The Big Solar Energy Glossary: Top Terms & Acronyms You Need to Know

Solar Energy Terms

All terms and acronyms are defined in the context of solar energy.

• Aging

  Aging refers to how solar panels degrade and gradually become less efficient over time. Just like anything that gets used a lot, the materials in the panel will eventually break down and become less effective over time. The solar panel aging process can be slowed down through regular maintenance.

• Alternating Current

  Alternating current (AC) is the standard type of electricity used in American homes and buildings, and different from the direct current (DC) that’s produced by solar panels. An inverter is used to convert the DC electricity produced by solar panels into AC electricity we can use to power our property.

• Alternative Energy

  Alternative Energy refers to sources of energy that differ from traditional fossil fuel sources like coal and oil. The use of alternative energy sources — which include solar power — can help reduce greenhouse gas emissions, reduce some types of air pollution and protect the environment.

• Amp

  An Ampere, or Amp (A) is a unit of measurement that tells us how much current is flowing through a conductor when a voltage is present. The more amps a solar panel produces, the more electricity it generates.

• Angle of Incidence

  The angle of incidence is the angle at which sunlight hits a solar panel. This plays a role in ensuring panels are at the right angle for direct sunshine exposure, which then maximizes the system’s efficiency and helps generate the most energy possible.

• Anti-Reflection Coating

  Anti-reflection coating is put on the surface of solar panels to help reduce the amount of reflection and glare and increase the amount of sunlight that gets absorbed. This can help make the panel more efficient and generate more electricity.

• Array

  A solar array — also known as a photovoltaic (PV) array — is a group of connected solar panels that work together to produce more electricity than a single solar panel can. It's a way to harness the sun's energy, convert it to electricity for and use it to power our homes and buildings.

• Authority Having Jurisdiction

  The Authority Having Jurisdiction (AHJ) is the person or group of people in a city’s Building Department who are responsible for solar permitting and inspections to ensure installations meet the requirements of local laws and building codes. They have the power to enforce regulations and require changes, if necessary.

• Availability

  Availability refers to when a solar energy system can generate electricity. Solar energy availability depends on factors like weather conditions, placement and geographic location of the panels.

• Axial Tilt

  Axial tilt refers to the tilt of the Earth’s axis relative to the sun, affecting the amount of sunlight that solar panels receive. In areas near the equator where the Earth's tilt has less effect, solar panels can get more consistent amounts of sunlight throughout the year. In areas further from the equator, the amount of sunlight solar panels receive can vary between seasons.

• Azimuth

  Azimuth is the term used to describe which angle or direction a solar panel is facing. Solar panels produce the most electricity when they are directly facing the sun. Adjusting a panel’s azimuth accordingly helps maximize the power output of a solar energy system.

• Backfeeding

  Backfeeding happens when electricity flows backward through a solar energy system, instead of forward like it’s supposed to. This can happen if there’s a power outage in the area and a home or building has solar panels with battery backup. To prevent this, a solar battery system uses a backfeed protection mechanism that stops electricity from flowing out of the battery and into the grid.

• Balance of System

  Balance of System (BOS) refers to all parts and costs of a solar energy system other than the solar panels themselves. This includes components like the conduit, wiring, mounting structures and safety equipment — and services like design, site preparation, operation and maintenance. BOS ensures the power generated from a solar system is safe, efficient and usable in a home or building.

• Base Load

  Base load is the minimum amount of power to meet the energy demands of a home or building, regardless of source. To ensure a consistent and reliable source of power that meets the base load, battery backups may be used to store excess energy generated during periods of high solar production, for use during periods of low production.

• Battery Energy Storage System

  A battery energy storage system (BESS) is a rechargeable device that stores excess power generated by solar panels for use when the sun isn’t shining, during times of peak demand, to avoid demand charge pricing or in the event of a power outage. Battery energy storage systems come in many different sizes and capacities and can be used for everything from powering a single home or business, to creating a microgrid that provides backup energy for an entire neighborhood. Battery energy storage systems are an important part of creating a sustainable and reliable energy system for the future.

• Battery Management System

  A battery management system (BMS) acts like the brain for a solar energy storage system, ensuring the battery stays safe and performs at its best. The BMS can monitor important things like the battery’s temperature, how much energy is being used and how much is left. It also makes sure the battery isn’t overcharged or discharged too much, which can damage the system.

• Bidirectional Meter

  A bidirectional meter is a special type of meter that measures the electricity flowing to and from a home or building. It keeps track of how much electricity is consumed and how much is generated from solar panels — that way, a utility provider can accurately calculate and provide credits to the system owner for any excess electricity generated.

• Blocking Diode

  A blocking diode is a tiny device that acts like a one-way gate for electricity produced from a solar panel. It allows power to flow in one direction — out of the solar panel and into a battery backup system, for example — and blocks it from flowing in the opposite direction. Using a blocking diode ensures that solar-generated electricity can power a home or business and store any excess electricity in a battery for later use.

• Busbar

  In a solar energy system, the busbar — or bus — is a connection point that carries direct current (DC) or alternating current (AC) electricity from solar panels to the inverter, which converts it into useable power for use in a home or business. The bus also carries electricity from the inverter to an electrical panel, battery energy storage system or power grid.

• Canopy

  A solar canopy incorporates solar panels into overhead structures in places like parking lots, walkways or recreational areas. Solar canopies can provide shade from the elements, while simultaneously producing clean and renewable energy to power nearby homes, buildings, lighting systems or EV charging stations.

• Capacity Factor

  Capacity factor measures the amount of energy a solar panel actually produces compared to the amount of energy it could produce if it worked perfectly all the time. For example, if a solar panel produces 50 watts of energy for one hour, but could produce 100 watts when working perfectly, then the capacity factor is 50%. The higher the capacity factor, the better the solar panel is working.

• Carbon Dioxide

  Carbon dioxide (CO2) is a greenhouse gas that’s produced when burning fossil fuels like coal, oil and natural gas. Since solar is a clean and renewable source of energy that does not emit carbon dioxide or other harmful pollutants, its use reduces reliance on fossil fuels and helps lower the amount of CO2 emissions into the atmosphere.

• Cell

  A solar cell is a tiny electronic device that can turn light from the sun into electricity. It’s typically made of a special material called silicon, which has unique properties that make it good at absorbing sunlight and converting it into energy. When multiple cells are grouped together, they form a solar panel — the more cells in a panel, the more electricity it can generate.

• Charge

  A charge refers to the flow of electrical energy through a solar cell or battery. When the sun shines on a solar panel cell, the photons from the sun excite electrons in the PV panels, which result in an electric current, creating electricity. In a battery, there is a build-up of electric charge or stored energy, which can then be used to power devices on demand.

