

Answer 9

False

Question 10

For most PV devices, a high operating temperature significantly increases voltage.

Answer 10

false

Question 11

The maximum number of modules that may be connected in a series string is limited, in part, by the maximum system voltage rating of the modules and other components.

Answer 11

true

Question 12

Breakdown voltage is the minimum reverse-bias voltage that results in a rapid increase in current through an electronic device.

Answer 12

true

Question 13

Overcharge is the ratio of applied charge to the resulting increase in battery charge.

Answer 13

true

Question 14

A PV system can be configured to charge multiple separate battery banks with a single array.

Answer 14

true

Question 15

A reactive load is a load that keeps voltage and current waveforms in phase.

Answer 15

false

Question 16

Pulse-width modulation (PWM) is a method of simulating waveforms by switching series device ON and OFF at high frequency and for variable lengths of time.

Answer 16

True

Question 17

Interconnection standards require interactive inverters to maintain an output power factor between 0.95 leading and 0.95 lagging.

Answer 17

True

Question 18

Hybrid-system sizing calculations must use the worst-case load-to-insolation months for sizing.

Answer 18

False

Question 19

Ground-mounted arrays generally offer less flexibility than building-mounted arrays in the locations and orientation of arrays.

Answer 19

False

Question 20

Single-axis tracking mounts follow the sun exactly as it moves across the sky.

Answer 20

False

Question 21

Ground foundations for rack mounts typically include concrete footers.

Answer 21

True

Question 22

A blocking diode is a diode used to pass current around, rather than through, a group of PV cells or modules.

Answer 22

False

Question 23

All utility-interactive inverters must be able to detect power outages and discontinue transfer of power until the utility system returns to normal operation.

Answer 23

True

Question 24

Every state has established rules regarding interconnection and metering.

Answer 24

False

Question 25

The CE Mark indicates compliance with North American safety standards or installation codes.

Answer 25

False

Question 26

A maintenance log is a checklist of all required regular maintenance tasks and their maximum intervals.

Answer 26

False

Question 27

Incentive programs are intended to be long-term efforts promoting renewable-energy systems.

Answer 27

False

Question 28

Life-cycle cost for PV systems is typically evaluated using a 5 to 10-year period.

Answer 28

False

Question 29

The life-cycle cost for any energy system is the sum of the present values of the various types of cost over its expected lifetime, minus the present value of the system at the end of its lifetime.

Answer 29

True

Question 30

Incentives can affect total life-cycle cost differently depending on how and when they are applied.

Answer 30

True

Question 31

Portable PV systems power mobile loads such as ____.

Answer 31

vehicles, temporary signs, lighting, and handheld devices.

Question 32

Solar _____ is the total amount of solar energy accumulated on an area over time.

Answer 32

irradiation

Question 33

_____ is the angle between the direction a compass needle points (toward magnetic north) and true geographic north.

Answer 33

Magnetic declination

Question 34

The DC power output of an array during low insolation should provide about ____% of the minimum AC power requirement.

Answer 34

130

Question 35

A(n) _____ is a device that converts DC power into AC power.

Answer 35

inverter

Question 36

The voltage and current output from an array can vary with _____.

Answer 36

temperature, irradiance, and load.

Question 37

A(n) ____ switch allows an electrical system to be switched from a primary power source to an alternate power source in order to keep critical loads operating.

Answer 37

transfer

Question 38

A (n) _____ is a PV device consisting of a number of individual cells connected electrically, laminated, encapsulated, and packaged into a frame.

Answer 38

module

Question 39

_____charging is battery charging at a low charge rate that maintains full battery charge by counteracting self-discharge.

Answer 39

Float

Question 40

_____ is a condition of flooded lead-acid cells in which the specific gravity of the electrolyte is greater at the bottom than the top.

Answer 40

Stratification

Question 41

_____affects battery charging characteristics, so some charge controllers automatically adjust setpoints to compensate for this factor.

Answer 41

Temperature

Question 42

A(n) _____ is a device that transfers energy from one circuit to another through magnetic coupling.

Answer 42

Transformer

Question 43

Installed nominal operating cell temperature (INOCT) for ____-mounted modules is the highest among building mounting systems.

