Solar Glossary: 100+ Terms to Shed Some Light on the Solar Industry

Reading about the solar industry and come across a term you don’t recognize? We built this solar glossary to help those interested in the solar industry or home solar panels better understand the terms, geography, science, and lingo of the trade. You can use the letters at the top of the solar glossary to jump to a corresponding section to look up words and their meanings.

AC, or Alternating Current, is a form of electric current that is commonly used to power homes and has a signature sine-wave shaped current. It is primarily known for being the type of current championed by Nikola Tesla. Learn More Here
Alternating Current
See AC.
Alternative Energy
Alternative energy usually refers to electricity generated through renewable power sources, such as wind, tide, or solar.
An ampere is equal to one coulomb of electricity per second.
Ampere Hour
An ampere hour meter is a device that monitors and records ampere hours in a home.
Annual Solar Savings
Annual solar savings is defined as the total amount that a homeowner can save per year in utilities expenses by installing solar panels, as well as any additional savings gained by the Federal Solar Tax Credit and local or state incentives. Learn More Here
An anode is the negatively charged electrode through which an electrical current enters an electrical device. A common mnemonic to remember the difference between an anode and cathode is ACID – Anode Current Into Device.
An array is a linked set of photovoltaic modules that work together to convert solar energy into electricity. See photovoltaic array.
Array Current
An array current is the electrical current produced by a photovoltaic array when it is exposed to the sunlight.
Array Operating Voltage
The array operating voltage is the voltage at which a solar array is designed to generate at ideal operating conditions.
See Azimuth Angle.
Azimuth Angle
An azimuth angle is a measurement to denote the angle between an observer and the sun, relative to the local horizon. At its most simple, the azimuth angle is the compass direction from which sunlight is shining. Learn More Here
Base Load
Base load refers to the minimum amount of electrical demand on a system over a 24-hour period. Also known as continuous load. For instance, consider a house: Even when you are not home, you will still have appliances running such as refrigerators or heating. This base demand that is always present is the base load.
A battery is a storage device for electrical energy, typically in a chemical solution, that can be used as a source of power. Learn More Here
Battery Capacity
Battery capacity is measured in terms of amp-hours and is defined as how long a battery would be able to supply power to a device before the battery voltage is dropped below a certain level – usually 25 or 50%.
Battery Cell
Also called voltaic cells, a battery cell is an electrochemical cell in which an electric current is generated through spontaneous chemical reactions.
Battery Cycle Life
Battery cycle life is the typical number of charge and discharge cycles that a battery can undergo before it reaches the end of its useful life. This number of charge/discharge cycles is a function of the conditions under which the battery was used, the ambient temperature, and the method used to charge the battery. Learn More Here
Battery Energy Capacity
Battery energy capacity refers to the total amount of energy that can be stored in a battery when fully charged. Also see Battery Life.
Battery Energy Storage
Battery energy storage refers to a rechargeable battery system designed to store energy collected by solar arrays and provide that energy to a home of business when required.
Battery Life
Battery life is the length of time a device can continue to work before it needs its battery to be recharged. Learn More Here
Typically, capacity refers to the total amount of electrical load that a generator or system can handle without losing service. Usually measured in terms of megawatts when referring to the electrical grid.
Capacity Factor
Capacity factor refers to the ratio between the actual amount of energy produced in a system compared to the theoretical maximum amount of power possible in a system.
A cathode is the positively charged electrode through which an electrical current leaves an electrical device. A common mnemonic to remember the difference between an anode and cathode is ACID – Anode Current Into Device. Also see Anode.
A unit in an electrical circuit that is used to create an electrical current by a means other than that of a conductor in a magnetic field. A solar cell is an example of this.
Cell Junction
The cell junction in a solar cell is the area where the n-type and p-type semiconducting material come together. This junction is where an electrical charge is created when the semiconducting material is struck by light.
Charge can either refer to the current status of a battery (such as 50% charged), or more commonly refer to the physical property of matter that would cause it to react when placed in an electromagnetic field. The two types of charge are positive and negative that are carried by protons and electrons. When there is no charge at all, this is referred to as ‘neutral’.
