Ever tried researching solar power, only to find yourself struggling to understand the difference between a kilowatt and a kilowatt-hour, or what the heck a Powerwall is?
If so, you’re not alone. Solar power is jargon-heavy.
But does it really matter? I mean, you drive your car for a lifetime never knowing what a cam is or what a conrod does. (Yes, car parts). But knowing what a steering wheel does has been very handy for you right?
So why be solar slang savvy?
Well, we certainly know what a USB cable is now, and we know what data usage is all about. It’s new technology we now take for granted.
As new consumable technology (the technology we use, like washing machines and stuff) comes kicking and screaming into the modern era, we use it, and it becomes integrated into daily living.
So, we learn as much as we need to learn to use it in a capacity that serves our needs. The more we know, the better it serves us.
Solar electricity and all its peripherals are a new(ish) consumable technology that many of us have already adapted to our daily life. Many more of us will integrate said technology into our homes and businesses in the near future.
That’s why we’ve created this easy-to-understand glossary of all the wonderful words they don’t teach you in school, but that are vitally important (most of them anyway) to getting solar right.
Like the ‘steering wheel’ and the ‘conrod’ in the car example above, some terms you will find very important, while others will seem a little esoteric, or make you go ‘What the?’ Who cares!
Well, if you have at least been introduced to the terms, you can decide their relative importance to you.
To make things easy for you, we’ll even show you how to use the term in a sentence. Look to the end of the definition for a way to drop it into a conversation (if a little flippantly).
This ‘solar dictionary’ aims to be a fully comprehensive, alphabetical guide to the solar industry. However, it is not complete and we will continue to improve and add to this page.
So, if you have any suggestions, please contact us and let us know! Otherwise, enjoy this roadmap to the linguistics of solar power, battery storage, and everything in between.
An AC coupled solar component is connected to the system via AC current. A component can be called AC coupled if it uses DC current but is connected to an inverter, which inverts the electricity into AC.
“The AC coupling. Keeping contrary components connected.”
An alternating current (AC) is an electrical current that alternates its direction within a circuit over time. Your home runs on AC.
To explain the reason behind using both AC and DC and their inherent differences would require a few pages of definitions and perhaps a degree in electronics.
In brief however, we use alternating current in our homes because it travels best over long distance (i.e., from the power station) and is easy to transform from high voltage to lower voltage.
Feel free to research more on this, but it’s not critical for you to know, and trying to work it out will leave the less technical amongst us tired and confused.
“Alternating current, just like my business plans—frequently changing direction.”
An ampere is a measure of current within a circuit. Specifically, it measures the amount of electric energy that passes through a point within the circuit per second. One ampere is equal to 6.242×1018 electrons or protons passing through a circuit per second.
Yes, that's impressive mathematics with some huge numbers. But what does it mean for you?
The ampere, or ‘amp’ as you may have heard it called, can be quite important for those that want to get a true and accurate measure of the electricity they consume. Each appliance has a sticker on it telling you how many amps it draws when in operation.
Your washing machine and clothes dryer pull a lot of amps. They cost more to run than a clock radio. Knowing this allows you to plan your power usage for greater efficiency.
For example, if you already have solar, use your dryer and washing machine during the day when they are powered from the sun.
“When my daughter gets angry, she draws more amps than an industrial air conditioner.”
Older electricity meters used analogue displays. These meters cannot perform net metering—that is, measuring both the amount of power taken from the grid and the amount contributed.
Analog meters track your electricity usage generally and can be used to check the accuracy of your bills on a monthly basis.
Converting to solar would likely see a change from an analogue meter to a digital meter. Most of us still probably use the old school analogue meter.
“Analog, pretty old-school but still kinda cool and useful like bakelite, black and white and turntables.”
An array refers generally to two or more connected solar panels within a solar electrical system. It’s a collective term, much like a gaggle of geese, a murder of crows or a school of fish...but all technical and space age.
“We were the first in our neighbourhood to have a solar array. Looking around now there’s a whole array of arrays.”
A battery charger, or battery inverter, is a two-way inverter that allows a DC battery component to export power in AC, as well as convert incoming AC power into DC.
