Anyone considering a solar panel installation has likely done some online research. You may be interested in the technology behind solar panels, what they’re made of, and how they can help reduce our planet’s CO2 levels.
But wading through the technical aspects of renewables can be tiring, especially when you want to get to the point. Having already helped over 45,000 homes make the switch to solar, we know how important it is that our customers know precisely what they’re getting.
Project Solar is here to jargon-bust solar terminology with our comprehensive list.
AC (Alternating Current)
‘Alternating current’ is the type of electricity used by homes and businesses across the UK.
Solar panels generate Direct Current (DC), so an inverter is required to convert DC into AC, which can then be used in homes.
DC (Direct Current)
‘Direct Current’ (DC) is a type of electrical current that flows only in a single direction. In a solar panel system, the photovoltaic cells generate DC electricity when they absorb sunlight. An inverter then converts this to Alternating Current (AC) using inverters.
Albedo
‘Albedo’ is a measurement of how reflective a surface is.
Where solar energy is concerned, surfaces with higher albedo (e.g., light-coloured roofs or ground materials) can reflect more sunlight, which may reduce the efficiency of solar panels by decreasing the amount of direct sunlight they absorb.
Array
An ‘array’ or ‘solar array’ describes how your solar panels are arranged. They could be made up of two or two hundred modules connected to function as a single electricity-producing unit.
Azimuth
The term ‘Azimuth’ refers to the angle that your solar panels face on a roof. It is measured from true north. For example, the optimal azimuth angle for solar panels is typically 180°, meaning they should face southwards for maximum light exposure.
Base Load
‘Base load’ refers to the constant electricity demands of a home or business over a specific period (usually 24 hours).
They may include appliances like fridge-freezers, Wi-Fi boxes, and even security systems. Your chosen installer must discuss the base load to determine the correct battery capacity for your home.
Battery Storage
‘Battery storage’ is the process of storing excess electricity generated by solar panels for a later date, such as at night or on days with low sunlight.
As many homeowners may not be at the property during peak sunlight levels, this energy can either be sold back to the National Grid or conserved in a battery.
Bifacial Solar Panels
These are a type of panel capable of capturing sunlight on both their front and rear surfaces.
Their design allows them to use direct sunlight on the front and reflected light (albedo) on the rear.
Carbon Dioxide (CO₂)
‘Carbon dioxide’ is a greenhouse gas that contributes to global warming. It occurs naturally in Earth’s atmosphere at trace levels, but human activities (like the combustion of fossil fuels) have caused it to increase to dangerous levels.
Degradation
In this context, ‘degradation’ refers to the process of an item physically wearing down over time.
Solar panels don’t have many complex, moving parts, so they often have a longer lifespan than other home or business appliances. However, they may experience a gradual decline in their power output over time.
Diffuse Insolation
The term ‘diffuse insolation’ refers to the amount of sunlight that reaches the Earth’s surface after being scattered by atmospheric components such as clouds, fog, haze, dust, or other obstructions.
Direct Insolation
‘Direction insolation’, however, describes the solar radiation that reaches the Earth’s surface in a straight line from the Sun without being scattered or diffused.
Efficiency
‘Efficiency’, in the context of solar panel production, is the percentage of sunlight that a panel can convert into usable electricity.
Electric Grid
The ‘electric grid’, also known as the ‘National Grid’, is an interconnected network responsible for delivering electricity from producers to homes and businesses across the UK.
Electricity Metre
A device that measures the amount of electrical energy consumed by a home, business, or electronic device. Electricity meters can also track the amount of energy that is generated by a solar panel system and fed back into the grid.
Export
‘Export’ is the excess electricity generated by a solar power system that isn’t consumed on-site and is, instead, fed back into the National Grid.
Feed-in Tariff (FIT)
A policy mechanism designed to encourage the uptake of renewable energy sources by providing long-term contracts and cost-based purchase prices to producers. The scheme closed in 2019.
Gigawatt (GW)
A unit of power equal to one billion watts (1 GW = 1,000,000,000 watts). Gigawatts are often used to express the total electrical power production of a country or power plant.
Greenhouse Gas (GHG)
Gases in Earth’s atmosphere that trap heat. Common GHGs include carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and fluorinated gases.
Grid-Tied System
A solar power installation connected to the national electricity grid.