Charge Carrier
A charge carrier is a particle that carries an electric charge. Usually referring to electrons, ions, and holes when used in the context of electrical circuits or solar systems.
Charge Controller
A charge controller is a device which limits the rate of charge or discharge of electrical energy from a battery. Also referred to as a charge regulator or battery regulator. Learn More Here
Charge Factor
The number of hours that a battery can be charged continuously at a consistent current without damage to the battery.
Charge Rate
Charge Rate is the amount of energy added to a battery over a given unit of time. Often measured in Amps. Learn More Here
Community Solar
Community solar refers to a solar power plant that is shared across multiple end users, or an entire community, rather than just one household or business. Sometimes this takes the form of actual electricity being delivered to a household, while in other forms this results in credits being applied to a households electrical bill for grid power.
A conductor is a material that allows electricity to flow through it.
Contact Resistance
Contact resistance refers to the resistance added to a system by contacting electrical leads and connections rather than the intrinsic resistance found in a system.
A converter is a device that converts electricity from one form to another.
Current, as applied to electricity, refers to an electric current which is the movement of subatomic charged particles, ions, or holes flowing in a particular direction.
Cutoff Voltage
See ‘Low Voltage Cutoff’
A cycle is the change in an electrical sine wave from zero to its maximum value, back to zero, to its minimum value, then back to zero again. This would look similar to a sideways ‘S’ on a graph.
Direct current, or DC, is a type of power current used by many small appliances and off-grid applications. Learn More Here
DC-to-DC Converter
A DC to DC converter is a device that converts direct current power from one voltage level to another and may boost the total power output from a solar array by up to 30%.
Days of Storage
The number of days that a system will be able to provide enough power without additional energy input when disconnected from the grid.
Deep-Cycle Battery
A deep-cycle battery is a battery (usually lead-acid) that id designed to be 80% or more discharged before being recharged. Deep-cycle batteries are ideal for marine, rv, and off-grid solar applications.
A dendrite, as used in the solar industry, is a crystalline mass with a branching treelike structure. This might be seen in crystalline silicon.
Depth of Discarge
Depth of discharge refers to the degree to which a battery can be discharged relative to its total capacity, while a deep discharge specifically refers to a battery that has been fully discharged.
A diode is a semiconducting device that only allows an electrical current to flow in one direction through it to prevent current from flowing in the opposite direction and damaging sensitive electronics.
Direct Beam Radiation
Also called Direct Radiation, direct beam radiation is the term for the solar radiation traveling in a straight line between the sun and the surface of the Earth.
Direct Current
See DC.
Discharge, when referring to electricity, is the release of electrical energy from one device or state to another. Such as the release of electrical energy from a battery into an appliance.
Discharge Factor
The number of hours that a battery can be discharged without causing damage to the battery.
Discharge Rate
Discharge rate is the rate at which a battery can be discharged over a certain period of time at a given current load. Measured in amp-hours. Learn More Here
Distributed Power
A distributed power system, also referred to as decentralized energy or on-site generation, is when electricity is generated by a number of small, grid-connected devices that are located close to the loads that they serve. Often with capacities of 10 megawatts of less.
Also referred to as a power outage. The time that a power grid is unavailable or damaged and unable to supply electricity. May refer to the grid as a whole or to specific components, such as a solar array, that are local to a home.
Dry Cell
A dry cell battery is a form of battery in which the electrolyte is fully absorbed into a solid form. This allows the battery to be used in any orientation as well as prevent spillage. Most commonly used to power small electronics.
Duty Cycle
In a device that operates intermittently rather than continuously, the duty cycle refers to the time that is actually occupied as a percentage of total available time.
Duty Rating
The total amount of time that an inverter can produce electricity at a full power rating.
Efficiency, in regard to electricity, refers to the ability of a system to reduce the required power demands while still meeting all power needs.
Electric Circuit
An electric circuit consists of a power source, a means for transmitting that power, and a device that consumes that power. This could be as simple as a battery connected to a lightbulb with wires, or as complex as an entire city producing and consuming power with large-scale devices.