No doubt, you have a number of them in your house or shed. Dad has all his cordless tool batteries sitting in the charger as we speak. (Always in the charger, never being used.)
“Funny to think of it, but our house is actually one big battery charger.”
A solar battery has a lifespan of 5 to 15 years. There are variables here. Brand, type and the frequency of charge and discharge will all impact the life of your battery. As will exposure to the elements.
Where your home battery is concerned, you will most likely be using a Lithium-ion battery. You will most likely be guaranteed a certain number of charges and discharges. This will vary according to the manufacturer.
Always read the fine print and consult your solar professional. Compare brands and prices.
“What is it with batteries and Christmas day? We need a battery warranty to cover dad neglecting to purchase any. Batteries not included!.”
A busbar is a metal plate placed within a solar panel that conducts the freed electrons within the solar cell.
This is information that is more useful for your electrician, but at least now, when the sparky says ‘busbar’ you can take it in your stride because you know what it is.
“Even though I showed my husband the busbar in the electrical system, he still thinks a busbar is a place to drink on public transport.”
A battery cycle life refers to the number of charging cycles the battery can undergo before its capacity is reduced to 80% of its original size. It is suggested that lithium-ion batteries are retired once their capacity is reduced by 20%.
Always check this figure with your supplier when purchasing a battery. This technology has improved dramatically, and rechargeable batteries last a considerable amount of time now.
Your retailer will also provide tips on how to get the best from your battery, ensuring it lasts longer.
“Interestingly, explaining cycle life to the kids was a lot easier than explaining the cycle of life.”
A DC coupled component is connected to a solar system using DC current.
“Your DC coupling connects like with like. The perfect marriage. Everyone is heading in the one direction.”
DC optimisers are panel level MPPT optimisers used within string inverter systems. They enable higher yields and better production under shade etc.
Greater efficiency—happy days. Again, check the value of installing a DC optimiser by weighing the purchase cost versus the potential savings over time.
“Our DC optimizer has given us 10 percent more yield on the shady days. Perhaps I could plug my husband in, I get zero percent out of him when he’s in the shade.”
Digital meters use digital methods to measure the amount of energy used from the grid. They are able to measure power usage on a daily basis. They transmit power usage information via low-level wireless radio signals.
The great benefit is that the modern digital meter also measures the electricity you return to the grid. See ‘Tariffs’.
“Digital. It’s simply a term meaning the kids can understand it and the grandparents can’t.”
A direct current (DC) is an electrical current that flows in one direction and has a stable voltage across a circuit. Examples of devices that use DC current would be a battery operated torch or your car.
Your solar panels are also DC. However, our homes use Alternating Current (AC). So, to use DC power in the home, it passes through a device called an inverter to change the power from DC to AC.
“We prefer direct current. We love a charge that knows where it's going without changing its mind.”
Electrical efficiency refers to how effective any appliance or component is at using electricity to perform its function. In the case of an inverter, electrical efficiency refers to how efficient the inverter is at converting DC into AC.
Even the most basic circuits have electrical inefficiencies, as even the most conductive materials have some electrical resistance.
“The human side of a solar cell: innate inefficiencies, just like the rest of us.”
The efficiency of a solar panel refers to the percentage amount of light that a solar panel can absorb. That is, if 100 photons hit a panel with a 15% efficiency, 15 would be absorbed and turned into electricity.
Obviously, the higher conversion rate means money in your pocket. Again, this is an important question to ask your supplier? How efficient are the panels within my budget? Will a higher investment in efficiency now provide greater returns over time?
How do brands compare?
“My grandfather keeps telling me, the balder he gets, the more efficient his haircuts are.”
“Just like a squeaky clean solar panel,” he says.
Energy Storage Unit
The failure rate of a particular solar component refers to the ratio of manufactured units which experience less than satisfactory performance or total failure within the warranty period when compared to functioning units.
‘REC has a failure rate of 1 in 10,000. That means for every 10,000 panels produced, one will fail within the warranty period.’
As long as it is covered by the manufacturers or installers warranty, then you are protected. Make sure you understand your warranty completely.
It is also critical that you understand the difference between your installer’s warranty and the warranty offered by manufacturers of individual components within your solar electrical system.
“If only I could get my souffle failure rate to that of the failure rate of solar panels, 1 in 1000, wow, I’d get a Michelin star.”
