Solar quotes are full of acronyms designed to make you nod along and sign on the dotted line. This page is your translator. We've stripped every common solar term you'll meet in a New Zealand quote, contract, or installer pitch back to plain Kiwi English, with the local context that matters: NZ retailers, NZ lines companies, and the way our grid actually works. Bookmark it, share it, and refer back to it the next time someone tries to dazzle you with "DoD", "hybrid topology", or "3-phase export limiting". By the end, you'll read a solar quote the way an installer does, which is exactly the position you want to be in before you spend $15,000 to $40,000 on a system.

How to Use This Glossary

The terms are listed A to Z. Each entry has a short plain-English definition, then a quick "Why it matters in NZ" note where the local context changes things. If you're reading a quote right now, use Ctrl+F (or Cmd+F on a Mac) to jump straight to the term that's tripping you up.

If a term you've heard isn't here, flick us a note and we'll add it. This glossary is a living document, and we want it to be the most useful one in the country.

A to E

AC (Alternating Current)

The type of electricity your house and appliances run on. Your panels produce DC, your inverter converts it to AC, and that's what powers your jug.

Amp / Ampere (A)

A measure of electrical current (flow). Most NZ homes have a 60A or 80A main switch. Why it matters: if you want a big solar or EV setup, your switchboard's amp rating can become the limiting factor before the panels do.

Array

The full set of solar panels on your roof, wired together. A "6 kW array" means the panels collectively can produce up to 6 kW under ideal sun.

Battery (Home Battery / ESS)

Stores excess solar so you can use it at night or during outages. In NZ, almost all new home batteries use LiFePO4 chemistry (see below).

Buy-Back Rate

The cents per kWh your electricity retailer pays you for solar you export to the grid. Rates vary widely; see our Dynamic Tariff & Buy-Back Engine for current NZ retailer comparisons.

Certificate of Compliance (CoC)

The signed document from your licensed electrician confirming the install meets the wiring regulations. Never accept a system without one. It's your proof for insurance, resale, and your lines company.

Clipping

When your panels produce more DC than the inverter can handle, the inverter "clips" the excess. A small amount is normal and even intentional with oversized arrays.

DC (Direct Current)

The type of electricity solar panels produce. Has to be converted to AC by the inverter before your home can use it.

Degradation

The slow drop in panel output over time. Quality panels degrade roughly 0.4 to 0.55% per year, so after 25 years you're still getting around 85 to 90% of day-one output.

DoD (Depth of Discharge)

The percentage of a battery's capacity you can safely use. A 10 kWh battery with 90% DoD gives you 9 kWh of usable energy. Why it matters: compare batteries on usable kWh, not nameplate kWh.

EECA

The Energy Efficiency and Conservation Authority. The NZ government body promoting energy efficiency and renewables. A reputable source for solar guidance.

Export / Import

Export is solar going from your home out to the grid. Import is power coming from the grid into your home. Your smart meter measures both separately.

Export Limit

A cap your lines company puts on how much solar you can send back to the grid. Common in some regions (Vector, Orion, etc.) for larger systems. Always check the export limit before sizing.

F to L

Grid-Tied

A solar system connected to the national electricity grid. The standard setup for nearly every NZ home. The opposite is off-grid, which is rare and expensive for most homeowners.

Hybrid Inverter

An inverter that can handle solar panels and a battery on the same unit. "Battery-ready" usually means you've installed a hybrid inverter but haven't added the battery yet.

Inverter

The brain of your solar system. Converts DC from the panels into AC for your home, and manages export to the grid. Typically warrantied 10 to 12 years.

Islanding (Anti-Islanding)

A safety feature. If the grid goes down, your inverter automatically shuts off solar export so it can't electrocute the linesman fixing the fault. Why it matters: a standard grid-tied system will not power your home during a blackout unless you have a battery with backup capability.

kW (Kilowatt)

A measure of power: how much electricity is flowing right now. A 6 kW solar array can produce up to 6 kW at peak sun. Think of it like the speed your car is travelling.

kWh (Kilowatt-hour)

A measure of energy: how much electricity has been produced or used over time. A 6 kW array might generate 25 kWh on a sunny Auckland day. Think of it like the distance your car has driven. Your power bill is measured in kWh.

Lines Company

The company that owns the poles and wires in your area (Vector in Auckland, Orion in Christchurch, Wellington Electricity in Wellington, Powerco in the Bay of Plenty, Aurora in Otago, etc.). Different from your retailer. They charge you a daily fixed line charge.

