Why understand solar jargon?
Solar technology is all well and good, but like most industries, it’s filled with jargon which can leave you in the dark. Here, we demystify some common solar terms to help you get the solar installation that’s right for you.
AC (alternating current)
This is the everyday electrical current we use in our homes. It’s called alternating because the current flows one way, stops, and then flows in the opposite direction. In solar panels, the energy from the sun has to be converted into AC energy before it can be used.
Ampere (amp)
An amp is a unit that measures the flow of electric current. The higher the amp rating, the more power that can flow through the circuit. For example, a laptop uses less than 0.5amps, a standard fridge freezer uses around 1.5 amps, and a kettle uses up to 13amps.
Array (solar array)
An array simply describes your collection of solar panels. It’s also called a solar array.
Base load
This is the minimum amount of power you need to continuously run essential items in your home, for example, your fridge or broadband router. Your base load will help determine the battery capacity you need for your home or business.
Battery storage
The amount of energy that can be stored for later use. Battery storage capacity is measured in kilowatt hours (kWh). The bigger the capacity, the more energy you can store.
Cell (solar cell)
Solar panels are made up of solar cells (also called photovoltaic cells). It’s these cells that absorb energy from the sun. Solar panels used in homes, typically have between 60 and 72 cells, whereas commercial panels can have up to 144. Solar farms are likely to have panels made up of considerably more cells.
DC (direct current)
This is the type of energy produced by solar panels. It flows in one direction unlike AC which flows one way, stops, and then flows in the opposite direction. To convert DC energy into AC energy (which is used in homes and businesses) the DC energy has to go through an inverter (see below).
Efficiency
This describes how good solar panels are at converting solar energy into electricity. Most domestic solar panels have an efficiency rating between 16% and 20%. Higher efficiency panels are available but they’re often too expensive for regular residential users.
Export
Export describes the energy that is sent back to energy suppliers because your panels have generated more energy than you can use or store. Energy suppliers will usually pay you for the electricity you send back.
Feed in tariff (FIT)
This was a government scheme that ran between 2010 and 2019. It meant homeowners with solar panels were paid for the electricity they generated. Although the scheme is now closed to new solar panel installations, people who already receive payments are unaffected.
Grid-tied system
These are the most common type of systems (along with hybrid systems). It’s where your solar array system is connected to the national grid with excess energy that cannot be stored sent to it. It also means if there isn’t enough solar energy, your energy needs can be fulfilled by your regular supplier.
Hybrid grid system
Hybrid systems mean you can store excess energy in batteries for later use, rather than it all flowing back to the national grid.
Import
This is the energy you use that comes in from your supplier in addition to the energy you generate from solar panels.
Inverter
The inverter converts DC energy harnessed from the sun into AC electricity to use in your home or business. The inverter you choose can affect how efficient your system is.
Kilowatt (kW)
A unit of power equal to 1,000 watts (W). Appliances are often shown with a kW rating to show how powerful they are. For example, a 3000W (3kW) kettle is more powerful than a 1500W (1.5kW) kettle and will boil water faster (but also use more electricity).
Kilowatt-hour (kWh)
This measures the amount of energy consumed in one hour. Calculating this means taking into account wattage. For example, if your kettle is 3000 watts and was used continuously for one hour, it would consume 3kWh of electricity. Your electricity bill will show you how many kWh of electricity you use over the billing period.
Kilowatt peak (kWp)
This measurement shows the maximum amount of energy that your solar array can generate. Most arrays used for homes have a capacity of 4kWp which means it can generate up to 4kWh of electricity.
MCS (microgeneration certification scheme)
This scheme certifies firms that install renewable energy, including solar panels, biomass and heat pumps. The scheme also provides quality assurance and offers consumer protection as firms must agree to work to certain standards to gain certification.
Microinverter
Instead of having one inverter for the whole array, each solar panel is fitted with its own microinverter that converts DC energy into AC energy. The big benefit is that efficiency isn’t affected by one poor performing solar panel. Microinverters tend to be pricier than the traditional string inverter (which converts the combined energy from solar panels).
Monocrystalline
This is one of the materials that solar panels can be made from (the other is polycrystalline – see further down for an explanation). Monocrystalline solar cells are made from one piece of silicon and are more efficient and durable than polycrystalline alternatives. However, because of this, monocrystalline panels are generally more expensive.
Mounting system
This is what holds your solar panels in place. The right mounting system for your array will depend on where you put your panels and the type of roof you have. For example, ground mounted panels will use different fixings to panels on a roof. Pitched and flat roofs will also have different mounting systems.
Net metering
This is a type of billing system where your energy supplier credits your account for sending excess energy back to the grid.
Off-grid system
Off-grid systems are not connected to the national grid at all, so all your energy needs must be fulfilled using your solar panels and battery storage. Homes that are completely off-grid will usually also use a back-up power source like a generator.
Panel (solar panel)
This is the panel that absorbs sunlight so that it can be converted into energy. A panel is made up of solar (or photovoltaic) cells which can be monocrystalline or polycrystalline.
Payback period
The estimated length of time it takes for a solar system to pay for itself through energy savings.
Photovoltaic (PV)
Photovoltaic is the process of converting sunlight into usable energy. Solar panels are made up of photovoltaic cells (also known as solar cells) which absorb sunlight (this creates a DC current which the inverter converts to AC energy).
Pitch
This is the angle of your roof in relation to the sun. There’s no one ideal pitch and what’s right for your home or business will depend on where you’re based. Generally, anything between 10° and 50° will be enough to generate good levels of electricity.
Polycrystalline
Also called multicrystalline, this is a type of silicon made up of different silicon crystals merged together (instead of a single piece like monocrystalline). Polycrystalline solar panels are cheaper but not as efficient or durable as those made of monocrystalline silicon.
String inverter
A string inverter connects several solar panels and converts all the DC energy they generate into usable AC electricity. This system is usually cheaper than other types of inverter (such as microinverters). One of the downsides of string inverters is that if one panel isn’t performing as well, it will affect the efficiency of the whole array.
Transformer
This is the specific part of the inverter that converts (transforms) DC energy to AC energy which can then be used in homes and businesses.
Volt
A unit of measurement that describes how strong an electrical current is.
Watt (W)
This measures a unit of electrical power, for example, a 40-watt lightbulb will be less powerful than a 100-watt lightbulb.
Warranty
A guarantee from the manufacturer or installer to repair or replace items that develop a fault within a set period of time. With solar systems, different parts often have differing warranties, for example, there might be a product warranty of 10 years and a power output warranty for 25 years.
The right solar panels for your home or business
Solar panels are a big investment, so you’ll want the most efficient system for your energy needs. At Spartek, we’ve installed solar arrays in both homes and businesses and are proud to offer a ten-year warranty on our workmanship; we’re also fully accredited and part of the MCS scheme. For more help and guidance on choosing the right solar array, call our friendly Norfolk-based team on 01953 882787
