In here you’ll find a quick definition of what all those acronyms and buzzwords used in solar energy talk mean.
Some will have links to references where you can learn more.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Albedo
A fractional measure, from 0 to 1, of the diffuse scattering of light from (or “blackness” to “whiteness” of) a surface, where 0 is darkest (absorbing all light) and 1 is lightest (scattering all light). For example, the “albedo” of the Earth is around 0.3 – meaning about 30 percent of the light from the sun hitting the Earth is diffusely reflected. A black asphalt surface has very low albedo. Charcoal has one the lowest albedos at 0.04 making it one of darkest “blacks”. Fresh snowfall has very high albedo (typically 0.9 or more) – hence that “snow blindness”. Source: Wikipedia.
Amorphous Glass
A glass surface that is coated with paint like photovoltaic material that has no solid crystal-like structure to it. Amorphous glass solar panels consist of many bands or rectangles in which a powdered (amorphous) photovoltaic material is painted or sprayed on.
Battery Acid
“Battery acid” is technically the solution of distilled water (H2O) and 37% sulfuric acid (H2SO4) commonly used in wet cell lead acid batteries such as automotive batteries.
Bypass Diode
A bypass diode (or shunt diode) is an electronic semiconductor component (usually a Schottky diode) that allows DC voltage generated by solar cells that are in sunlight, and producing power, to safely go around cells, strings of cells or whole panels that are not producing sufficient power (e.g. in shade or damaged/defective, etc). Many modern solar panels contain one or more built-in bypass diodes to guard groups/strings of solar cells within the panel.
Inverter
An electronic device that converts DC (Direct Current) voltage from batteries or solar cells to AC (Alternating Current) so that it can power devices that you normally plug into an outlet at home. For example lamps, laptop chargers, a television, modem, etc – up to the maximum rating of the inverter or your DC power source.
A “pure sine wave inverter” is an inverter that generates its AC in the true sine wave shape you normally get from a standard AC outlet on the grid. Many low-cost inverters generate a more “square wave” shape that works fine for most appliances but may generate more EMI (electro-magnetic interference) noise than from a sine wave AC source.
IP (Ingress Protection) Code
The IP or Ingress Protection code is a rating of dust and water resistance. It is the letters “IP” followed by two digits – IPxx. The first digit is a scale of 0 to 6 for dust resistance. The second digit is a scale of 0 to 9 for water resistance. 0 means no dust or water resistance. The top value means completely dust or water proof. For solar panels and other equipment that is outdoors, higher IP code ratings are important. Reference: Wikipedia IP Code
Islanding
A situation where a section of electrical grid that is supposed to be shut down remains energized due to power being injected from another source such as generator. Islanding is a dangerous situation as crews working on electrical cables/transformers can be electrocuted by this power that is being fed into the system. Modern grid-tied inverters and backup solar generators, when properly installed, include safeguards against islanding.
LiFePO4 (or LFP) Battery
A LiFePO or LFP battery (short for Lithium Iron Phosphate, or Lithium Ferrous Phosphate (LFP), LiFePO₄) is a newer type of lithium-ion battery with high safety, longer lifespan, and improved thermal stability.
They are much less prone to overheating or fire than other lithium batteries, can handle thousands of charge cycles, and deliver a more consistent power output. This makes them especially popular in solar energy storage, home backup systems, RVs, and electric vehicles.
While LiFePO batteries are slightly heavier and have lower energy density than some lithium-ion types, their durability and safety make them a reliable, long-term choice.
Microgrid
A small localized electrical grid that can operate independent off of or tied to the main electrical grid. Moderns solar powered homes and properties can be setup to pool together and form a microgrid that is self-sufficient in the event of a power outage. Reference: U.S. Department of Energy: Microgrid Overview
Microinverter
A small Inverter that operates locally with a DC electricity source to produce AC. Micro-inverters can be built right into individual solar panels providing AC output directly from the panel. Micro-inverters usually have to ability to be chained together and synchronize to produce increased AC power.