Electric Current
See current.
Electrical Grid
The electrical grid is the system of transmission lines, power stations, and all other hardware that connect electrical producers to homes and businesses.
Electricity is a form of energy that results from the presence of either positively or negatively charged particles.
Electrochemical Cell
An electrochemical cell is a device that generates electrical energy by harnessing chemical reactions. Most wet-cell batteries (such as car batteries) are electrochemical cell batteries.
An electrode is a conductor through which electricity is able to enter or leave a device. Typically carries an electrical current into a nonmetallic part of a circuit.
Also known as electroplating. A process that uses an electrical current to deposit a dissolved metal onto an object to create a new metal coating.
An electrolyte is a substance that, when mixed with water, produces a highly conductive solution. Some examples of efficient electrolytes include sodium, potassium, chloride, magnesium, or phosphate.
An electron is a negatively charged subatomic particle that, together with neutrons and protons, make up atoms. In electrical systems, current is generated when electrons move from atom to atom or from negatively charged anodes to positively charged cathodes.
Electron Volt
Electron volt is a unit of energy typically used in nuclear physics. One electron volt is equal to the energy gained by an electron when the electrical potential of that electron increases by one volt, or 1.602 x 10^-19 joule.
Energy is the kinetic and potential energy in the protons and electrons of an atom that can be used to apply force or do work.
Federal Investment Tax Credit
Federal investment tax credits are a federal program that incentivizes businesses to invest in various programs and technologies through a temporary reduction in taxes proportionate to their total investment costs. Often used in relation to solar installations.
Fixed-Tilt Array
A fixed-tilt array is an immobile solar array that is mounted at a fixed angle to the sun and are very simple to design and construct.
Flat Plate Array
A flat-plate array is a photovoltaic array that consists of flat panels rather than shaped panels.
Flat-Plate Photovoltaics
Flat-plate photovoltaics are a type of photovoltaic array that consists of flat solar panels as opposed to concentrating modules. Learn More Here
Full Sun
Full sun is defined as an area that gets more than 6 hours of direct sunlight per day. Learn More Here
Gel-Type Battery
A gel-type battery has a gel-medium electrolyte composed of sulfuric acid mixed with fumed silica.
One gigawatt is defined as the power equivalent of one billion watts.
The grid, or electrical grid, refers to the entire system of infrastructure that generates, transmits, supplies, and stores power between producers and consumers.
Grid Lines
Grid lines refer to the lines shown on a chart that help the viewer understand the values represented by points on the graph. Grid lines may be minor or major lines with or without labels.
Grid Parity
Grid parity refers to the point at which the cost to generate solar energy is approximately equal to the cost to generate the same amount of fossil-fuel based electricity.
Grid-Connected System
A grid-connected system is a solar system that is tied into the grid and feeds electricity directly into the grid.
Grid-Interactive System
A grid-interactive system generates solar power to charge batteries for use during power failures and adds electricity to the grid when there is excess.
Grid-Mounted Solar
A grid-mounted solar system is a solar power array that is connected to the grid and feeds in electricity.
A heterojunction is the point at which two different materials meet. For instance, when n-type and p-type semiconductors meet, this region of meeting would be called a heterojunction.
I-Type Semiconductor
See ‘Intrinsic Semiconductor’
The amount of solar radiation that is striking a given area on the Earth.
Intrinsic Semiconductor
An intrinsic semiconductor, also called a pure semiconductor or i-type semiconductor, is a semiconducting material that does not require doping to sustain an electrical current.
An inverter, or power inverter, is a device which converts direct current energy to alternating current energy so that it can be used by typical household appliances. Learn More Here
An ion is an atom that has either a positive or negative charge due to an imbalance of either protons or electrons. Positively charged ions are called cations, while negatively charged ions are called anions.
See Solar Irradiance.
A joule is one 3600th of one watt-hour.
Junction Box
A junction box in a solar system houses all the electrical components of a solar panel that connect the diodes to the rest of the solar system and protects them from the weather.
