Question | Answer |
___ is a solar energy technology that uses the unique properties of certain semi-conductors to directly convert solar radiation into electricity | Photovoltaics |
The Vertical angle between horizontal and the array surrface | Array Tilt Angle |
The range of all types of electromagnetic radiation, based on wavelength | Electromagnetic Spectrum |
A representation of the relative thickness of atmosphere that solar radiation must pass through to reach a point on earths surface | Air Mass (AM) |
The Power of solar radiation per unit area | Solar IRRADIANCE |
A plane by a due north-south longitude line through a location on earth and projected out into space | Meridian |
Earth's orbital position when solar declination is zero | Equinox |
A sensor that measures only direct solar radiation in the field of view of the solar disk | Pyrheliometer |
___ is solar energy technology that uses unique properties of certain semiconductors to directly convert solar radiation into electricity. | Photovoltaics |
A solar energy collector that absorbs solar energy on a flat surface without concentrating it, & can utilize solar radiation that is reflected or scattered by clouds and other surfaces. | Flat- Plate Collector |
A buisness that designs builds and installs complete PV systems for particular applications by matching components from various manufacturers | Integrator |
A piece of equipment that consumes electricity | Load |
Maximum annual solar energy gain on a fixed surface is achieved by abilities to the ___ | Lattitude |
___ generation is a system in which many smaller power generating system create electrical power near the point of consumption | Distributed |
___ is credited with discovering the power efect in 1839. | Edmund Becquerel |
__-__ systems are the fastest grounding statement of the PV systems market. | Utility- Interactive |
Solar__ is the angle between the equatorial plane and the rays of the sun | Declination |
A ___ is a sensor that measures only direct solar radiation in the field of view of the solar disk. | Pyrheliometer |
Solar thermal energy systems connect __ into heat energy | Solar Radiation |
__ is the energy that expands outward from a source in the form of waves or particles. | Radiation |
Solar __ is the intensity of solar power | Irradiance |
__ is the solar energy that reaches earths surface over the course of a day. | Insolation |
The 2 major types of radiation reaches the ground are direct and ___ radiation | Diffuse |
The __ law is a physical law that states that the ammount of radiation is proportional to the inverse of the square of the distance from the source. | Inverse Square Law |
___ is also known as top-of-atmosphere (TOA) Radiation | Extraterrestrial |
Makes a system smaller and less expensive | Energy Conservation |
Energy loss due to shading on a thermal panel | Proportionate |
Energy loss due to shading on a pv panel | Disproportionate |
Changes DC to AC | Inverter |
Utility Interactive PV system | simplest and least expensive to produce |
Uses Hydrogen and Oxygen to produce DC electricity | Fuel Cell |
Single device using photons to produce DC power | Module |
Stand alone system with no batteries and no controller | Direct Coupled |
All loads in a typical home | AC Loads |
Produce electricity from the flow and pressure of water ( A Dam) | Micro Hydroelectric Turbine |
Regulates battert charging protecting the battery from over-charging and over- discharging | Charge Controller |
Multiple device connected together in a series or parallel which use photons to produce DC Power | Array |
Continually adjusts the load under changing temperature and irradiance for ___ | MPPT |
Combusts fossil fuels to turn a crankshaft which turns a generator to produce electricity | Engine Generator |
Batteries, Fly Wheels, Super Capaciter | 3 storage devices |
Maximum votage for a PV device under infinate load( No Current
output) | Open Circuit Current |
The highest efficiency for a module at a given irradiance and temperature | Max Power Point |
Temperature affects what? | Affects a modules current |
__ Prevents reversed biased flow | Bypass Diode |
Alike Current Output | Series connected modules |
Maximum current for a PV device under no load (No voltage output) | Short Circuit Current |
When connecting 2 or more series together | Parallel Connected modules |
What are PV cells made of? | Semi-conductors usually Silicon |
Sollar Irradiance affects what in a module | affects Current |
Open circuit Voltage and short circuit current | Relationship on an I-V Curve |
__ Can fix stratification and Sulfation | Equalizing Charge |
Fast charge about80- 90 percent capacity | Bulk Charge |
Decomposition of water into Hydrogen and oxygen | Gassing |
How long a system can run on batteries without further charging ( Usually in days) | Autonomy |
(Trickle) it keeps battery at 100 percent capacity | Float charge |
Conducting Medium which transfers ions between battery cell plates | Electrolytes |
Traction | Best VP Battery |
SLI ( Automotive) | Worst PV Battery |
Percent discharge without hurting a battery ( 80% in deep cycle traction batteries) | Allowable depth of discharge |
The energy storage potential of a battery expressed in Ampere Hours (AH) | Capacity |
Slow Charge (1-3) hours of about 10%- 15% capacity | Absorbtion Charge |
Percentage of withdrawn energy in a battery compared to fully charged | Depth of Discharge |
Ventilation of Hydrogen | Most important feature of a battery enclosure |
Lowers the energy for that charge cycle | Fast Discharge |