Module-Level Power Electronics (MLPE)
Module-level power electronics is the integration of electronic components such as power optimizers, micro-inverters, shade sensors and other electronics into the body of a solar panel. This allows close electronic monitoring and optimization at each individual solar panel. MLPEs can communicate status, coordinate or synchronize with each another and central controllers to optimize total energy conversion to electricity.
Monocrystalline (aka “mono-Si”)
Of a single pure crystal form. A monocrystalline solar cell is one that is composed of a solid slice of silicon. These are black in color and are usually round or have rounded corners. These are the most efficient type of solar cell and are widely used in modern solar panels. See also Polycrystalline solar cells.
MPPT
Maximum Power Point Tracking (MPPT) refers to a type of solar panel battery charge controller that delivers optimized charging to your battery system throughout the day as output from your solar panels changes. MPPT has become the preference over older, simpler PWM based charge controllers.
Ohm
A unit of measurement for electrical resistance to voltage that can be used to determine how much current (in Amps) at a given voltage an electrical device will require. See Ohm’s Law for details and history. Resistance in ohms is often represented by the Greek letter Omega – Ω.
Perovskite Solar Cells
A new high-efficiency solar cell made with metal-halide perovskites (materials with a distinctive crystal structure combining organic ions, metals, and halogens) as the light-absorbing active layer. These thin-film cells absorb light efficiently, exciting electrons that generate electric power. Perovskites can be combined with other technologies like silicon to create tandem cells, potentially surpassing the efficiency of individual technologies.
Since 2009, perovskite solar cells have rapidly advanced, reaching over 26% efficiency in small-area devices and nearly 34% in tandem configurations. Their potential lies in low-cost production via low-temperature processes and ink-based manufacturing, resilience to structural defects, and compatibility with various photovoltaic technologies. However, despite impressive lab-scale performance, commercial scalability and long-term stability remain challenges under active research and development.
Photovoltaic (PV)
Something that is “photovoltaic” is capable of turning light “photo” into voltage “volt”iac.
The individual cells that make up a solar panel are “Photovoltaic Cells”, or commonly just called “Solar Cells”.
Photovoltaic Cell
A photo-voltaic cell is an individual unit (or cell) that converts light into voltage. A typical silicon photovoltaic cell generates just over a half volt at a current determined by the surface area of the cell.
A solar panel consists of many photovoltaic cells connected together in series/parallel configurations for a specific rated voltage and current output to be used in a solar electric system.
Photovoltaic Paint (aka “Solar Paint”)
A specialized paint that contains micro-semiconductor particles that can be applied to any surface, effectively turning it into an electricity producing solar panel when it dries.
Polycrystalline (aka “poly-Si”)
A mixture of different crystalline materials, each with their own crystalline structure but forming a single solid material. A polycrystalline solar cell is one made of many fragments of silicon that are heated so that they fuse together to (re)form a solid crystal. This mix of silicon fragments forms a sparkling pattern that is visible in reflected light. See also Monocrystalline solar cells.
PWM
Pulse Width Modulation (PWM) – the rapid switching of a DC input voltage between “On” and “Off” to produce an average DC that is a percentage of the input voltage. This percentage is determined by the ratio of on time to off time. The more the “off” the lower the percentage. This is done electronically at a high enough frequency (and through a filter) that it appears to the receiver as a steady DC voltage at a set percentage of the input voltage.
PWM technology is used for example to regulate raw variable voltage output from solar panels to a usable stable voltage that can be used by equipment consuming solar power. Most commonly used in a solar battery charge controller to provide safe, controlled charging of batteries. See also MPPT.
Thin Film
“Thin film” is a thin photovoltaic compound that is applied to a surfaces such as glass, metal or flexible plastics. Thin film technology is much thinner than conventional silicon wafer photovoltaic cells and is often used in flexible solar panels, photovoltaic paint, non-flat surfaces and other applications where rigid brittle silicon PV cells are not practical. Thin Film solar cell