Junction Diode
A junction diode is a device that converts one type of electricity (ac) into another type (dc) at the point that two opposing charges meet, such as n-type and p-type semiconductors. All solar cells are considered to be junction diodes.
A kilowatt is a unit of power equal to 1000 watts.
The power equivalent to 1,000 watts of power expended over one hour.
Lead-Acid Battery
Lead-acid batteries are batteries made of lead plates and sulfuric acid. Lead-acid batteries were invented in 1859 and is the earliest type of rechargeable battery. They have very low energy to volume ratios, but a very high surge-current capability.
Levelized Cost of Energy
The levelized cost of energy is a measure of the average net cost of electricity generation for an electrical generator over its entire working lifetime. This metric is usually a part of investment planning for larger scale developments.
Life-Cycle Cost
Life cycle cost refers to the total cost of a solar panel and its affiliated equipment over its entire life cycle, including installation, maintenance, and operating costs.
Light Trapping
Light trapping refers to the quality of many solar devices in which a photon that enters the device may travel a greater distance than the device is thick due to carefully engineered reflections.
Liquid Electrolyte Battery
A liquid electrolyte battery is a battery in which the electrolyte is a liquid. This is most commonly found in lithium-ion batteries.
Load refers to the amount of electricity in a circuit at any given time. This may be a local home circuit or refer to the entire electrical grid. When wiring electronics, this refers to the direction that the power will be supplied from.
Load Circuit
The load circuit is the portion of an electrical circuit that consumes electric power due to connected electrical appliances.
Load Current
Load current refers to the total current required to power the devices connected to a power system.
Load Forecast
Load forecasting is the attempt to predict the future consumption and demands for electricity on a system.
Load Resistance
The load resistance in a solar cell is the measured resistance at the solar cell’s maximum power point.
Low Voltage Cutoff
Low voltage cutoff is the point at which a battery has fully expended its available power and to further discharge would cause harm to the battery.
Low Voltage Warning
A low voltage warning is a warning given when the voltage in an electrical system is insufficiently low to power the connected devices.
Maintenance-free Battery
A Maintenance-Free Battery is a battery that typically comes sealed for life from the manufacturer and do not require any maintenance of the electrolyte levels. Learn More Here
Maximum Power Point
When the relationship between current and voltage are plotted on a chart, the maximum power point is the point on the graph where the product of current and voltage is at is maximum. Used in solar arrays to maximize the output of power.
Maximum Power Point Tracking
The ideal load for a system that takes into account the amount of sunlight striking a solar panel, the ambient temperature, and the electrical characteristics of the load itself. Maximum Power Point Tracking, or MPPT, is the tracking and balancing of all these environmental conditions to ensure that a solar array and system are performing to their maximum potential at any given point in time.
One megawatt is defined as the power equivalent to one million watts.
A megawatt hour is the amount of electricity generated by a one megawatt electric generator over the course of one hour. One megawatt hour is equal to 1,000 kilowatt hours.
A micro-inverter is a small inverter device that is attached to each photovoltaic panel to convert DC current to AC current. Learn More Here
A micrometer is a tool for measuring very small distances with a high degree of precision.
Modified Sine Wave
A modified sine wave is a version of a true sine wave that is characterized by a distinct ‘blocky’ appearance. It still is a sine wave as it is repetitive and oscillatory in nature, but rather than a smooth oscillation like a sideways letter ‘S’, it is more square in shape. Learn More Here
In terms of electrical systems, module usually refers to a power module that physically contains various power components such as semiconductors or batteries.
Also known as polycrystalline silicon, is a type of high-purity silicon used as raw material in the production of solar cells.
N-Type Semiconductor
An n-type semiconductor is a negatively charged semiconducting material used in photovoltaic devices and created by ‘doping’ the semiconducting material with a reactive gas.
N-Type Silicon
N-type silicon is silicon that has been chemically bonded with phosphorus gas to create an electrically conductive, negatively charged, form of silicon. Learn More Here
A nanometer is one billionth of a meter. Commonly used in electrical engineering.
Net Metering
Net metering is a billing system used by power utilities where homeowners are credited for electricity they add to the grid.
