Solar and Renewable Energy Terms Explained
Solar Energy Explained - The solar panels that are installed on the roof of a house or office capture energy from the sun. They take this energy and use it to provide the house or office with electricity and even hot water. Solar panels can even work on cloudy days when the sun isn’t very visible at all. The sun shines on the solar panels and the panels absorb the energy, creating direct current (DC) electricity. The electricity is fed into what is called a solar inverter. This converts the current into alternating current (AC) electricity. The AC current is then used to power the appliances in the home or office.
Alternative - Renewable energy – Energy generated in ways that are less harmful to the environment because they are not as dependent on finite natural resources, particularly fossil fuels such as oil, coal or natural gas. Examples are solar, wind, biomass, geothermal and hydroelectric.
Array – Multiple solar cells make up a solar panel, and multiple panels can be wired together to form a solar array. The more panels you install, the more energy you can expect to generate, but depending on the efficiency of your panels, you may be able to make the same amount of energy with fewer panels. (See solar panel efficiency and solar cell.)
Balance of system (BOS) – All of the other physical parts that make up a solar system outside of the panels: inverters, wiring, mounting hardware, monitoring system.
Efficiency – When referring to a solar cell or a solar panel, efficiency refers to the percentage of sunlight captured and converted into usable electricity. (See solar panel efficiency.)
Electrical (or electric or utility) grid – The interconnected network of equipment that delivers electricityfrom suppliers to consumers. Often called "the grid," this infrastructure is made up of generating stations that produce electrical power; high-voltage transmission lines that carry power from distant sources to demand centres; and distribution lines that connect individual customers to the system. In other words, the poles and wires that transport electricity from where it's made to your home or business.
Ground-mounted solar – A solar array installed on land; used primarily for large-scale commercial and utility-scale solar projects such as power plants that generate power for thousands of homes and businesses.
Inverter – A solar power system generates direct current (DC) electricity, yet homes and businesses use alternating current (AC) electricity to power electronic devices. A solar hybrid inverter takes the DC electricity from the solar system and uses it to create AC electricity. Inverters are like the brains of the solar system. Along with converting DC to AC power, they also provide ground fault protection and system stats including voltage and current on AC and DC circuits and energy production.
Micro-inverter – The introduction of micro-inverters is one of the biggest technology shifts in the photovoltaic (PV) industry. Placed on the back of each solar panel, a micro-inverter optimises energy production for each individual solar panel, not just for an entire solar system, as central inverters do. This enables every solar panel to perform at its maximum potential. It means one underperforming solar panel won't drag down the performance of the entire solar array, as opposed to central inverters that optimise for the weakest link.
Mounting hardware – The racking and mounting equipment used to secure solar panels to rooftops (or to trackers in ground mounted power plant installations) and to each other; often made with lightweight aluminium frames and clips capable of withstanding the elements while minimising impact to the roof.
Net metering – When a grid-tied solar system produces more energy than is needed, the excess power is sent to the electrical grid to be redistributed where it's needed. This is called "back feeding" the grid. At night, the grid will provide conventionally created power for the solar customer's use. A net meter records the energy sent compared to the energy received from the grid and credits or charges the user according to local rates and rules. Forty-four states currently offer net & metering or some variation of it.
Operations and maintenance (O&M) – The ongoing operational needs of a solar system, including cleaning, repairs, replacement of parts, bill management and so on; primarily refers to larger-scale commercial and utility-scale solar systems.
Photovoltaic (PV) – PV Panels convert sunlight to electricity through a naturally occurring process in certain types of material, which are called semiconductors. When photons (energy particles) from the sun hit semiconducting materials such as silicon, electrons are knocked free from their atoms. If conductors are attached to the positive and negative sides of a solar cell, it forms an electrical circuit. When electrons flow through such a circuit, they generate electricity, powering electrical devices or sending electricity to the grid.
Renewable energy – Energy generated from sources that naturally continually renew themselves, such as sunlight, wind, geothermal heat or tidal movement.
Solar batteries (or storage) – Solar storage systems are high-capacity rechargeable batteries (or battery banks) that can store excess energy generated by a solar system for use at night or as a backup during emergency grid outages or other times when the solar system cannot generate energy in real time. Batteries suited for solar incorporate a variety of technologies, including lead acid, lithium-ion or flow batteries.
Solar canopies – Solar panel arrays that are raised above the ground on structures that leave the land underneath usable for other purposes, such as parking lots.
Solar carports – Solar panel arrays that are raised above parking lots to provide both shade and energy production.
Solar cell – A single light-capturing unit in a PV solar panel; solar cells are made of silicon, like semiconductors. They are constructed with a positive layer and a negative layer, which together create an electric field, just like in a battery, and are extremely thin and light.
