Photovoltaic Systems 2 Test Flashcards
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
True
Portable PV systems can never be used while in motion
False
Supplemental-power pv systems offset a portion of the power needed from the utility, resulting in lower electricity bills.
True`
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.
True
Solar radiation is a highly variable resource and significant differences exist among regions in the United States.
True
It is never advantageous to face an array in a direction other than due south.
False
Diesel engines are well suited for constant loads, whereas gasoline engines can respond quickly to changing loads.
True
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.
True
A hybrid system is a PV system that can operate in either utility-interactive or stand-alone mode, and uses battery storage.
False
For most PV devices, a high operating temperature significantly increases voltage.
false
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.
true
Breakdown voltage is the minimum reverse-bias voltage that results in a rapid increase in current through an electronic device.
true
Overcharge is the ratio of applied charge to the resulting increase in battery charge.
true
A PV system can be configured to charge multiple separate battery banks with a single array.
true
A reactive load is a load that keeps voltage and current waveforms in phase.
false
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.
True
Interconnection standards require interactive inverters to maintain an output power factor between 0.95 leading and 0.95 lagging.
True
Hybrid-system sizing calculations must use the worst-case load-to-insolation months for sizing.
False
Ground-mounted arrays generally offer less flexibility than building-mounted arrays in the locations and orientation of arrays.
False
Single-axis tracking mounts follow the sun exactly as it moves across the sky.
False
Ground foundations for rack mounts typically include concrete footers.
True
A blocking diode is a diode used to pass current around, rather than through, a group of PV cells or modules.
False
All utility-interactive inverters must be able to detect power outages and discontinue transfer of power until the utility system returns to normal operation.
True
Every state has established rules regarding interconnection and metering.
False
The CE Mark indicates compliance with North American safety standards or installation codes.
False
A maintenance log is a checklist of all required regular maintenance tasks and their maximum intervals.
False
Incentive programs are intended to be long-term efforts promoting renewable-energy systems.
False
Life-cycle cost for PV systems is typically evaluated using a 5 to 10-year period.
False
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.
True
Incentives can affect total life-cycle cost differently depending on how and when they are applied.
True
Portable PV systems power mobile loads such as ____.
vehicles, temporary signs, lighting, and handheld devices.
Solar _____ is the total amount of solar energy accumulated on an area over time.
irradiation
_____ is the angle between the direction a compass needle points (toward magnetic north) and true geographic north.
Magnetic declination
The DC power output of an array during low insolation should provide about ____% of the minimum AC power requirement.
130
A(n) _____ is a device that converts DC power into AC power.
inverter
The voltage and current output from an array can vary with _____.
temperature, irradiance, and load.
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.
transfer
A (n) _____ is a PV device consisting of a number of individual cells connected electrically, laminated, encapsulated, and packaged into a frame.
module
_____charging is battery charging at a low charge rate that maintains full battery charge by counteracting self-discharge.
Float
_____ is a condition of flooded lead-acid cells in which the specific gravity of the electrolyte is greater at the bottom than the top.
Stratification
_____affects battery charging characteristics, so some charge controllers automatically adjust setpoints to compensate for this factor.
Temperature
A(n) _____ is a device that transfers energy from one circuit to another through magnetic coupling.
Transformer
Installed nominal operating cell temperature (INOCT) for ____-mounted modules is the highest among building mounting systems.
direct
A(n) _____ photovoltaic array is a fixed array that replaces conventional building materials with specially designed modules that also performs an architectural function.
building-integrated
A _____ mount is a type of array mounting system where modules are installed at an elevation on a pedestal.
pole
A(n) —– mount is an array mounting system that automatically orients the array to the position of the sun.
sun-tracking
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.
J
Improper electrical integration can cause _____.
poor performance, component damage, and electrical shock hazards.
For PV source circuits, the maximum current is ____% of the sum of the short-circuit current rating of parallel-connected modules.
125
A _____ box is a junction box used as the connection point for two or more circuits.
combiner
A(n) _____ agreement is a contract between a distributed power producer and an electric utility that establishes the terms and condition for the interconnection.
interconnection
In some jurisdictions, _____ are allowed to aply for permits and act as their own contractor without having a license.
property owners
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.
permit
A(n) _____ is an evaluation of system design documentation as part of the permitting process.
plans review
The electrolyte in flooded, open-vent batteries must be maintained at proper levels by periodically adding _____.
water
_____ is the continuous measurement of electrical, environmental, or battery parameters.
Monitoring
_____ 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.
Observation
The _____ is the monetary value of a system at the end of its expected useful lifetime.
Salvage value
The most significant costs in the life cycle of a PV system are the ____ costs.
initial
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.
payback
A(n) _____ may be directly employed by an integrator, or by an electrical contractor who specializes in PV installations.
installer
Solar _____ is the angle between the equatorial plane and the line joining the centers of the sun and Earth (in the ecliptic plane).
declination
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.
conservation
_____ is the measure of the electrical storage potential of a battery or cell.
Capacity
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.
charge controller
The _____ is the voltage difference between the voltage regulation setpoint and the array reconnect voltage setpoint.
voltage regulation hysteresis
The nominal voltage and rated _____ of the selected battery are used to determine the configuration of the battery bank.
capacity
_____ corrosion is an electrochemical process that causes electrical current to flow between two dissimilar metals, eventually corroding one of the materials.
Galvanic
The best weather-sealing method uses _____ and rubber boots to seal around roof penetrations.
flashings
Inverter power output is limited by the capacity of the PV array, the inverter output rating, and _____.
temperature
Pre-drywall _____ are required when any electrical or mechanical work will become permanently concealed behind walls.
inspections
Measuring electrical parameters is the most important type of _____.
monitoring
A system is broken down into functional areas called _____.
subsystems
_____ is a troubleshooting step that is conducted primarily through inspection and testing.
investigation
Cost _____ is a comparison of two or more options that considers both the cost and value of each.
analysis