Flow batteries work by pumping negatively and positively charged liquids past each other. The Redflow battery is one such example of a flow battery.
While flow batteries have the advantage of extreme longevity, their size to power output is far less than that of other conventional technologies.
Expect developments in this technology. The longevity, or the number of times this battery can be charged and discharged, far outways that of a lithium-ion battery.
“Nothing lasts as long as a flow battery. If only I could power my husband with one.”
Half Cut Cells
Half cut solar cells are half the size of a standard cell. They are split to reduce resistance from within the cell, increasing the panel’s reliability and performance.
It’s just a solar cell half the size of a normal solar cell. This is a new innovation and is worth knowing about.
To put it in super easy terms. A full-size cell will produce more energy but will produce it less efficiently than a half cut cell. The half cut cell may produce less energy, but what it produces, it produces more efficiently.
Boffins pundits and manufacturers are suggesting a 5 to 8-watt increase in power using half cut cells.
“Our solar cells are half cut. No, not a little bit drunk—on the contrary, more efficient.”
Home Battery (Energy Storage Unit, Solar Battery)
A home battery, otherwise known as a solar battery or energy storage unit, refers to any electrical storage device used for residential purposes. A home battery’s main function is to store solar energy for later use.
Efficient and affordable rechargeable batteries that retain enough power to run our homes is kind of the last bastion of nailing the whole renewable domestic power thing.
Imagine, sun and wind run our appliances and charge the battery. When there is no sun or wind, the battery takes over. It’s happening now, people. Look forward to significant developments in this technology.
‘If only we had a home battery, we wouldn’t have to sell our power for pennies on the dollar!’
A solar inverter is one of the major components that make up a solar system. An inverter is responsible for converting DC power into AC power. Inverters are often responsible for monitoring and managing the system.
This is the engine room of your solar electrical system, the business end. Do your research and install the best one your budget allows.
Explaining the intricate workings of an inverter and the change from DC to AC could potentially hurt our brains. For those of us keen to take on the challenge, here is a great introduction.
“I think the taxi driver I had this morning was plugged into an inverter. I told him the direct route but he insisted on alternating it.”
Inverter warranties can be as long as 25 years, as some manufacturers provide an option to purchase an extended warranty, but most inverter warranties are 5 to 10 years.
Check the fine print and understand what is covered. Components within the inverter may be subject to different warranty periods.
“My technician told me that my inverter inadvertently began inverting the inverted. Thank goodness for the warranty.”
A junction box is where multiple wires meet. In the context of a solar panel, a junction box joins the busbars and conducts the electricity towards the inverter.
You may have seen these in your roof cavity. In simple terms, it’s a distribution point. Think of it like an intersection on a road.
“For my girlfriend and I, TV soaps act a little like an electrical junction box. We are both heading in the same direction until the TV is turned on, then we head in different directions.”
A kilowatt is a measure of 1000 watts of electrical power. See ‘Watt’ for further explanation. It’s the amount of power that it takes to run your house at any given moment.
This number will vary because you run different appliances at different times, be it hot or cold, day or night, or if grandma is visiting with the aircon set to 37 degrees and she is using every kitchen appliance simultaneously.
“When I first enquired about domestic solar, a thousand questions were always answered with thousand watts.”
A kilowatt-hour is a unit of energy that describes electrical power over time. If the rate of energy transfer is constant, a Kilowatt-Hour is derived by multiplying electrical power in kilowatts by the total time in hours the energy transfer occurs over.
For example, if a 1kW lamp was left on for 5 hours, it is said that the lamp used 5 kWhs. Residential electricity bills are often measured in kilowatt hours. For those of us who wish to reduce our electricity bills, this is the measurement to look out for.
This number appears on your bill, often in a cute little chart comparing usage last month and the same time last year. Reduce this number and you reduce the bill. So, turn off your lights and use the clothesline instead of the clothes dryer.
Being able to measure the amount of electricity you use allows you to better monitor and control your electricity usage. Simple.
It’s a little like using the bathroom scales for weight control. When you know the critical numbers, you can instigate changes in habits to control the numbers.
“My girlfriend is so electric, I measure our time together in kilowatt hours.”