Nickel Cadmium Battery
A Nickel Cadmium battery uses nickel hydroxide and cadmium hydroxide in the cathode and anode to store electrical energy as a chemical energy when fully charged.
Nominal Voltage
Nominal voltage is the stated voltage at which a device is safe to operate without damage to the system. The nominal voltage may vary from the actual voltage in a system and is often printed with additional information on the tolerances allowed without danger to the system. Learn More Here
Normal Operating Cell Temperature
Normal operating cell temperature is a standard for testing solar cells under a very specific set of environmental parameters to test real world conditions and the available wattage produced by the cell.
Off Grid
When a home or business is not connected to the power grid and, instead, generates its own power for consumption.
An ohm is the unit of electrical resistance between two points when a constant electrical potential difference measuring one volt produces a current measuring one ampere.
Open-Circuit Voltage
The open-circuit voltage is the voltage measured between two points in a device when the device is disconnected from a circuit.
Overcharge is when too much electricity is put into an electrical system or battery.
PV is shorthand for ‘Photovoltaic‘, usually referring to either the photovoltaic effect or photovoltaic panels.
In the context of solar power, a panel refers to a single device that consists of several solar cells networked together to produce photovoltaic energy. Also see Solar Panel.
Peak Demand/Load
Peak demand is the time frame during which an electrical system is expected to carry the highest demand for power and generally expressed as a time period plus unit of power.
Peak Power Current
See Maximum Power Point Tracking.
Peak Power Point
See Maximum Power Point Tracking.
Peak Power Tracking
See Maximum Power Point Tracking.
Peak Sun Hours
Peak sun hours are defined as the number of one-hour units of time where the intensity of sunlight is at least 1kW per square meter. Learn More Here
Peak Watt
Also called peak power. Peat watt is the output power achieved by a solar array under full sun.
A photocurrent is the electric current running through a photovoltaic device as a result of exposure to the sun.
Photoelectric Cell
A photoelectric cell is a device that generates an electric current from light. Also see Photovoltaic Cell.
Photoelectrochemical Cell
A photoelectrochemical cell is one of two types of devices that produce electricity through light or chemical processes. The first type of device uses a typical photovoltaic cell that generates electricity through the photovoltaic effect, while the second is a photoelectrolytic cell that converts light into electricity when it strikes a semiconductor immersed in an electrolytic solution to cause a chemical reaction.
Photons are particles that have no charge and no mass – they travel through space at the speed of light and are emitted by stars in the form of waves of electromagnetic radiation. On Earth, we can capture photons through the use of photovoltaic panels to generate electric currents that can be used to power electrical devices.
Photovoltaic refers to the generation of electrical energy through exposure to the sun which excites an electron to a higher-energy state. Learn More Here
Photovoltaic Array
A photovoltaic array is a system of one or many solar panels connected together to generate power for a home or business. Learn More Here
Photovoltaic Cell
A photovoltaic cell is a device that converts solar energy into direct current electricity for use in homes or businesses through the photovoltaic effect. Learn More Here
Photovoltaic Conversion Efficiency
Photovoltaic conversion efficiency refers to the efficiency that a photovoltaic device converts solar energy into electricity. Since sunlight is a much wider spectrum of light than most PV devices are able to use, some of that energy is lost.
Photovoltaic Device
A photovoltaic device is any device that converts solar energy into electricity via the photovoltaic effect. Learn More Here
Photovoltaic Effect
The photovoltaic effect is a natural phenomena in which an electrical current is generated by the excitation of electrons due to the addition of light to a semiconducting material. Learn More Here
Photovoltaic Generator
See Photovoltaic System.
Photovoltaic Module
A photovoltaic module is a collection of photovoltaic cells mounted together to collect sunlight for energy. Learn More Here
Photovoltaic Panel
A photovoltaic panel is one or more photovoltaic cells that are interconnected to generate electricity from light through the photovoltaic effect. Also known as a solar panel. Learn More Here
Photovoltaic System
A photovoltaic system refers to the entire system of photovoltaic devices and supporting equipment required to generate electricity from light. Learn More Here
Photovoltaic-thermal usually refers to a hybrid solar generator called a photovoltaic-thermal collector that turns sunlight into both electrical and thermal energy. For instance, a device that heats water from the sunlight while also generating electricity for use in the home.