CC gives system information through LEDs and/or digital display | Status Information |
what to locate the charge controller next to if the temp. compensation is in the controller | Battery Bank |
CC protects system or loads from high current or bad wiring. | Circuit Protection |
CC gives system information through LEDs and/or digital display | Status Information |
what to locate the charge controller next to if the temp. compensation is in the controller | Battery Bank |
CC protects system or loads from high current or bad wiring. | Circuit Protection |
The battery voltage levels at which a cc performs regulation or switching to the limit the charge or loads | Charge controller set points |
Changes resistance or input voltage of the array for a range of conditions to get MPP | MPPT Charge Controller |
CC interupts or limits the current flow to the battery | Over charge protection |
Keeps a battery fully charged when cold and not overcharged when hot | Temperature compensation |
Operation in parallel with grid | Utility interactive inverter |
CC activates or disconnects loads based on set conditions | Advanced load control |
sophisticated feature does an AC module have that a charge controller has | MPPT |
Changes resistance or input voltage of the array for a range of conditions to get MPP | MPPT Charge Controller |
CC disconnects the load when battery is at low voltage | Over Discharge Protection |
Operation in parallel with grid | Utility interactive inverter |
sophisticated feature does an AC module have that a charge controller has | MPPT |
Connect to batteries, independant of array and grid | Stand alone Inverter |
90%- 95% | Iteractive inverter efficiency rating |
interactive or stand alone mode ( not at the same time) | Bimodal inverter |
75%- 90% | Stand alone inverter efficiency rating |
Wave form required for AC loads | Sine Wave |
Replaces DC junction box, less components- easier design and install, interactive only. could cost more.. | AC module Inverter |
t700 w for small residential to over 500 kw for a large commercial and utility | Power ranges for interactive inverters |
__ Volts is the Max output-circuit voltage for 1 and 2 family homes? | 600 Volts |
___ ___ __ is used to calculate max pv output voltage per NEC? | Temperature Correction Factor |
___% is used to determine maximum pv circuit current | 125% (1.25) |
What 2 places can you look for temperature correction factors when calculating open circuit voltage from an array? | Module manufacturer specifications or NEC 690.7 |
For battery systems max inverter current can exceed nominal ratings under what condition? | When the highest input current is matched with the lowest inverter orerating voltage. |
What system do we use to give wire (conductor) size? | American Wire Guage (AWG).. larger numbers is smaller wire (Vice Versa) |
What is Ampacity? | The current a wire can carry without exceeding it's temp. rating (ability)(Ampacity is affected by temp, current, and AWG) |
What is derating? | Reduces a wires rated ability (ampacity) |
What does temperature do to a wires ampacity? | Temp. reduces (derates) a wires rated ability (ampacity) |
What should be done when there are more than 3 wires in a conduit longer than 24 inches? | Further reduce (derate) the wires rated aility (ampacity) |
What is an acceptable voltage drop? | 3% (not required) |
What 3 prp[erties define wire insulation? | Temp, Enviorment, & Location |
What type of wire is used for battery connections? | Finely stranded for flexibility. |
What current carrying connection does not need to be made within a junction box? | Module to Module connections |
What is a pv combiner box used for? | a parallel connection point for 2 or more array circuits. |
What does a Blocking Diode do? | Prevents reversed flow from batteries to the array. |
What type of conduit should be used for DC when inside a building? | Metal Conduit (EMT, RMC, IMC) |
What over current devices are used in PV? | Fuses and Circuit Breakers |
What over current device rating is required for PV circuits? | 125% (1.25) |
When can a Back-Fed circuit breaker be used for a given device? | Any device marked as suitable (rated) Any device not marked Line or Load (NEC 690.10 E) |
What device can be used for a disconnect? | A switch or a circuit breaker. |
What should you be aware of when switching off an AC disconnect? | The inverter will be off, but the rest of the DC side could still be energized |
Where should you locate the AC disconnect for an interactive PV system? | Near the main utility panel and service disconnect. |
What does Grounding do? | To provide a path for a fault currents to protect people and equipment. |
What is a Grounding Electrode? | A conductive rod, plate or wire burried in the ground for grounding. |
What parts of a PV system are typically grounded? | AC, DC & Array |
What is a ground fault? | An undesireable condition of current flowing through the grounding conductors. |
What device protects PV arrays from ground fault? | Ground Fault Detect & Interrupt (GFDI) |
What types of connectors are used to ground an ,array? | Stainless steel connector, a copper plated lug screw on a bare copper wire. |
When do you know not have enough to ground an arraycircuit( Source of Output)? | under certain conditions as specified in the (NEC 690.35) |
What part of the world typically does not ground array circuits ( source & output)? | Europe |
What safety device can be installed to protect PV systems? | Lightning protection & Surge Arrestors. |
PV battery system requirements are found in which code? | NEC 690 |