Lead-Acid batteries are the oldest rechargeable battery technology, most commonly found in cars. Their use as residential batteries is slowly dying out as they are being replaced by newer technologies.
This heavy old beast still has a place in the modern world. It’s robust, reliable and can take a fair beating.
“Lead and Acid. Toxic, yes! But if you use for its most common purpose, to power your car instead of ingesting it, you won't have a worry.”
LG Chem is a subsidiary of the Korean electronics company, LG. The company is best known for producing raw materials and chemicals. However, in recent years, LG has become a leading residential energy storage manufacturer with the release of the LG Chem RESU.
LG Chem? Never heard of them? Stay tuned.
“Our LG Chem is so efficient I’m thinking of plugging the kids in.”
LG Chem RESU
The RESU (Residential Energy Storage Unit) is a second-generation lithium-ion residential battery unit designed and manufactured by LG Chem, a subsidiary of the Korean electronics company LG.
‘By golly, that LG Chem RESU is tiny. There is no way it could store 9.8kWh.’ Look, we know you don’t care now, but you will. Your house can be battery operated with power taken from the sun, and stored in this nifty little gadget. How cool is that!
Read our review of LG Chem RESU.
“With our LG Chem RESU, we’ve added another 46 km of flashing lights to our Christmas display.”
LGCs, or Large Scale Certificates, are similar to STCs, but they are used for large-scale solar projects.
Yes. Just imagine STCs but bigger! They’re usually involved in a commercial venture, generally unrelated to yours and my domestic solar interests.
“We’re building a commercial solar power plant just so we can add LGC to our growing list of fabulous solar acronyms.”
In the context of battery systems, a lithium-ion battery is a type of rechargeable battery that relies on lithium ions moving from a negative electrode to a positive electrode to generate a current.
This is serious science. Get your lab coat on again. Even if you do get your head around this you won't be able to impress your friends with this knowledge. They’ll switch off after 30 seconds.
These batteries are awesome, however. They’re the batteries that are in your phone and your cordless drill. They have changed the way we live in so many ways.
“Lithium-Ion: once science fiction, now it’s all over the house—in fact, it powers the house!”
A meter measures the amount of power a residence draws from and contributes to the grid. Energy retailers use the meter or meter box to determine your bill size.
Your ‘meter box’ (where the meter lives) contains the meter and your circuit breakers and other electrical stuff. It’s where the power comes into your house from the grid and is distributed throughout the house.
“My daughter spends so much time under the hairdryer our electricity meter calculates more like a taxi meter.”
Microinverters are solar components which convert DC to AC at the panel level as opposed to a string inverter, which converts power at the string level.
“I’ve bought a micro-inverter for my mini-me. She's now powered at the panel.”
A monocrystalline solar cell uses crystalline structures that were uniformly grown. This results in a more uniform cell colour. Monocrystalline panels have lower defects and higher efficiency.
Ask your solar installer if your panels are built using a monocrystalline or polycrystalline structure.
“Our monocrystalline panel cells are like an army of uniformed soldiers working efficiently in perfect synchronicity.”
Solar mounting sometimes referred to as racking, refers to the equipment used to mount the solar panels onto a rooftop. The mounting system used can vary depending on the nature of the installation.
You must get this right. Using quality (we suggest Australian made) components provide safety and peace of mind. As prone to weather extremes as Australia increasingly is, ensuring your panels are firmly secured to your roof is crucial.
Be sure to confirm the brand and quality of mounting systems with your installer. Research brands and get reviews. There are cheap mounting systems on the market and they must be avoided.
“Here’s a tip, buy a good mounting system, or else your solar panels become sails or a very expensive, very shiny kite.”
A solar panel sometimes referred to as a PV panel or PV module, is a collection of laminated solar cells. A standard residential solar panel usually contains 60 individual cells.
This is the unit that collects the sun's rays, stage one of turning the sun's rays into your electricity. You have no doubt seen many of these panels adorning the roofs on many a suburban home. Expect to see more of them.
“We solar panelled the dog house, now we a have panel powered poodle with an electric woof!”
PERC (Passivated Emitter Rear Cell Technology) refers to a method of increasing panel efficiency by placing a reflective mirror-like surface behind the solar cell, allowing photons which may have escaped absorption to be reflected back into the cell.
