Solar Electric Terminology

Amorphous thin film: Materials that produce Solar energy that are made by depositing a thin layer of PV material onto plastic, glass or a metallic foil.

Azimuth: This describes the sun’s location on a horizontal plane that runs from east to west. The sun’s azimuth will change from morning to night as it rises in the east, crosses to the south, and sets in the west. Optimal production for PV system would be attained at an orientation between 180 and 270 degrees.

Building integrated PV array (BIPV): Solar electric arrays that are integrated into the design of the building. This can be accomplished by constructing an awning with modules, or using Solar roof tiles that seamlessly integrate into a roof.

solar energy panel

 

Types of Solar energy systems

Grid tied with battery backup: A grid tied PV system that has battery storage as a backup in case the grid goes down. This type of system will supply instant backup power on selected circuits.

Off Grid: A PV Solar system that is not connected to the electric grid. These systems require battery storage to supply power when the sun is not shining.

On Grid or Grid tied: A PC solar system that is tied in to the electric grid and uses the grid as a back up instead of battery storage or a generator.

Passive Solar: A system that captures the sun’s energy and uses the energy as heat. This type of system can heat water for pools and the inside of a home, or the home itself using south facing glass and strategically placed thermal mass to capture the sun’s energy stored as heat.

 

Common electric terms

AC power: The power supplied by the electric grid.

Current: The flow of electrons in a circuit measured in amps.

DC power: The power supplied by an inverter that is then converted to AC power for use in your home or business.

Energy: The actual work done by electricity measured in watt hours and kilowatt hours. Measuring the rate of power times the amount of time flowing.

KW: One thousand watts. A unit of power.

Kilowatt-hour (kWh): The amount of energy or electricity needed to burn a 100 watt incandescent light bulb for ten hours. One kilowatt equals 1,000 watts.

Load: The amount of electric power used by any electric unit or appliance at a given time.

Peak output: A measurement describing the maximum power produced by a PV array under ideal cloudless conditions.

Pitch: The angle or the steepness of the roof or slope measured in degrees.

Power: The rate of delivery of electricity.

Voltage: The measurement of the force or pressure of the current.

Crystalline Solar cells: The most common PV cells today. These solar building blocks are wafer thin and generally made of Silicon. Two main types, mono and poly crystalline.

CSI: California Solar Initiative. California’s rebate incentive program that promotes solar electric installations.

LEED: A voluntary rating system set up to promote the design and construction of higher energy efficiency in "green homes". The LEED rating system is the nationally recognized standard for green building.

Net metering: An arrangement with your utility where you bank the energy produced by your Solar array, receiving credit for excess energy produced. Generally a 12 month agreement that allows the power producer to use the grid as a back up source of energy for cloudy days and at nights. Your meter goes backward and forward, recording energy used by your home and produced by your home.

Power purchase agreement (PPA): An agreement for the sale of electricity from one party to another that typically involves third party financing.

 

PV system power rating

CEC-AC: The energy produced by a PV system after module and inverter efficiencies have been accounted for. This is the rating that California CSI uses to calculate rebates.

Insolation: The amount of Solar irradiation falling on an area usually expressed in kilowatt -hours per square meter.

Irradiation: The amount of energy falling on an area or the solar power incident. Irradiance multiplied by time equals Insolation.

Power: The rate of delivery of electricity.

PTC: The rating of a module in "real world" conditions based on tests set up by the California Energy Commission.

Standard Test Conditions (STC): The DC output rating of Solar modules, under factory conditions, used to rate module outputs from manufacturer for comparison.

Solar electric system components (listed in order of the progression of the components through the system design):

Combiner box: A fused utility box where wire from strings is reduced to a conduit run to the inverter.

Inverter: The component of the PV system that converts DC electricity to more commonly used AC electricity.

DC disconnect: A means of shutting off the flow of DC current from the array to the inverter to allow for maintenance or troubleshooting.

Photovoltaic cells(PV): Solar cells convert sunlight directly into electricity. Solar cells are made of semi conducting material (silicon based) that is similar to materials used to make computer chips. Sunlight is absorbed by this material which knocks electrons loose from their atoms. This allows the electrons to flow through the silicon layer to produce DC electricity. The PV process converts photons of light into electricity or voltage.

Solar module: Also called a Solar "panel," is comprised of Solar PV cells.

Solar array: A series of modules in a group of strings.

String: A sub group of modules in an array interconnected in a series.

Time of use rates: Electricity pricing structure that varies depending on the time periods in which electricity is used. Higher prices are charged during utility peak-load times, lower prices at off and part-peak times.

 

Common electric terms

AC power: The power supplied by the electric grid.

Current: The flow of electrons in a circuit measured in amps.

DC power: The power supplied by an inverter that is then converted to AC power for use in your home or business.

Energy: The actual work done by electricity measured in watt hours and kilowatt hours. Measuring the rate of power times the amount of time flowing.

KW: One thousand watts. A unit of power.

Kilowatt-hour (kWh): The amount of energy or electricity needed to burn a 100 watt incandescent light bulb for ten hours. One kilowatt equals 1,000 watts.

Load: The amount of electric power used by any electric unit or appliance at a given time.

Peak output: A measurement describing the maximum power produced by a PV array under ideal cloudless conditions.

Pitch: The angle or the steepness of the roof or slope measured in degrees.

Power: The rate of delivery of electricity.

Voltage: The measurement of the force or pressure of the current.

Crystalline Solar cells: The most common PV cells today. These solar building blocks are wafer thin and generally made of Silicon. Two main types, mono and poly crystalline.

CSI: California Solar Initiative. California’s rebate incentive program that promotes solar electric installations.

LEED: A voluntary rating system set up to promote the design and construction of higher energy efficiency in "green homes". The LEED rating system is the nationally recognized standard for green building.

Net metering: An arrangement with your utility where you bank the energy produced by your Solar array, receiving credit for excess energy produced. Generally a 12 month agreement that allows the power producer to use the grid as a back up source of energy for cloudy days and at nights. Your meter goes backward and forward, recording energy used by your home and produced by your home.

Power purchase agreement (PPA): An agreement for the sale of electricity from one party to another that typically involves third party financing.