• Charge Controller

  A charge controller is used in battery storage systems to help manage and regulate the energy produced by solar panels. If, for example, the battery is getting too much charge, the controller will reduce the amount of electricity going into it — if the battery needs more charge, the controller increases the flow of electricity. This helps keep the battery in good condition and ensures the energy system is running efficiently.

• Circuit

  A circuit is like a path for the flow of electricity. Circuits allow for the connection of panels to make a larger solar energy system. A circuit has several parts — including a power source (like a solar panel or battery), wires to carry the electricity and load, or devices that use electricity (like a lightbulb or household appliance). When the circuit is complete and everything is connected properly, electricity can flow through the wires and power the devices connected to it.

• Conversion Efficiency

  Conversion efficiency measures how well solar panels can convert sunlight into electricity. For example, if you have a panel that’s receiving 100 units of sunlight, but it’s only able to convert 50 of them into electricity, its conversion efficiency is 50%, which means half of the sun’s energy that hits the panel is not being used to make electricity. PV conversion efficiency has improved substantially over the years, but still only around 20 – 24%.

• Converter

  A converter, or inverter, is a device that converts the direct current (DC) electricity produced by solar panels into the alternating current (AC) form so it can be used to power appliances. There are different kinds of converters — like microinverters, which are small and installed on individual solar panels, and string inverters, which are larger and installed in a central location for a group of solar panels.

• Coupling

  Coupling is how different components of a solar power system are connected and work together to efficiently and effectively produce electricity. The relationship between solar panels and inverters — and, when applicable, solar batteries — are two examples of coupling. Solar and storage can either be AC coupled or DC coupled depending on hardware architecture.

• Cycle

  The solar energy cycle refers to the process of capturing and converting sunlight into electricity. First, sunlight is captured by solar panels, whose photovoltaic cells convert it into direct current (DC) electricity. Next, the DC electricity flows to an inverter, which converts it into alternating current (AC) electricity. Finally, the AC is used to power homes and businesses.

• Dealer

  A solar dealer is a person or company that specializes in selling, distributing and/or installing solar energy products, services and systems to customers. They are key players in expanding the adoption of solar power by offering expert guidance and local knowledge throughout a home or business’ solar journey.

• Degradation

  Degradation refers to the gradual decrease in the performance or efficiency of solar panels or a battery energy storage system over time. There is cell degradation — which happens at the solar cell level — and module degradation, which occurs to the overall decrease in performance of a solar panel. Degradation in a solar energy system can happen due to various factors, such as natural aging and exposure to weather conditions. Modern solar equipment is designed to last a long time and retain a high percentage of their original efficiency, and degradation can be minimized with regular maintenance and care.

• Demand Charge

  A demand charge is an increased rate paid for electricity used during a designated peak demand period. If a residence or building has solar panels installed, demand charges can be reduced through proper timing and the use of a battery energy storage system.

• Department of Energy

  The Department of Energy (DOE) is a U.S. government agency that’s responsible for advancing energy technology and promoting renewable energy sources like solar power. It plays a key role in funding research, developing policies and supporting initiatives to drive the adoption and growth of solar energy in the country.

• Depth of Discharge

  Depth of discharge (DoD) refers to how much energy is cycled into and out of a solar battery. When the battery is fully depleted, it’s at 100% depth of discharge, which means it has no usable energy. As electricity is used from the battery, the depth of discharge increases. Monitoring and managing the depth of discharge helps optimize a solar battery’s performance and longevity, and ensures stored energy is used efficiently without damaging the system.

• Diffuse Radiation

  Diffuse radiation is soft sunlight that’s scattered and spread out in different directions — rather than a strong, direct beam of sunlight — before reaching the Earth’s surface. This commonly occurs when sunlight passes through clouds or haze. Solar panels can still capture and convert diffuse radiation into electricity, although less efficiently than they would with direct sunlight.

• Direct Current

  Direct current (DC) is the type of electrical current that’s produced by solar panels when they capture sunlight — it’s the first step in generating electricity from the sun. Direct Current (DC) is also the type of energy stored in a battery. In most cases, the direct current needs to be converted into alternating current (AC) to be used in homes and businesses, which is done using an inverter.

• Disconnect Switch

  A disconnect switch is an important safety device used in solar energy systems to control the flow of electricity from solar panels. During maintenance or in case of an emergency, the disconnect switch can be turned on to break the connection between the panels and the rest of the electrical system — making sure no electricity flows through.

• Distributed Generation

  Distributed generation, also known as decentralized energy, refers to the generation of electricity from many small-scale power sources — often from renewable energy sources like solar — located close to the point of use, rather than a centralized source like a power plant. Distributed generation allows homes, businesses and public buildings to produce clean and renewable energy right where it’s used, which increases reliability and reduces vulnerability to disruptions from wildfires, public safety power shutoffs and more.

• Downtime

  Downtime is the period when a solar energy system is not generating electricity. When solar panels don’t receive enough sunlight to generate electricity — like at night — or have a malfunctioning component, it results in downtime. Solar energy systems are designed to work efficiently and minimize downtime as much as possible. They are built to withstand different weather conditions and have safeguards in place to ensure smooth operation. During downtime, alternative sources of energy — like the grid or a solar battery — may be used until the system is running again.

• Dual-Axis Tracking

  Dual-axis tracking is a type of solar mounting system that allows solar panels to move and adjust their position to face the sun directly throughout the day. The system has two axes — one that moves the solar panels up and down, and another that rotates them from side to side. By following the sun’s movements, these systems can capture more sunlight and generate more electricity.

• Due Diligence

  Due diligence is the process of carefully examining and investigating all aspects of a solar energy project. It involves researching and gathering information about the project’s feasibility, potential issues, financial viability and compliance with regulations. Factors analyzed during due diligence include site location, resource availability, engineering design, equipment quality, financial projections and government permits. Conducting due diligence helps people make more informed decisions about their solar project, helps avoid potential problems and ensures long-term success.

• Efficiency

  Efficiency measures how well a solar energy system can convert sunlight into usable electricity. It’s an important factor, particularly where space is limited, because higher efficiency solar panels can generate more energy from the same amount of sunlight versus lower efficiency panels.

• Electric Vehicle

  An electric vehicle (EV) is a type of vehicle that runs on electricity instead of gasoline or diesel, using a rechargeable battery to store the electricity it needs to run. By powering an EV battery with clean energy sources like solar, it helps reduce dependence on fossil fuels, lower greenhouse gas emissions and make a more positive impact on the environment.

• Electrode

  An electrode is a component of a solar panel cell that works with the semiconductor to collect electron particles and carry them away to generate electricity. It consists of a positive side, or anode, and a negative side, or cathode.