Immersion Diverter
A device that redirects excess electricity generated by solar panels to power an immersion heater in a hot water tank. Instead of exporting surplus energy to the grid, it can be used to heat water.
Import
In a solar energy context, import refers to electricity drawn from the national grid when a household’s consumption exceeds the production from its solar panels (and any backup energy).
Inverter
A component in solar systems that converts the Direct Current (DC) electricity produced by solar panels into Alternating Current (AC).
Kilowatt (kW)
A unit of power equal to 1,000 watts.
Kilowatt Hour (kWh)
A unit of energy representing the consumption of one kilowatt over one hour.
Kilowatt Peak (kWp)
A measure of the maximum output of a solar system under standard test conditions. It indicates the system’s peak capacity to generate electricity.
Megawatt (MW)
A unit of power equal to one million watts or 1,000 kilowatts.
Monocrystalline Solar Cells
Monocrystalline solar cells are made from a single piece of silicon and may operate at higher efficiencies.
Mounting System
The infrastructure used to securely attach solar panels to surfaces such as roofs or the ground.
Net Metering
A billing mechanism that credits solar energy system owners for the electricity they add to the grid. In the UK, the Smart Export Guarantee (SEG) means homeowners can receive payments for excess energy exported back to the National Grid.
Net Zero
The UK’s ‘Net Zero 2050’ policy aims to balance the amount of greenhouse gas emissions produced and the amount removed from the atmosphere.
Off-Grid
A solar power system that isn’t connected to the national electricity grid. An ‘off-grid’ solar panel array relies solely on solar panels and battery storage to meet energy needs.
Open-Circuit Voltage (VOC)
‘Open-circuit voltage’ is a key metric in measuring a solar panel’s potential performance. It is the maximum voltage available from a solar cell when no external load is connected (meaning no current is flowing).
Panel/Module
A ‘solar panel’, also known as a ‘module’, consists of multiple interconnected solar cells enclosed in a protective frame.
Perovskite Solar Cells
These are a type of solar cell made using a high-efficiency, low-cost compound called ‘perovskite’. While perovskite solar cells are not available for residential use, they are slowly being rolled out commercially.
Photovoltaic (PV)
‘Photovoltaic’, or ‘PV’ describes the technology behind solar panels. PV systems capture solar energy and transform it into usable electrical power.
Pitch
‘Pitch’ is the angle of inclination of a roof or mounted solar panel relative to the horizontal plane.
Polycrystalline Solar Cells
Also known as multicrystalline cells, these are made from silicon crystals that have been melted together.
Rated Maximum Power (Pmax)
‘Pmax’ is the highest power output a solar panel can achieve under standard test conditions, typically measured in watts.
Smart Export Guarantee (SEG)
A UK government initiative that requires certain electricity suppliers to pay small-scale, low-carbon energy producers (e.g., residential homes) for excess electricity exported back to the National Grid.
Introduced in 2020, the SEG replaced the previous Feed-in Tariff (FIT) scheme, which was retired in 2019.
Solar Array
A collection of multiple connected solar panels.
Solar Battery
A device that stores energy generated by solar panels to be used at a later date.
Solar Cells
Also known as ‘photovoltaic cells’, these are semiconductor devices that convert sunlight directly into electricity. Multiple solar cells are interconnected to form a solar panel (also known as a ‘module’).
Solar Charge Controllers
Devices that regulate the voltage and current coming from solar panels to prevent overcharging.
Solar Inverter
A device that converts DC electricity into AC (the electricity used to power most household appliances).
Solar Thermal Panels
Devices that capture sunlight to generate heat, mainly used for heating water for residential and commercial purposes.
Standard Test Conditions (STC)
A set of laboratory conditions used to measure and rate the performance of solar panels.
Temperature Coefficient
A parameter that indicates how a solar panel’s performance changes with temperature variations.
Terawatt (TW)
A unit of power equal to one trillion watts (1 TW = 1,000,000,000,000 W). This measurement is often used to describe the large-scale capacity of national or even global power generation.
Watt (W)
The standard unit of power that measures the rate of energy transfer, equivalent to one joule per second.
Watt-Peak (Wp)
The maximum electrical power output of a solar panel under standard test conditions.
Join the solar takeover with Project Solar!
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Our team of experienced installers is here to get you started. As the UK’s top installer, we’re here to help homes and businesses generate cleaner energy for the future. Contact us to learn more about what we offer.