Plug-and-Play PV System
A photovoltaic system that is designed to be operational right out of the box. Most plug and play systems are designed to be able to be installed and running within a single day.
Polycrystalline Silicon
Polycrystalline silicon is a form of high-grade silicon for use in the solar industry and refined by a chemical purification process called the Siemens process. Learn More Here
Power is a form of measurement used in electrical systems that denotes the rate per unit of time at which electricity is transferred through an electrical system. Learn More Here
Power Conditioning
In a solar power system, the power conditioning unit is actually a set of devices including a charge controller, inverter, and a grid charger that work in tandem to provide usable electricity for a home or business.
Power Conditioning Equipment
A device that improves the quality of power that is delivered to devices connected to the system. For instance, a power inverter.
Power Conversion Efficiency
Power conversion efficiency refers to a solar panel’s efficiency at converting solar energy into usable power. Power conversion efficiency is measured as a ratio of power output to power input.
Power Density
Power density refers to the total amount of power per unit of volume that a device holds. Learn More Here
Power Factor
Power factor refers to the ratio of real electrical power absorbed by a system to the apparent power that is available in a circuit. Power factor is expressed at a unit-less number between -1 and 1.
Primary Battery
A primary battery is a type of battery that cannot be recharged and is designed to be thrown away following use.
A pyranometer is a device that measures solar irradiance from a full hemispherical field of view on a flat surface.
An instrument for measuring the total intensity of solar radiation at a given point.
A quad is one quadrillion BTUs (a one with fifteen zeros after it).
Ramp Rate
The unit of energy that denotes the flow of electrons in a system per hour.
Rated Power
Rated power is the power output of a device under its ideal operating conditions. Learn More Here
A regulator, or voltage regulator, is a device that helps to maintain the voltage of a power source within particular specifications in order to protect the electrical devices attached to the system.
Renewable Energy
Renewable energy refers to any electricity produced from a natural source that is constantly replenished by nature. Some examples of renewable energy include wind, solar, hydroelectric, or geothermic energies.
Reserve Capacity
Reserve capacity is the time that a battery or other storage device can supply power to a system once the system is no longer being charged. Learn More Here
Resistance is the measure of how difficult it is for a current to flow through an electrical circuit. Resistance is measured in terms of Ohms.
Sealed Battery
See Maintenance-Free Battery.
Seasonal Depth of Discharge
Seasonal depth of discharge is a metric used when planning a solar array that takes into account that during parts of the year there is poor solar insolation and the battery may not fully recharge during the daylight hours. This planning assumes that over a 30-90 day window, the battery may become fully discharged before there is a net positive charge again.
Secondary Battery
A secondary battery is a type of battery or storage cell that can be recharged after use many times over. As opposed to a primary battery which can only be used once.
Self-discharge refers to the phenomenon in which a battery loses stored charge due to its own internal chemical reactions rather than from being connected to an electrical device.
Semiconductors are a special kind of crystalline materials that sit between conductors and insulators in the scale of conductivity. They are particularly important for the manufacture of solar panels and computer chips.
As referring to a solid, possessing a degree of crystalline character. In the solar industry, this is usually referring to the solar panels.
Short-Circuit Current
The short circuit current of a solar cell is the current that remains in the solar cell when the voltage is at zero.
Silicon is element number 14. It is a nonmetal that also happens to have powerful semiconducting properties and one of the most important elements in the world for production of electronic circuits and solar panels. In its pure form, silicon is shiny and dark grey in color.
Sine Wave
A sine wave is a geometric wave that moves up and down at a regular interval, and is defined by the function y = sin x. Learn More Here
Sine Wave Inverter
A sine wave inverter is a device that converts direct current power to a form of alternating current power that can be used by modern appliances by modifying the waveform shape of the current. Learn More Here
Single-Crystal Material
A single-crystal material is a material consisting of a single, unbroken crystal lattice with no grain boundaries. As pertaining to electrical conductors a single crystal would possibly provide the means to achieve a perfect metallic conductor.