• Emissions

  Emissions refer to the release of destructive gases and pollutants into the environment. When traditional energy sources like fossil fuels are used to generate electricity, they produce harmful emissions, like carbon dioxide (CO2), as a byproduct. Solar, on the other hand, is a clean and renewable source of energy that does not release any harmful emissions during operation. Using solar energy can combat climate change by reducing the number of harmful emissions released into the atmosphere.

• Energy

  Energy (kWh) is a measure of power over time.

• Energy Audit

  An energy audit is a survey that helps a home or business understand how much energy it’s using, where it’s being wasted and improvements that can be made to save energy and money. An energy audit can be used to determine whether installing a solar energy system would be a good fit, and how much money might be saved on utility bills by switching to solar.

• Energy Information Administration

  The Energy Information Administration (EIA) is an independent statistical agency within the U.S. Department of Energy. It was established in 1977 to provide objective, timely and relevant information to the public and policymakers about the energy sector — including coal, electricity, natural gas, petroleum and renewable energy like solar.

• Energy Payback

  Energy payback is the time it takes for a solar energy system to produce enough electricity to compensate for the energy used during its manufacturing and installation. Once the system surpasses this point, it has officially offset the energy it took to create it, and from there on starts generating sustainable energy. It takes just a few years of operation to reach the energy payback “break-even” point.

• Engineering, Procurement & Construction

  Engineering, Procurement & Construction (EPC) is the team or business used to bring a solar energy system to life. Engineering is where experts design the system, determine the best spots to install the solar panels and figure out how they are connected to get maximum output. Procurement is where the necessary materials for the project are gathered, and construction is where the team installs the system and ensures everything is working properly.

• Environmental Protection Agency

  The Environmental Protection Agency (EPA) is a U.S. government agency that plays a role in setting guidelines and regulations to protect the environment and promote clean energy practices. They work to ensure solar energy projects and systems comply with environmental standards and regulations, and also provide resources and information on solar energy efficiency and environmental benefits.

• Equalization

  Equalization is the process used to balance the charge in a battery energy storage system. Over time, solar batteries can become imbalanced, which affects the rate of recharge and discharge. Equalization addresses this by applying a higher voltage for a specific period, which helps redistribute the charge to equal levels. Performing equalization regularly on a solar battery helps maintain its long-term health and performance.

• Export Meter

  An export meter is a device that keeps track of how much excess electricity your solar panels send back to the power grid. This is important for grid services, because the utility uses this information to calculate how much credit a home or business should receive for the shared energy. The export meter is typically installed alongside a regular electric meter.

• Façade Integration

  Façade integration is the process of incorporating solar panels into the outer walls of a home or building, instead of or in addition to installing them on the roof or ground. Also referred to as building-integrated photovoltaics (BIPV), these special solar panels are typically designed to blend in with the building’s architecture, and can be installed in different shapes, sizes and colors.

• Feed-in-Tariff

  A feed-in-tariff is a renewable energy policy in which a government agency or utility company offers payment to the owner of a solar energy system for the total amount of electricity they produce and send to the grid.

• Fill Factor

  A fill factor measures how efficiently a solar cell or panel can convert sunlight into electricity. A high fill factor means it does a good job of converting sunlight, with minimal energy loss. A low fill factor means some or all the sunlight’s energy is not being effectively and efficiently converted.

• Fixed Tilt

  Fixed tilt is the position or angle at which a solar panel is permanently set or fixed. The panel is set at an angle to maximize the amount of sunlight it captures throughout the day, based on specific location and average path of sun in the area.

• Float Charge

  A float charge is a charging mode used when a solar battery is fully charged. It provides just enough power to keep it full without wasting energy or overcharging it, which can potentially damage the system.

• Floatovoltaics

  Floatovoltaics is a type of solar power that uses floating solar panels on bodies of water. Made of the same materials as regular solar panels, the floating platforms are anchored to the bottom of the water with cables or chains.

• Forced Outage

  A forced outage happens when a traditional power plant or solar energy system unexpectedly stops working — whether due to a problem with the system or facility itself, or bad weather. When a forced outage happens at a residence that has solar panels and a solar battery installed, it can become an electrical island and limited power may be supplied from the battery.

• Fossil Fuel

  Fossil fuel refers to a type of fuel that comes from non-renewable sources like coal, oil and natural gas — all formed over a very long period under the Earth’s surface. Fossil fuels have traditionally been used to generate energy, but their burning releases greenhouse gases, which are harmful to the environment and contribute to climate change. Their use is decreasing in lieu of cleaner sources of energy, like solar power.

• Frequency Regulation

  Frequency regulation manages the supply and demand of electricity. When supply is higher than demand, frequency peaks. It dips when demand is higher than supply. Devices called frequency regulators monitor and adjust frequency accordingly to maintain stability and ensure our devices and electrical systems — including solar — work properly and meet the demand.

• Full Sun

  Full sun is the optimal amount of sunlight that reaches the Earth’s surface without any obstructions, like clouds or haze. This is when the sun is shining at its brightest and providing panels with the maximum level of solar energy.

• Generator

  A generator is a device that provides backup electricity during a power outage. It’s typically fueled by gasoline, diesel or natural gas. When the regular power supply is interrupted, the backup generator starts running and provides temporary power to keep essential devices and appliances in a home or building running until grid power is restored.

• Gigawatt

  A gigawatt (GW) is a unit of power that’s equal to one billion watts, one million kilowatts (kW) or one thousand megawatts (MW). It represents a substantial amount of power generated by solar energy installations, contributing to the clean and sustainable generation of electricity.

• Global Irradiance

  Global irradiance is the total amount of sunlight or solar radiation — including direct sunlight and scattered light — that reaches a specific area on the Earth’s surface. Using factors like angle of the sun, weather conditions and time of year, global irradiance helps solar designers determine how many panels are needed and how much electricity they can generate in a specific area.

• Global Warming

  Global warming refers to the long-term increase in Earth’s average temperature due to the accumulation of greenhouse gases in the atmosphere. It’s caused in part by the burning of fossil fuels like coal, oil and natural gas. Renewable energy sources like solar are a viable solution in mitigating global warming, since they can generate clean power without emitting harmful greenhouse gases.

• Greenhouse Gases

  Greenhouse gases are gases present in the Earth’s atmosphere, like carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and more. Acting like a blanket for the planet, they trap some of the sun’s heat and help keep our planet warm, creating the greenhouse effect. Too much greenhouse gas in the environment— brought about in part by the burning of fossil fuels to produce energy — can trap more heat than desired, leading to global warming and climate change. Using solar energy instead of fossil fuels can help reduce the amount of greenhouse gases being emitted.