Answer 43

direct

Question 44

A(n) _____ photovoltaic array is a fixed array that replaces conventional building materials with specially designed modules that also performs an architectural function.

Answer 44

building-integrated

Question 45

A _____ mount is a type of array mounting system where modules are installed at an elevation on a pedestal.

Answer 45

pole

Question 46

A(n) ----- mount is an array mounting system that automatically orients the array to the position of the sun.

Answer 46

sun-tracking

Question 47

A(n) _____-bolt is a fastener that hooks around a secure support structure and has a threaded end that is used with a nut to secure items.

Answer 47

J

Question 48

Improper electrical integration can cause _____.

Answer 48

poor performance, component damage, and electrical shock hazards.

Question 49

For PV source circuits, the maximum current is ____% of the sum of the short-circuit current rating of parallel-connected modules.

Answer 49

125

Question 50

A _____ box is a junction box used as the connection point for two or more circuits.

Answer 50

combiner

Question 51

A(n) _____ agreement is a contract between a distributed power producer and an electric utility that establishes the terms and condition for the interconnection.

Answer 51

interconnection

Question 52

In some jurisdictions, _____ are allowed to aply for permits and act as their own contractor without having a license.

Answer 52

property owners

Question 53

A(n) _____ is permission from the AHJ that authorizes construction work to begin and establishes the inspection requirements, but does not represent an approval of compliance with codes and standards.

Answer 53

permit

Question 54

A(n) _____ is an evaluation of system design documentation as part of the permitting process.

Answer 54

plans review

Question 55

The electrolyte in flooded, open-vent batteries must be maintained at proper levels by periodically adding _____.

Answer 55

water

Question 56

_____ is the continuous measurement of electrical, environmental, or battery parameters.

Answer 56

Monitoring

Question 57

_____ is a troubleshooting step that involves determining which part of the system is not working properly and observing the conditions that may have contributed to the cause.

Answer 57

Observation

Question 58

The _____ is the monetary value of a system at the end of its expected useful lifetime.

Answer 58

Salvage value

Question 59

The most significant costs in the life cycle of a PV system are the ____ costs.

Answer 59

initial

Question 60

The _____ period is the amount of time required for the avoided costs from an alternate energy source to match the cost of the chosen energy-production system.

Answer 60

payback

Question 61

A(n) _____ may be directly employed by an integrator, or by an electrical contractor who specializes in PV installations.

Answer 61

installer

Question 62

Solar _____ is the angle between the equatorial plane and the line joining the centers of the sun and Earth (in the ecliptic plane).

Answer 62

declination

Question 63

It is sensible to apply energy _____ measures before installing PV systems because their initial costs and payback periods are substantially less than increasing the size of the PV system.

Answer 63

conservation

Question 64

_____ is the measure of the electrical storage potential of a battery or cell.

Answer 64

Capacity

Question 65

A(n) _____ is a device that regulates battery charge by controlling the charging voltage and/or current from a DC power source, such as a PV array.

Answer 65

charge controller

Question 66

The _____ is the voltage difference between the voltage regulation setpoint and the array reconnect voltage setpoint.

Answer 66

voltage regulation hysteresis

Question 67

The nominal voltage and rated _____ of the selected battery are used to determine the configuration of the battery bank.

Answer 67

capacity

Question 68

_____ corrosion is an electrochemical process that causes electrical current to flow between two dissimilar metals, eventually corroding one of the materials.

Answer 68

Galvanic

Question 69

The best weather-sealing method uses _____ and rubber boots to seal around roof penetrations.

Answer 69

flashings

Question 70

Inverter power output is limited by the capacity of the PV array, the inverter output rating, and _____.

Answer 70

temperature

Question 71

Pre-drywall _____ are required when any electrical or mechanical work will become permanently concealed behind walls.

Answer 71

inspections

Question 72

Measuring electrical parameters is the most important type of _____.

Answer 72

monitoring

Question 73

A system is broken down into functional areas called _____.

Answer 73

subsystems

Question 74

_____ is a troubleshooting step that is conducted primarily through inspection and testing.

Answer 74

investigation

Question 75

Cost _____ is a comparison of two or more options that considers both the cost and value of each.

Answer 75

analysis