Test 9

Question 1

PV-system sizing strategy starts at the array and proceeds backward to the load side.

Answer 1

False

Question 2

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

Answer 2

False

Question 3

Underestimating loads will result in a PV system that is too small and cannot operate the loads with the desired reliability.

Answer 3

True

Question 4

A slightly oversized inverter is usually recommended to account for potential future load additions.

Answer 4

True

Question 5

Some power is lost in the process of converting DC energy to AC energy.

Answer 5

True

Question 6

The DC-system voltage is established by either the array voltage in battery-based systems or the battery-bank voltage in interactive systems.

Answer 6

False

Question 7

Greater autonomy requires larger and costlier battery banks.

Answer 7

True

Question 8

Low operating temperatures and high discharge rates increase battery capacity.

Answer 8

False

Question 9

Generally, the number of parallel battery connections should be limited to no more than 3 to 4 strings.

Answer 9

True

Question 10

The number of series-connected modules in each array string is determined by diving the rated array current by the selected module’s current output.

Answer 10

False

Question 11

____ systems can be sized according to either the stand-alone methodology or the interactive methodology.

Answer 11

Bimodal

Question 12

Sizing PV systems for stand-alone operation involves ____ set(s) of calculations.

Answer 12

four

Question 13

____ may be used to help establish existing load requirements.

Answer 13

Measurements, meter readings, and electric bills (all of the above)

Question 14

____ is the percentage of time a load is operating.

Answer 14

Duty cycle

Question 15

The ____ ratio is the ratio of electrical energy demand to average insolation during a period.

Answer 15

critical design

Question 16

The DC voltage for battery-based PV systems is usually an integer multiple of ____V.

Answer 16

12

Question 17

System ____ is the percentage of time over an average year that a stand-alone PV system meets the system load requirements.

Answer 17

availability

Question 18

Most PV systems use deep-cycle lead-acid batteries, which can be safely discharged to about ____%.

Answer 18

80

Question 19

The ____ is the portion of load operating power that comes from the battery bank over the course of a day.

Answer 19

load fraction

Question 20

____ is the accumulation of dust and dirt on an array surface that shades the array and reduces electrical output.

Answer 20

Soiling

Question 21

____-system sizing is very flexible because the utility can supply extra energy to the system loads and receive excess energy from the PV system.

Answer 21

Interactive

Question 22

In a(n) ____ system, the presence of multiple power sources allows for a smaller array while system reliability is improved.

Answer 22

hybrid

Question 23

Electrical energy consumption is based on the electrical ____ demand over time.

Answer 23

power

Question 24

If the loads are constant over the entire year, the critical design month is the month with the lowest ____ on the array surface.

Answer 24

insolation

Question 25

____ is the amount of time a fully charged battery system can supply power to system loads without further charging and is expressed in days.

Answer 25

Autonomy

Question 26

Of the critical design months for each orientation, the one with the smallest ____ is the best choice.

Answer 26

critical design ratio

Question 27

The average battery bank ____ is determined from the total operating time over the period of autonomy.

Answer 27

discharge rate

Question 28

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

Answer 28

capacity

Question 29

For ____ systems, the array must be sized to produce enough electrical energy to meet all the load requirements during the critical design month.

Answer 29

stand-alone

Question 30

The rated array voltage is multiplied by ____ to ensure that the maximum-power voltage is sufficient to charge the battery bank.

Answer 30

1.2