• Green Pricing

  Green pricing refers to a program offered by utilities that allow customers to support renewable energy sources, like solar power, by paying a premium on their electricity bills. The additional funds collected through green pricing programs are used to invest in renewable energy projects, like the installation and operation of solar panels.

• Grid

  The grid is a large network of power lines that’s responsible for delivering electricity from power plants to homes, businesses and cities. Most solar energy systems installed in the United States are tied to the grid — this means when panels produce more electricity than a home or building is using, the excess can be sent back to the grid.

• Grid Services

  Grid services are the valuable contributions that solar power can provide to the electrical grid — including energy supply, load balancing, frequency regulation and overall grid stability. An increasing number of power companies are willing to compensate the owners of solar energy systems for the energy they provide back to the grid, allowing them to enroll in grid services programs to realize this value.

• Gross Metering

  Gross metering is the process by which all the electricity generated by a solar energy system is sent to the electrical grid. In this setup, the system is connected directly to the grid. This differs from its net metering counterpart, which only sends excess solar energy to the grid, and is connected to the home or building using it.

• Ground Mount Solar

  Ground mount solar is the process of installing solar panels on the ground, instead of on a roof or canopy. Set up on racks or structures securely anchored to the land, ground mounted solar panels are often strategically positioned to maximize solar exposure throughout the day. They are often used in large-scale solar installations such as solar farms, commercial solar or community solar projects.

• Harnessing

  Harnessing is the process of capturing the sun’s energy and converting it into usable forms of power through technologies like solar energy systems. Harnessing can be utilized in residential, commercial and industrial settings to power homes, buildings and entire communities.

• Heat Pump

  A heat pump is a device that transfers heat from one place, most commonly the outside air or ground, to another, typically a home or building. Heat pumps can be used in conjunction with solar energy to create a more efficient and sustainable heating and cooling system. Heat pumps are highly efficient, reliable and can be used in a variety of climates. Heat pumps can also function as water heaters.

• Heating, Ventilation & Air Conditioning

  Heating, ventilation & air conditioning (HVAC) is the system that controls the indoor climate and temperature of a home or building. Solar energy can be used to power an HVAC system to create a more sustainable and energy-efficient indoor environment.

• Heliostat

  A heliostat is a device used to track the movement of the sun and reflect its rays onto a specific target, with the primary purpose of redirecting sunlight to a desired location, such as a solar power tower or central receiver in a solar power plant. Heliostats typically automatically adjust to track daily or seasonal changes in the sun’s position.

• Hub

  The hub, or Microgrid Interconnect Device (MID), is the central point of a solar energy system responsible for distributing and managing the flow of energy. It manages power sources, storage and load to ensure safe and reliable operation of an energy system.

• Hybrid Electric Vehicle

  A hybrid electric vehicle (HEV) is a type of fuel-efficient vehicle combining two power sources to propel it — an internal combustion engine, typically fueled by gasoline, and an electric motor powered by a battery. Some HEVs can incorporate solar energy to assist in charging the battery.

• Hybrid System

  A hybrid system refers to a power generation system combining multiple sources of energy to provide electricity. Typically, it involves integrating solar power with another renewable energy source — like a backup generator or battery — or conventional energy source, like the grid or natural gas. The combination allows for a more consistent power output, ensuring a stable energy supply.

• Incident Angle

  An incident angle is the angle at which sunlight strikes a surface, such as a solar panel. It affects the amount of energy that can be captured and converted into electricity. A lower incident angle allows for more efficient energy capture, while a higher incident angle reduces absorption. It’s important to find the best angle to harness maximum energy from the sun.

• Independent Power Producer

  An independent power producer (IPP) is an entity that generates electricity from a solar energy system and sells it to utilities or consumers. They typically operate independent solar power plants, solar farms or large-scale installations and play an important role in increasing the supply, accessibility and affordability of renewable energy.

• Independent System Operator

  An independent system operator (ISO) is an organization that manages and operates the grid to ensure a reliable supply of electricity. They also oversee the integration and coordination of solar power generation into the grid — ensuring it’s properly managed and balanced with other sources of electricity to meet the energy needs of consumers.

• Intensity

  Intensity refers to the amount of sunlight or solar radiation that reaches a particular surface. It represents the strength or concentration of solar energy and is often measured in units, like watts per square meter (W/m²). Higher intensity means more sunlight is available, which can result in increased power generation from solar panels.

• Interconnection

  Interconnection is the process of connecting a solar energy system to the electrical grid. It allows the solar-generated electricity to be used in homes or businesses and allows any excess electricity to be sent back to the grid.

• Inverter

  An inverter is a device that converts the direct current (DC) electricity produced by solar panels into alternating current (AC) electricity, which is used to power homes, businesses and appliances.

• Investment Tax Credit

  The Investment Tax Credit (ITC) is a U.S. government incentive that provides a tax credit to individuals or businesses that invest in solar energy systems — allowing them to deduct at least 30% of the cost of their solar panels, battery storage or other renewable energy properties from their federal taxes through 2032. Its purpose is to help reduce the overall cost of solar energy systems and encourage more people to go solar.

• Investor-Owned Utility

  An investor-owned utility (IOU) is a type of utility company that’s privately owned by investors — rather than a public entity — and responsible for generating, transmitting and distributing electricity to customers. IOUs may play a role in purchasing solar power from energy producers and integrating it into their electrical grid.

• Irradiation

  Irradiation is a measure of the intensity of sunlight or solar radiation received at a specific location. High irradiation levels indicate areas with abundant solar energy potential, making them ideal for solar power generation.

• Islanding

  Islanding is the process by which a solar energy system — when paired with a solar battery — continues to generate electricity, even during a power outage when the grid is down. The system becomes like an "island" that operates independently from the main power grid, ensuring essential power is still available.

• Joule

  A joule is a unit of measurement that helps us understand how much energy is being produced or used. The amount of electricity produced by solar panels is sometimes measured in joules.

• Junction Box

  A junction box is a small, box-like enclosure responsible for connecting and protecting the electrical connections in a solar panel. It provides a safe and secure environment to ensure the connections are shielded from environmental factors and accidental contact. A junction box may also include diodes, connectors or terminals to improve efficiency and facilitate connection between multiple panels.

• Kilowatt

  A kilowatt (kW) is a unit of power used to measure how much electricity a solar energy system can generate, or how much electricity is being consumed. It is equal to 1,000 watts.

• Kilowatt Hour

  A kilowatt hour (kWh) is a unit of measurement describing how much electricity is generated by a solar energy system per hour. This helps people understand how much energy their home or business is using or producing in any given day.