It’s the photon police. With this outstanding device on patrol, photons have nowhere to go but to work, generating your electricity. It’s a fancy name, but its role is quite simple; it’s a device that increases the efficiency of your solar panel.
“I think our teenage kids will respond well to PERC technology. There are always more efficient when looking in a mirror.”
Panel manufacturers often provide a linear performance guarantee. This warranty guarantees a certain level of performance relative to the age of the panel, up to 25 years.
“My husband is now 53, and I’m curious as to what parts of him are still covered under the performance warranty… Thankfully, my solar panels are still covered for performance, so I know that at least I can keep him warm regardless of panel failure.”
A photon is an elementary particle that represents the smallest quantum for carrying electromagnetic radiation.
OK, we’ve defined it. Taking this definition further will require thick glasses and a lab coat. Knowing the science of photons is not going to make your electricity bill cheaper.
For us mere mortals, lets just call it sunlight.
“Our family is adding photon torpedos to the station wagon. A little blast of concentrated sunlight gets the traffic moving.”
The term photovoltaic (‘photo’ meaning light and ‘volt’ implying electricity) pertains to any technology that turns light energy directly into electrical energy, such as photovoltaic panels.
Your solar panels, the shiny things now dominating your roof, are indeed PVs or photovoltaics.
“Our neighbours say solar panels. So low class. We always refer to our array as the photovoltaics.”
A polycrystalline cell uses a crystalline structure that was not uniformly grown and therefore does not have a uniform appearance.
Ask your solar installer if your panels are built using a monocrystalline (see ‘Monocrystalline’) or a polycrystalline structure. Monocrystalline provides more efficiency and fewer defects.
“Even though I tried to explain it to him, my husband still thinks ‘Poly Crystalline’ is a school friend of our daughter.”
A product warranty guarantees that a panel will function at a satisfactory level under normal use conditions. Most product warranties range between 5 and 10 years.
“We love our kids dearly, but sometimes we wish the warranty had not expired.”
The word rebate refers to any financial incentive provided by the government to reduce the upfront cost of solar.
Yay! From now until 2032 the government will provide financial assistance to purchase solar. You don’t have to do anything to get it. The rebate will usually be factored into the purchase price of your new solar electrical system. Here is our guide to solar rebates in Australia in 2018!
“Because of the government rebate, we now have solar. Just waiting now for the government rebate on Ferraris...woohoo!”
Single Phase Power
The majority of residential homes are connected to the grid via a single phase connection. A single phase connection simply means the home is connected via a single active wire and a neutral (grounding) wire.
We guess you can sleep better knowing this. What do you care how many wires it takes to turn your lights on, just so long as they turn on, right?
“Single or three, we’re never phased by the lingo.”
A solar cell refers to the individual energy-producing units within a panel. It’s the little shiny disc-shaped circle thing that collects the sun rays. The average solar panel has 60 silicon solar cells.
“In marketing terms, we all know that sex will sell. Does solar cell just as efficiently?”
Stack and Fold
LG has developed a proprietary cell technology which they refer to as Stack and Fold. It differs from the more popular method of wrapping battery cells into a cylinder. LG claims that this method leads to higher reliability and better energy density.
For most of us, stack and fold relate to laundry or garden furniture. But in this case, it relates to a new battery technology from which we may benefit. Let’s see if the technology stacks up...or folds. Anyway, stack and fold. You heard it first here!
“No, you don’t get a stack and fold from IKEA, it’s a type of battery technology.”
STCs, or Small Scale Certificates, are a part of the Australian Renewable Energy Target scheme. Homeowners are awarded a certain number of certificates upon the installation of a solar system. They act as a kind of currency and can be traded on a market.
STCs are traded a little like shares and they have a price or value that ranges from a fixed point of $0 and $40. Currently, the price is $37 dollars, indeed a high price.
This value will fluctuate with market demands, and potentially, government intervention. This price also determines the value of the rebate you receive when purchasing a new solar system.'
As it is currently high, the rebate you receive is also high. A good time to invest in solar.