Smart Grid
A smart grid refers to the network of infrastructure that connects power producers and consumers, but unlike the normal grid a smart grid has two-way electricity flow and is able to react to changes in demand throughout the grid and even some self-healing capabilities.
Soft Costs
All expenses not accounted for when budgeting a particular task. Most commonly used in regard to construction.
Solar Battery
Formally, a solar battery is defined as a networked grid of photovoltaic cells. Practically, a solar battery refers to a storage device used to store power generated by the sun. Learn More Here
Solar Cell
A solar cell is the colloquial term for a photovoltaic cell which converts solar energy into direct current electricity for use in homes or businesses through the photovoltaic effect. Learn More Here
Solar Constant
The solar constant is the constant rate at which solar radiation hits the surface of the earth, which is accepted to be approximately 1,388 watts per square meter. Learn More Here
Solar Dealer
A solar dealer is a company that sells solar equipment and infrastructure for installation on homes and businesses. Learn More Here
Solar Energy
Solar energy is the combination of all forms of energy, radiant light, heat, and radiation, that are emitted from the sun and can be harnessed by a variety of solar devices to power homes and businesses around the world. Learn More Here
Solar Installer
A solar installer is someone who installs solar panels on structures for the purpose of converting sunlight into photovoltaic energy. Learn More Here
Solar Irradiance
Solar irradiance is the total amount of solar radiation measured over a specific area, typically noted as watts per one square meter. Learn More Here
Solar Monitoring
Solar monitoring is an ambiguous term to refer to a range of activities that include monitoring of photovoltaic systems and solar activity. Most commonly, solar monitoring refers to the suite of systems that observe and report on photovoltaic systems. Learn More Here
Solar Noon
Solar noon is the moment that the sun reaches its highest point in the sky at any particular location. Learn More Here
Solar Panel
Solar panel is the colloquial term for a photovoltaic module that uses sunlight to harness solar energy. Learn More Here
Solar Panel Cleaning
Solar panels need regular cleaning in order to maintain optimum power output. Solar panel cleaning refers to this act of regular maintenance.
Solar Panel Contractor
Also known as a solar installer, a solar panel contractor is specifically trained to work with solar panels and associated systems involved in converting solar power into electricity. Learn More Here
Solar Panel Efficiency
Solar panel efficiency is the measurement of a solar panel’s ability to convert sunlight into usable electricity.
Solar Power Plant
A solar power plant is a system that is designed to collect solar radiation and convert it into either electricity or heat for use by the end consumer. Rather than referring to a specific component, the term ‘solar power plant’ refers to the entire installation and system that works together to collect and refine solar energy for home or business use.
Solar Renewable Energy Credit
A solar renewable energy credit allows homeowners to sell their excess energy generated back to the utility company for cash compensation. Learn More Here
Solar Shingles
Solar shingles are small photovoltaic modules designed to look and function similar to a standard asphalt or slate roofing material while also producing photovoltaic energy. Learn More Here
Solar Spectrum
The solar spectrum is the complete spectrum from UV to infrared wavelengths of light that is emitted from the sun. Only a small portion of the solar spectrum is visible to the human eye.
Solar-Grade Silicon
Solar grade silicon is a form of high-purity silicon (99.9999% pure) that is produced exclusively for the solar industry and does not typically include semiconductor-grade silicon. Learn More Here
Solar-plus-storage refers to a complete system of devices that generate, store, and control the usage of power generated by the light of the sun through the photovoltaic effect. Learn More Here
Square Wave
Square wave refers to the shape of a particular waveform that looks very square-like in appearance. Electricity that has a square wave is not suited for most appliances and must be converted to another type that is more suitable.
Square Wave Inverter
A type of power inverter that converts direct current to a form of alternating current electricity. Due to the square wave shape, this type of electrical power is not appropriate for many devices.