• Kickstand

  A kickstand is a device that helps keep solar panels upright and in place. Typically attached to the back of a panel, it can be adjusted to different angles to ensure optimal sunlight capture.

• Kyoto Protocol

  The Kyoto Protocol is a 1997 international agreement made to address the issue of climate change. It sets targets for participating countries to limit their emissions of greenhouse gases being released into the atmosphere — promoting cleaner energy sources like solar power.

• Latitude

  Latitude tells you how north or south a place is from the Earth’s equator. The position of the sun in the sky and the amount of sunlight can vary depending on latitude. Places closer to the equator — which have a lower latitude — tend to receive more direct sunlight throughout the year because they’re closer to the sun’s rays. Higher latitude locations receive sunlight at a more slanted angle, spread out over a larger area. Latitude determines the overall effectiveness of solar energy in different locations around the world.

• Lease

  A solar lease is an agreement where a homeowner or business can rent or lease solar panels from a solar energy company. The panels are installed on the property and the customer benefits from the electricity they generate. The lease typically involves a fixed monthly payment based on the amount of electricity produced. This agreement can be an alternative to purchasing solar outright and allows for access to its benefits without the upfront cost.

• Levelized Cost of Energy

  Levelized Cost of Energy (LCOE) is a way of measuring how much it costs to generate electricity from a solar energy system over its lifetime. It considers the initial cost of setting up the system, and the costs of maintaining it, operating it and replacing parts over its life. It also calculates how much electricity the system will produce over that time, dividing the total cost by the total amount of electricity generated. LCOE helps people decide if solar is a long-term, cost-effective option compared to other sources of electricity.

• Level 2 Charger

  A Level 2 charger is a type of electric vehicle (EV) charger that operates at a higher power level than a standard household outlet. It can charge an EV faster and is often used in conjunction with solar panels to take advantage of renewable energy for charging the vehicle.

• Level 3 Charger

  A Level 3 charger is a high-power EV charging station, also known as a DC fast charger. It can provide a significantly faster charging speed than its Level 1 and 2 counterparts by utilizing direct current (DC) to charge an EV battery. Level 3 chargers are commonly used in public charging stations or commercial settings, enabling drivers to quickly charge their EVs and continue their journeys.

• Life

  Life refers to the length of time a solar energy system can be used and produce electricity efficiently. Over time, the efficiency of solar panels may decrease. Even after their official life is over, it's possible for solar panels to produce some electricity — just not as efficiently as when they were new. The longer the life of a system, the more benefit that can be gained, both in terms of energy production and environmental impact.

• Light Harvesting

  Light harvesting is the process of using special materials and technologies to capture and collect sunlight to generate electricity. Solar panels are the harvesters — when sunlight hits them, the solar cells in the panel capture photons from the rays and use their energy to create an electric current.

• Load

  The load is the electric power consumed by electrical devices and appliances in a home, business or city.

• Load Control

  Load control is the management and regulation of electricity usage in a solar energy system. Technology enables people to decide when certain appliances or devices should be turned on or off based on the availability of solar power, time of use rates and other factors. Load control helps prioritize which devices are most important to power with solar, ensuring the energy is used efficiently and effectively. It’s also capable of automatically managing loads based on pre-configured settings — working in harmony with other energy assets to maximize reliability and minimize both cost and environmental impact of power consumption.

• Main Panel Upgrade

  A main panel upgrade (MPU) is the process of upgrading the main electrical panel in a home or building to accommodate the addition of a solar energy system, solar battery, EV charger or other new appliance. It increases the capacity and capability of the panel to handle the additional electricity generated by solar panels and ensures the electrical system can safely and effectively handle the increased energy flow. An MPU may involve replacing the existing panel with a larger one or adding supplementary equipment.

• Maintenance

  Maintenance is the regular care and attention given to solar panels and other components of a solar energy system to keep them working well. It can involve simple tasks like cleaning the panels to remove dirt and dust, and checking the connections to ensure everything is functioning properly. In many cases, a professional may need to inspect the system to identify and fix any issues that may arise. Regular maintenance helps keep the panels in good condition and may extend the lifespan of the system so it can generate clean energy for as long as possible.

• Maximum Power Point

  Maximum power point refers to the optimal operating condition for a solar panel or array to produce the most electrical power by controlling current and voltage outputs. To find this sweet spot, technology is used to continuously monitor panel performance and adjust electrical parameters accordingly. By operating at the maximum power point, system owners can make the most efficient use of available sunlight and maximize the amount of generated electricity.

• Megawatt

  A megawatt (MW) is a unit of power measuring how much electricity a solar energy system can produce. One megawatt is equal to 1 million watts, or 1,000 kilowatts. A solar power plant with a capacity of just 1 megawatt can produce enough electricity to power dozens of homes and businesses.

• Meter

  A meter is a device that measures the amount of electricity being produced by, and used from, a solar energy system. A solar energy meter measures the amount of electricity a system produces. A utility meter measures total electricity use, while keeping track of any excess electricity generated by solar and sent back to the grid — allowing owners to earn credits or get paid for their contribution. Meters play an important role in keeping track of solar production, usage and savings to ensure owners are getting the most out of their systems.

• Microgrid

  A microgrid is a small-scale electrical system that can generate and distribute power locally, like a mini version of the larger, traditional electrical grid that powers homes and buildings. A microgrid typically consists of different energy sources — including solar panels, battery energy storage systems and other devices to store and manage power. It can work independently or be connected to the main grid, so if there’s a power outage in the larger grid, the microgrid can keep supplying electricity to the local area.

• Microinverter

  A microinverter is a small device attached to individual solar panels, with the job of converting direct current (DC) electricity produced by the panel into alternating current (AC) electricity that can be used in homes or businesses. It ensures the energy generated by solar panels is in the right form for us to use. Additionally, microinverters allow for the monitoring of individual panels’ performance, making it easier to identify and address issues.

• Mismatch

  A mismatch is a situation in which the performance of one or more solar panels is different from the others, which can affect the overall performance of the system. While panels are designed to work together, external factors may cause some to perform better or worse than others. To minimize mismatches, solar technicians carefully select and arrange panels to ensure they have similar characteristics and receive equal sunlight exposure.

• Module

  A module is a collection of solar cells on a panel working together to produce power from the sun. Modules are designed to be durable and weather-resistant to withstand the elements and are often arranged in rows to capture as much sunlight as possible. They are the building blocks of solar panels, and are used to power homes, schools, businesses and cities.

• Monitoring

  Solar energy monitoring uses devices or software that connect to the system and produce data to track efficiency, electricity generation, energy use, diagnostics and other important information that ensures everything is working properly. Monitoring allows solar owners to maximize the benefits of their system and make the necessary adjustments to improve its performance.