Power retailers use STCs to improve their (and Australia's) green credentials. It can be a little complicated to understand so here is a fairly user-friendly explanation of an STC:
“We have a house and business with solar. Now, because of our PVs, we have STCs and LGCs, with our LG turning DC to AC assisted by PERCs. Life doesn’t get any better!”
A solar string refers to a group of solar panels which are connected by a single wire which feeds into a string inverter. The number of panels that can exist on a single string is limited by the size of the system.
In other words, it’s when solar panels are connected together by a cable making them work in concert, or together. The inverter capacity (see ‘Inverter’ for definition) determines how many solar panels you can join or ‘string’ together by the single cable.
“Well, just how long is a piece of string? On our house, it’s 10 panels.”
String inverters are the most common form of an inverter in Australia. The current from multiple panels is conducted down a wire, called a string, towards a single inverter.
“String inverters. Turning panel after panel into perfect power.”
A supply charge, or demand charge, is a fee that homeowners are asked to pay energy retailers for access to the electricity network. This fee is dependent on the retailer.
It’s a fee for being in the club. Each retailer will have a different price. Shop around for competitive rates.
“I feel our ‘supply charge’ is a little like the old $200 for passing go. We explained it to our teenage daughter as being a little like a nightclub entry fee.”
An electricity tariff refers to the price paid for a kWh of energy. Depending on when and how energy is used, the tariff may change. There are also different tariffs for residential and commercial premises.
So, how does it relate to you?
In theory, the tariff system can be used to earn money from the electricity you generate with your solar array, but that you don’t use. That is, returning your spare electricity to the grid, but for a price. You are like a mini power station.
The government (state) or the electricity retailer will pay you a certain price per kWh that you inject into the grid. This tariff used to be very high in some states. It has reduced significantly now, however. Nonetheless, it can help you toward a zero electricity bill.
“Once upon a time, your house was your castle. Now your home is a cutting-edge power station.”
Tesla is an American automotive manufacturer specialising in electric vehicles, and they’re awesome. It is owned and run by the celebrity billionaire, Elon Musk.
In recent years, Tesla has produced a line of home battery units for both commercial and residential use including the Powerwall and Powerpack.
You can’t buy these batteries from the servo or 7/11, but you won't have to. They’re rechargeable via sunrays. They’re now getting good enough to manage all your home power needs during the evening when the sun knocks off work.
“We’ve heard that if you deck your house out with Tesla power, Elon will come over for dinner. Imagine the wine he’d bring.”
The Tesla Powerwall is a residential energy storage unit designed and built by the American automotive company, Tesla. The first generation of the Powerwall, known as the Powerwall 1.0, was released in 2015. The second-generation unit, known as the Powerwall 2.0, was released in October 2016.
Wow, what’s next? 3 and 4... obviously. Expect plenty of electricity storage! Makes the Duracell Bunny look prehistoric.
“My Tesla Powerwall is so powerful, I’m now using it to recharge my husband.”
Three Phase Power
Many rural homes and the vast majority of businesses are connected to the grid via a three-phase connection. This allows the premises to receive a higher kW input. A three-phase home is connected to the grid via three active wires and one neutral (grounding) wire.
Yep, as with single phase, it’s nice to know the term, but you’re unlikely to ever use it in a sentence.
“OK, so there’s single phase and three phase. Whatever happened to phase two?”
A warranty is a guarantee by the product manufacturer or installer to the customer that the product will continue to function at a satisfactory level. A breach of a warranty will usually result in a full or partial refund equal to the price of the original product.
Always get very familiar with your warranties. You are spending plenty of money on your new solar electrical system. You need to know how you are covered.
If you don’t understand the fine print, get advice.
“The end of a warranty period was often thought of as the expiry date of your appliance.”
A workmanship warranty is provided by the installer, guaranteeing the customer that the service has been delivered to all legal standards and at a satisfactory level. Most workmanship warranties range between 5 and 10 years, depending on the installer.
“As the saying goes, they don’t make things like they used to. Well of course not, they never used to make solar panels.”
If you want to see how much solar or battery storage could save you over the next 5 years, then take our solar saving calculator quiz below!
Or talk to an Instyle Solar expert about the best solutions for home energy storage or PV-panels.
Otherwise, head back to the solar blog to find even more great educational content.