Stand-Alone System
A stand-alone system is a photovoltaic system designed to be fully self-sufficient, charging batteries during the day for use during the night. A stand-alone system is not designed to be grid-connected.
Standby Current
The electric current that is drawn from a system by electrical devices when they are powered off.
Starved Electrolyte Cell
A starved electrolyte cell is a battery cell that has little to no electrolyte remaining. This means that the battery will not be able to react with the active materials it contains to hold or discharge an electrical current.
State of charge refers to the current level of charge in a battery as expressed relative to its total capacity. For example, 0% means the battery is fully drained, while 100% means that the battery’s state-of-charge is fully charged.
Storage Battery
A storage battery is a particular kind of battery that it used to store energy generated from another source. Often used in conjunction with a solar electricity generation system to power appliances when the sun is not shining. Learn More Here
Superconductivity is a special property found in some materials in which electrical resistance is completely eliminated and magnetic flux fields are expelled from the material, allowing an electrical current to pass through it with almost zero loss.
Surge Capacity
The surge capacity is the ability for a device such as an inverter to handle the momentary high currents required when, for instance, a motor is started.
System Availability
System availability is a metric that refers to the likelihood a system is available for use (as opposed to failed or undergoing maintenance) at any given point in time. This is sometimes also known as equipment availability or asset availability.
System Operating Voltage
The voltage that a system is designed for and to which many of the operating characteristics of the system may be designed.
Temperature Factor
Temperature factor is the difference between the interior temperature of an object and the air surrounding it.
Thick-Crystalline Materials
A thick-crystalline material, as used in the solar industry, is a semiconductor material typically measuring between 200-400 microns thick.
Thin Film Photovoltaic Module
A thin film photovoltaic module is a solar module made with thin film technology rather than traditional crystalline silicon panels. Thin film modules are typically much lighter and cheaper to produce than their traditional counterparts, however their efficiency is often lower. Learn More Here
Tilt Angle
Also known as the elevation angle, the tilt angle is the angle above horizontal at which a solar panel is mounted. Learn More Here
Total AC Load Demand
The total AC load demand is the sum of all electrical device requirements on the AC portion of a solar-connected electrical system.
A transformer is an electrical device that either increases or decreases the voltage of an alternating current for either transmission or consumption by an end user.
Trickle Charge
Trickle charge refers to a device that slowly charges a battery using a very small current equal to its discharge rate, thus keeping the battery fully charged.
Ultraviolet is a particular band of wavelengths in the light spectrum between 40-400 nanometers. Ultraviolet light is just light the light we see, but sits just outside of human’s visible range. Some solar arrays are able to take advantage of the ultraviolet spectrum.
Valence Band
The valence band is the outermost band of electrons in an atom of any material. When electrons are excited, the valence band electrons can move to the conduction band.
Vented Cell
In vented cell batteries, the battery lacks the ability to recombine gasses produced during normal operations and must be vented in order to prevent explosion. Most commonly used in nickel-cadmium batteries.
See Voltage.
Voltage is one type of measurement used in electrical systems that denotes the force needed to move an electrical current through a system. Learn More Here
Voltage Protection
Voltage protection is a device that protects an electrical circuit against being used when there is not enough voltage in the system.
Voltage Regulation
Voltage regulation is the measure of difference in voltage between two points in a system. Usually, this refers to a device that actively limits voltage for the purpose of protecting the electrical devices attached to the system.
Voltage at Maximum Power
The voltage at maximum power, or VMPP, is the voltage at which power output is at its greatest.
One watt is equal to one joule per second.
A waveform is a graph or curve that shows the shape of a wave at a given point in time. This shape is a function of time, magnitude, and displacement in time. When used in electronics a waveform usually refers to a periodically varying voltage or electrical current that, when graphed, would look like a curving wave.
X-rays are a band of electromagnetic radiation that are between ultraviolet light and gamma rays on the wavelength spectrum. Not visible to the human eye and not typically used in solar applications.
A year is 365 days on Earth.
Zenith Angle
The zenith angle is the angle between the sun’s rays and vertical at any given point on Earth. Learn More Here