• Mount

  A mount is a structure that secures solar panels in place and positions them to capture sunlight effectively. Mounts are commonly installed on rooftops, parking lots and other open areas of land where there is plenty of sunlight.

• National Renewable Energy Laboratory

  The National Renewable Energy Laboratory (NREL) is a national laboratory of the U.S. Department of Energy, and the leading authority on solar energy research and development. NREL conducts research on a variety of topics including solar cell efficiency, solar power plant design and solar energy storage. It also develops and maintains several databases and tools related to solar energy, such as the National Solar Radiation Database and the Solar Power Potential Calculator.

• Net Energy Metering

  Net energy metering (NEM) is a billing arrangement in which customers with solar panels on their property receive credit on their electric bill for the excess electricity they generate and send back to the grid.

• Net-Zero Energy

  Net-zero energy is a state where the total amount of energy consumed by a building or system is equal to the amount of renewable energy it generates, typically through solar power. It means achieving a balance between energy consumption and renewable energy production — resulting in minimal or zero reliance on non-renewable energy sources.

• Nominal Power

  Nominal power is the maximum amount of power that a solar panel can produce under ideal conditions. It’s usually measured in watts (W) and reported by the manufacturer. The nominal power of a solar panel is not the same as its actual output power, which will be lower due to external factors like temperature, sunlight intensity and shading — however, it’s a useful metric for comparing the output of different solar panels.

• Off-Grid

  Off-grid solar is a system that operates independently of the traditional power grid. It relies solely on solar panels and solar battery energy storage to generate and store electricity, without being connected to the utility company’s power lines.

• Off-Load Voltage

  Off-load voltage is the voltage produced by a solar panel when it’s not connected to any load or device. It represents the maximum voltage that a panel can generate under ideal conditions.

• Ohm

  An ohm is a unit of electrical resistance that measures how difficult it is for an electric current to flow through a material or device. The higher the ohm rating, the more difficult it is for current to flow. This is important in solar because it can affect the efficiency of a solar panel. The ohm rating of a solar panel is determined by the materials used to make it.

• Operations & Maintenance

  Operations & maintenance (O&M) refers to the activities that are necessary to keep a solar energy system running smoothly and efficiently. It includes tasks like cleaning the panels, inspecting the equipment and repairing any damage. O&M is important for ensuring that solar systems can generate electricity reliably, efficiently and at a low cost.

• Operating Costs

  Operating costs are the expenses associated with running and maintaining a solar energy system. These costs include routine monitoring, maintenance, repairs, insurance and any necessary administrative fees.

• Operating Point

  The operating point is the specific conditions at which a solar panel operates and produces the maximum power output. It’s determined by factors like the intensity of sunlight, temperature and electrical load. Finding the optimal operating point ensures the highest efficiency and performance of a solar panel.

• Optimum Tilt Angle

  The optimum tilt angle is the angle at which solar panels are positioned to receive the maximum amount of sunlight throughout the year. It’s determined by the geographic location of the solar installation and helps maximize the efficiency and performance of the panels.

• Orientation

  Orientation is the positioning or direction in which solar panels are installed to maximize their exposure to the sun. It involves placing panels in a way that allows them to capture the most sunlight throughout the day — typically facing south in the northern hemisphere, or north in the southern hemisphere.

• Organic Photovoltaics

  Organic photovoltaics (PV) is a type of solar technology that uses organic materials — such as carbon-based polymers — to convert sunlight into electricity. It offers the potential for flexible and lightweight solar panels that can be integrated into various surfaces, like buildings.

• Overvoltage

  Overvoltage is a situation where the voltage in a solar energy system exceeds the safe operating limits. It can occur due to various factors such as system malfunctions or fluctuations in grid voltage. If not addressed, it can potentially damage equipment or pose safety risks.

• Own

  To own solar means a customer financed or paid cash upfront to take control of a system installed on their property. When a customer owns solar, they are responsible for its installation, maintenance and any other associated costs. They also benefit from the electricity generated by the system, which can offset their energy bills and potentially earn them credits or incentives. Solar owners can enjoy the long-term financial and environmental benefits of generating their own clean energy.

• Packing Factor

  Packing factor is the ratio of the actual solar panel area to the total area of a solar module. It indicates how efficiently the solar cells are packed within the module, with a higher packing factor equaling more efficient use of space.

• Panel

  A solar panel is a module made up of many individual solar cells, which are connected to form a larger unit. Solar panels harness the power of the sun to generate electricity for homes, businesses and cities.

• Passive Solar Energy

  Passive solar energy is a type of design that uses the sun’s heat to warm or cool a building without the use of active mechanical systems. Examples include south-facing windows, skylights, light-colored roofs, concrete or stone materials and solar panels.

• Peak Demand

  Peak demand is the highest amount of electricity that’s needed at a particular time. This typically occurs in the afternoon, when people are returning home from work and using ACs and other appliances. Solar panels and solar batteries can help meet peak demand by reducing strain on the grid.

• Photon

  A photon is a particle of light that carries energy. When they hit a solar panel, they’re absorbed by the semiconductor materials in the panel, and the energy is then used to create an electric current. The amount of energy a photon carries depends on its wavelength — shorter wavelengths carry more energy than longer, which is why panels are more efficient at converting sunlight into electricity when the sun is high in the sky.

• Photovoltaics

  Photovoltaics (PV) is a technology that converts sunlight directly into useable electricity. It involves the use of semiconductors — typically made of silicon — which can generate electricity when exposed to sunlight. PV technology is commonly used in solar panels and battery systems.

• Polycrystalline

  Polycrystalline is a type of solar panel technology made from multiple silicon crystals that are fused together. While less expensive to manufacture compared to their monocrystalline counterparts, they have a slightly lower efficiency.

• Power

  Power is the rate at which energy is produced or consumed. It represents how much electricity is being generated by solar panels and is typically measured in watts (W) or kilowatts (kW). The more sunlight a solar panel receives, the more power it can produce.

• Power Purchase Agreement

  A power purchase agreement (PPA) is a contract between a solar company and a customer to purchase the electricity generated by a solar energy system that’s installed on their property and owned by the solar company. The customer agrees to buy the electricity at a fixed price for a set period, which allows them to lock in a lower rate and avoid the upfront costs of installing solar — in a PPA, the solar company is responsible for financing, constructing and maintaining the system.

• Property Assessed Clean Energy

  Property Assessed Clean Energy (PACE) is a U.S. financing program that promotes the adoption of renewable energy like solar in residential and commercial properties. It allows property owners to finance the upfront costs of solar installations and energy efficiency upgrades through a long-term, low-interest loan that’s collected as a special assessment on their property taxes.