Solar panel efficiency – The percentage of sunlight that solar panels can convert to electricity. The first solar panels had about 6 percent efficiency. SunPower solar panels have the world record for efficiency of commercially available panels — 22.8 percent,*Green, M. A., et. al. "Solar Cell Efficiency Tables (version 48)," Progress in Photovoltaics, 2016 but a panel we recently developed in the lab was verified at 24.1% efficiency.*NREL PV Report #2K1656A, June 2016.Solar panel efficiency matters because high-efficiency panels can generate more power in less space over time than conventional panels, so you need fewer panels to get a higher return on your investment.
Solar dealer – A company that sells solar equipment to homeowners, businesses and other organisations; may sell products from one or many manufacturers and may also provide installation and maintenance services.
Solar design – The layout and orientation of a solar system, optimised for maximum energy production based on roof or land characteristics, the angle of the sun, shading, climate and aesthetic appeal.
Solar installer – An expert or company that specialises in delivering and physically installing solar equipment on buildings and homes.
Solar monitoring – Specialised software used to track and manage energy generation and usage, billing, carbon offsets and more; can be accessed via a mobile device, home computer or a remote operations centre.
Solar panel (or module) – PV solar panels are made up of many solar cells linked together to form a circuit and are mounted in a frame. PV solar panels generate DC electricity, which must then be converted to AC electricity by an inverter because the U.S. electrical grid uses AC power.
Solar panel cleaning – Rooftop home solar panels usually are naturally cleaned by seasonal rains or melting snow, but excessive build up of dirt or debris can reduce efficiency. Panels can be sprayed off when they're cool (in the early morning or evening) with a garden hose and gently wiped with a soft sponge or cloth, or owners can hire a cleaning professional for the job. SunPower uses robots to clean large-scale solar ground-mounted solar systems more quickly and with less water than manually cleaning methods.
Solar power plant – A large-scale, usually ground-mounted solar array built for utility or commercial use.
Solar shingles (or tiles) – Thin-film photovoltaic strips or tiles that can be applied directly to roofing cloth, just like regular roofing shingles. These solar shingles capture sunlight and convert it to electricity but do so less efficiently.
Thin-film solar – PV solar technology constructed with very thin layers of PV material to create lightweight, often flexible sheets of solar energy-producing modules. Thin-film solar is generally cheaper and more versatile than conventional solar panels, but it is also less efficient and degrades more quickly over time.
Zero net energy — Zero net energy (ZNE) (also referred to as net zero energy) identifies homes or buildings that generate as much energy as they consume, usually via a combination of green building techniques that include a solar energy system.
Cell A photovoltaic cell is a semiconductor diode that converts light into electricity (direct current/ DC). Multiple solar cells can be connected together electrically to form modules.
Module A group of PV cells sealed in a protective layer to protect them from the environment.
Panel These can include one or more modules wired together to create one whole panel.
Array Consisting of a number of wired together solar panels or modules, an array can vary dramatically in size depending on the system requirements.
Inverter Converts direct current (DC) to alternating current (AC). This means the electricity generated by your solar panels which is DC can be inverted to AC for use from sockets/ outlets.
Storage batteries allow you to capture and store energy created by a solar PV system to be used at any time, for example in the evening when panels may not be generating.
Solar Thermal Also known as solar water heating, solar thermal uses energy from the sun (absorbed by collectors) to heat water.
Photovoltaic (PV) Solar Collecting and converting energy from the sun (solar radiation) into direct current (DC) electricity, which is then inverted into alternating current (AC) for use.
Installation
Roof mounted Mounting systems are used to attach solar panels to the surface of a roof
Ground mounted Solar arrays mounted on a framework on the ground - often a good alternative for anyone whose property is unsuitable for roof mounted panels.
Farm (also known as solar fields) Large areas of land where solar panels are set up to generate energy at scale.
Concentrated solar Mirrors or lenses are used to concentrate sunlight and using heat to generate electricity. The most common types are power tower, dish, parabolic and linear.
Materials
Monocrystalline A kind of photovoltaic cell made from a slice of single-crystal silicon, where the entire cell is oriented in one direction.
Polycrystalline (also referred to as Multicrystalline) A photovoltaic material made up of silicon offcuts, creating tiny individual crystals which are oriented in various directions.
Amorphous A thin-film photovoltaic cell made from non-crystalline silicon that has a more glassy structure.
Energy
Kilowatt (kW) Unit of measurement for electrical power (equal to 1000 watts).
Kilowatt-hour (kWh) A measure of energy equal to using 1000 watts per hour.
Renewable energy Energy generated from a source that is not used up/ depleted in the process. This includes solar, wind and tidal energy generation.
Alternating current (AC) An electric current that constantly changes direction.
Direct current (DC) An electric current that only flows in one direction.
Electrical grid A network of transmission lines that deliver electricity from suppliers to consumers.
Off grid To have no dependence on the grid electricity supply.
.