• Racking System

  A racking system is a framework or structure that supports and holds solar panels in place. It’s designed to securely mount panels on rooftops, open spaces and other structures. The racking system ensures panels are positioned at the optimal angle to capture sunlight efficiently and allows for proper spacing between the panels for airflow and maintenance access.

• Radiant Energy

  Radiant energy is energy transmitted through electromagnetic waves, particularly sunlight. It travels from the sun to Earth in the form of light and heat and is harnessed by solar panels for conversion into usable electricity.

• Rated Battery Capacity

  Rated battery capacity is the maximum amount of energy a solar battery can store and deliver. It’s typically measured in kilowatt-hours (kWh) and determines how long the battery can power devices or supply power to a home or building. A higher rated battery capacity means the battery can store more energy, allowing for longer periods of power supply or backup when it’s needed.

• Rebate Programs

  Rebate programs are financial incentives offered by government agencies or utility companies to encourage the installation of solar energy systems. It typically provides a partial refund or reimbursement of the cost of purchasing and installing a system, and the amount is based on factors like system size or energy production. Rebate programs help offset the upfront costs of going solar and can make renewable energy more affordable for homeowners and businesses.

• Reflection

  Reflection is the bouncing back of light or energy when it encounters a surface, such as a solar panel. When sunlight hits a panel, some of it is absorbed and converted into electricity, but a portion may also be reflected away. Reflection is an important consideration in solar panel design and placement, as minimizing it — through various techniques like anti-reflective coatings — helps maximize the amount of sunlight captured and converted.

• Refraction

  Refraction is the bending of light as it passes through different materials. When sunlight enters a solar panel, it encounters various layers and materials. The refraction process causes that light to change direction, which can affect how efficiently the panel captures and converts it into electricity. By understanding and controlling refraction, solar panel manufacturers can optimize the design and materials to maximize absorption of sunlight.

• Remote Monitoring

  Remote monitoring is the ability to track and manage the performance of a solar energy system from a distance, using digital technologies and communication networks to gather real-time data on energy production, efficiency and overall health of the system. The data can be accessed through a web-based platform or mobile application, allowing system owners or operators to optimize performance without physically being at the site.

• Renewable Energy

  Renewable energy is energy that’s derived from sources that can be naturally replenished and doesn’t deplete natural resources. Solar is one type of renewable energy that’s harnessed from the sun’s rays using solar panels — offering an environmentally friendly alternative to fossil fuels. Renewable energy can be a reliable, long-term energy solution contributing to a more sustainable and greener future.

• Renewable Energy Credits

  Renewable energy credits (RECs) are certificates that represent the environmental benefits of generating electricity from renewable sources like solar energy. Each REC is equivalent to one unit of clean energy produced, and they can be bought and sold separately from the actual electricity — allowing individuals or businesses to support renewable energy, even if they don’t own a solar energy system. RECs play a role in incentivizing and tracking the adoption of renewable energy sources in the market.

• Renewable Portfolio Standards

  Renewable Portfolio Standards (RPS) are policies or regulations that require a certain percentage of a region’s energy to come from renewable sources, like solar. They’re put in place to promote the adoption of renewable energy and reduce reliance on fossil fuels. RPS typically set specific targets and deadlines for increasing the share of renewables in the overall energy mix. Utilities and energy providers are often required to meet these targets by either generating renewable energy themselves or purchasing renewable energy credits (RECs) from other sources.

• Retail Electricity

  Retail electricity is electricity that’s sold directly to consumers to power homes, businesses, cities and other buildings. Retail electricity can be sourced from solar energy systems, which reduces reliance on electricity purchased from traditional utility companies.

• Rooftop Solar

  Rooftop solar is the installation of solar panels on the roof of a home or building. It's a popular, accessible and space-saving way for individuals and businesses to generate their own clean, renewable energy.

• Semiconductor

  A semiconductor is a material that can conduct electricity under certain conditions, such as silicon. It’s a key component of solar cells, allowing them to absorb photons from sunlight and release electrons to create an electric current. The ability of semiconductors to control the flow of electricity makes them essential for solar energy to work.

• Shading

  Shading refers to an obstruction that blocks sunlight from reaching solar panels. It can be caused by trees, buildings or other objects casting shadows on the panels. Shading reduces the amount of sunlight panels can receive, leading to decreased energy production. Solar installations and locations are typically designed to minimize shading and maximize energy production.

• Silicon

  Silicon is a chemical element and key material used in the production of solar cells, due it its special properties that make it efficient at converting sunlight into electricity. Solar cells are made using thin wafers of silicon, along with other elements that enhance their ability to generate power.

• Snow Load

  Snow load refers to the weight of snow that accumulates on solar panels or solar mounting structures. It’s important to consider because heavy snow accumulation can put stress on panels and impact their performance. Solar installations are typically designed to withstand expected snow loads to ensure the system’s durability and safety. Proper maintenance and snow removal techniques may be used in areas with significant snowfall to optimize panel efficiency.

• Solar Energy

  Solar energy is energy that comes from the sun. It’s a renewable and sustainable source of power. Solar energy is captured and converted into usable electricity through the use of solar panels and is a clean and environmentally friendly alternative to traditional, fossil fuel-based energy sources.

• Solar Power Plant

  A solar power plant is a large-scale facility that generates electricity from sunlight. It consists of numerous solar panels or solar arrays typically installed in an open area, like a field or desert. The electricity generated by a solar power plant is either fed into the grid or used to power nearby communities.

• State of ChangeCharge

  State of charge (SoC) refers to how much energy is taken out or used from a solar battery. When the battery is fully charged, it’s at 100% state of charge, which means it has the maximum amount of energy ready to be used. As electricity is used from the battery, the state of charge decreases. Monitoring and managing the state of charge helps optimize a solar battery’s performance and longevity, and ensures stored energy is used efficiently without damaging the system.

• Storage

  Storage refers to the ability to store excess electricity generated by solar panels for later use. It involves using technologies like batteries to save the energy produced during sunny periods and release it when needed — such as at night or during an outage. Energy storage helps ensure a continuous and reliable power supply, enabling greater energy independence and flexibility in managing electricity consumption.

• Subsystem

  A subsystem is a smaller, specialized component that’s part of the larger solar energy system. It may include components like solar panels, inverters, batteries or tracking mechanisms. Each subsystem has a specific role — like capturing sunlight, converting it into electricity, storing energy or regulating the flow of power. Subsystems are designed to work harmoniously to harness and utilize solar energy effectively.

• Sun

  The sun is the ultimate source of energy — a massive, hot ball of gas that radiates light and heat. The sun’s energy is converted into electricity through solar panels, and its harnessed power enables the generation of clean and environmentally friendly energy.

• System Operator

  A system operator is an individual, entity or organization responsible for managing and coordinating the operation of a solar energy system. They ensure the electricity generated from the system is delivered reliably — monitoring the supply, demand, infrastructure and balance between generation and consumption.

• Tax Credits

  Tax credits are financial incentives provided by state or federal government agencies to encourage the adoption of solar power. They allow individuals or businesses to reduce the amount of tax they owe by a certain percentage of the cost of their solar energy system. These credits can help offset the initial investment in solar, making it more affordable to transition to clean and renewable energy.

• Temperature Coefficient

  Temperature coefficient shows how the performance of a solar panel is affected by changes in temperature. A negative temperature coefficient means the panel’s output decreases as the temperature increases, while a positive coefficient means the output increases with temperature. It’s an important factor to consider when evaluating the efficiency and performance of solar panels under different environmental conditions.

• Terawatt

  A terawatt (TW) is a unit used to measure a very large amount of power or energy. One terawatt is equal to one trillion watts (W), or 1,000 gigawatts (GW). As solar power continues to grow globally, terawatts are often used by solar companies and government agencies to describe the combined power output of multiple solar energy systems.

• Tilt Angle

  A tilt angle is the angle at which solar panels are inclined or tilted relative to the ground. It’s set to optimize the amount of sunlight captured by the panels throughout the year. The ideal tilt angle varies based on factors like location, time of year and specific application.

• Time-of-Use

  Time-of-use (TOU) is a pricing structure where electricity rates vary based on the time of day. Typically, it’s more expensive during peak hours when there is high demand, and lower during off-peak hours. Solar energy and battery users can benefit from TOU by generating their own power or using stored power during peak hours — which can reduce their reliance on expensive grid power.

• Total System Efficiency

  Total system efficiency (TES) is the overall effectiveness of a solar energy system in converting sunlight into usable energy. It considers various factors like panel efficiency, inverters, wiring and other components. Higher TES means more sunlight is effectively captured and converted, which can lead to greater energy output and better utilization of solar resources.

• Tracking

  Tracking is the ability of solar panels to follow the movement of the sun throughout the day. By tracking the sun, panels can maximize their exposure to sunlight and increase energy production. Tracking is typically achieved using motorized single- or dual-axis systems that adjust the tilt and orientation of the panels accordingly.

• Transformer

  A transformer is an electrical device that helps convert electricity from one voltage level to another. They’re important in solar energy systems because they allow for efficient transmission and distribution of panel-generated electricity over long distances.

• Ultraviolet

  Ultraviolet (UV) radiation is a type of light energy that comes from the sun and is invisible to the naked eye. In solar energy, UV radiation is one of the components of sunlight that can be converted into electricity by certain types of solar cells.

• Underperformance

  Underperformance refers to a situation where a solar panel or system is not producing as much energy as expected or desired, due to factors like shading, malfunction, improper installation and more. This can result in lower energy output and reduced efficiency of the system. Regular maintenance, monitoring and troubleshooting can help mitigate underperformance issues.

• Uninterruptible Power Supply

  Uninterruptible power supply (UPS) is a device that provides backup power during electricity outages. It works by storing energy from a solar energy system into a battery. When the main power source is interrupted, the UPS kicks in and supplies the stored energy, ensuring uninterrupted power to critical loads — typically for a limited time period.

• Utility

  A utility is a public or private company that’s responsible for generating and distributing electricity to homes, businesses and cities. Utilities play a role in integrating solar power into the grid, managing the flow of electricity and ensuring a reliable and balanced supply of energy. They may also offer programs and incentives to encourage solar adoption among their customers.

• Useful Energy

  Useful energy is the portion of energy that’s effectively harnessed and converted for use in powering homes and buildings. The goal of solar energy systems is to maximize the production of useful energy, while minimizing losses and inefficiencies.

• Volt

  A volt is a unit that represents the amount of electrical pressure or force in a solar energy system. They are important because they determine the rate at which electricity flows through a circuit. Understanding volts helps gauge the power output and efficiency of solar panels and ensures compatibility with other electrical components in the system.

• Voltage

  Voltage measures the potential difference between two points in a circuit. In a solar energy system, it determines the strength of the electrical current produced by the solar panels. Higher voltage generally results in higher electrical output, though it's usually regulated and converted to a suitable level for use in powering homes and businesses, or grid connection.

• Wafer

  A wafer is a thin slice or disc of semiconductor material, typically made from silicon. These wafers serve as the base for manufacturing solar cells. They’re cut from a larger silicon ingot and undergo various processes to maximize their conversion of sunlight into electricity. Wafers are typically around 200 micrometers thin and have a circular shape. Once multiple wafers are used to create a solar cell, they are then assembled into the panel.

• Warranty

  A solar warranty is a guarantee provided by the manufacturer or installer of solar energy systems that assures customers the system will meet certain standards and remain functional for a specified period. The warranty typically covers defects in materials, workmanship and performance. If any issues arise within the warranty period, the warrantor will repair or replace the affected components at no additional cost. Duration and terms of solar warranties vary.

• Watt

  A watt (W) is a unit used to measure the rate at which power is used or generated. A 100-watt solar panel, for example, can generate 100 watts of electricity under ideal conditions. The wattage helps determine the size and capacity of solar panels and other electrical devices used in solar energy systems. The more watts a solar panel has, the more electricity it can produce.

• Wholesale Power Market

  The wholesale power market refers to the buying and selling of electricity between power generators — like solar farms and utility companies — and retail sellers. Solar is one type of electricity that can be traded in this market, and prices can vary based on factors like supply, demand, weather conditions and market regulations. The wholesale power market plays a crucial role in determining the overall cost and availability of electricity derived from solar energy sources.

• Zenith Angle

  Zenith angle is the angle between the vertical direction (straight up) and the direction of sunlight. It measures how high or low the sun is in the sky — with a zenith angle of 0 degrees meaning the sun is directly overhead, and 90 degrees meaning the sun is on the horizon. This affects the intensity of sunlight reaching a solar panel, with lower angles generally resulting in more direct and stronger sunlight.

• Zero Emission

  Zero emission means the energy production process does not release any harmful greenhouse gases into the environment. Solar energy systems generate electricity without burning fossil fuels, eliminating harmful emissions.

• Zero-Energy Building

  A zero-energy building is a building that produces as much energy as it consumes over a specific period, typically a year. It achieves this balance by incorporating energy-efficient design, insulation, appliances and renewable energy sources like solar panels and batteries. This means the building’s energy needs