LiFePO4 (Lithium Iron Phosphate)

The current standard battery chemistry for residential solar in NZ. Safer than older lithium-ion (much lower fire risk), longer cycle life (6,000+ cycles), and the chemistry behind brands like BYD, Sungrow, and most Tesla Powerwall 3 alternatives.

M to R

Micro-inverter

A small inverter attached to each individual panel, rather than one big string inverter for the whole array. More expensive, but better when you have shading issues. Enphase is the dominant brand in NZ.

Monocrystalline (Mono PERC, TOPCon, HJT)

The panel type used in nearly every modern NZ residential install. PERC is the older mono standard; TOPCon and HJT are newer, slightly more efficient generations now becoming the norm.

MPPT (Maximum Power Point Tracker)

The bit of the inverter that squeezes the maximum power out of your panels under changing conditions (sun angle, partial shade, temperature). More MPPTs on an inverter generally means better performance on complex roofs.

Net Metering

A billing arrangement where you're charged or credited based on the net difference between import and export. NZ doesn't do classic net metering; we have separate import and export rates instead, which is why the buy-back rate matters so much.

Off-Grid

A solar system not connected to the national grid. Requires significant battery storage and usually a backup generator. Rare and expensive for most NZ homes; almost never the right answer unless you genuinely have no grid connection available.

Peak / Off-Peak / Shoulder

Time-of-use periods set by your retailer. Power costs more at peak (typically 7-9am and 5-9pm) and less off-peak (overnight). Why it matters: a battery lets you avoid peak rates by discharging stored solar during expensive windows.

Photovoltaic (PV)

The proper name for solar panels: cells that convert photons (light) into voltage (electricity). When you see "PV system", it just means "solar system".

ROI (Return on Investment)

How quickly your system pays itself off in power-bill savings. Most NZ residential systems land between 7 and 12 years, depending on size, location, retailer, and household usage. Run the numbers on our Solar System Cost & ROI Calculator.

S to Z

Single-Phase vs Three-Phase

Refers to how electricity is delivered to your house. Single-phase is standard for most NZ homes. Three-phase is more common in larger or rural homes, lifestyle blocks, and any property with heavy load (heat pumps, EV chargers, pottery kilns). Three-phase often allows larger solar systems with higher export limits.

Smart Meter

The digital meter installed by your retailer that measures import and export separately, every half hour. Required for solar. If you don't have one, your retailer will replace yours for free when you connect solar.

String Inverter

The standard, cost-effective inverter type. Panels are wired together in a "string" and run through a single inverter (Fronius, Sungrow, GoodWe, SolarEdge are common in NZ).

STC (Standard Test Conditions)

The lab conditions panels are rated under. Real-world output in NZ will be lower because actual conditions are never lab-perfect. Don't expect nameplate kW on a hot Hawke's Bay afternoon.

Tilt and Azimuth

Tilt is the angle of your panels from horizontal (roof pitch). Azimuth is the direction they face. North-facing at around 25 to 35 degrees is the NZ sweet spot, but east-west splits can work brilliantly for households with morning and evening usage.

VPP (Virtual Power Plant)

A scheme where your battery is networked with others and a retailer can draw on it during grid peaks, paying you for the privilege. Emerging in NZ but not yet mainstream.

Warranty (Product vs Performance)

Panels typically have two warranties: a product warranty (defects, usually 12 to 25 years) and a performance warranty (guaranteed output retention, usually 25 to 30 years). Read both. They are not the same document.

Yield (Specific Yield)

The kWh produced per kW of installed solar per year. In NZ, expect roughly 1,250 to 1,450 kWh per kW per year depending on region (Northland highest, Southland lowest), per EECA and NIWA solar irradiance data.

What to Do With This Glossary

Reading a quote with this page open is the single fastest way to level the playing field with an installer. Look out for:

  • kW vs kWh confusion, especially in battery quotes. Make sure you're comparing usable kWh, not nameplate.
  • DoD figures buried in spec sheets. A 13.5 kWh battery at 80% DoD gives you less than an 11 kWh battery at 100% DoD.
  • Export limits that quietly cap your system's return. Ask your installer to confirm your lines company's limit in writing.
  • Single-phase vs three-phase implications, especially if you plan to add an EV charger later.
  • Performance warranty vs product warranty. Marketing material loves to quote the longer of the two.

If you want to check whether a green loan applies to your situation while you're at it, head to our Green Finance Qualifier Tool. And if you'd rather skip the homework and get three vetted installers to quote you directly, that's what we built the main hub for.

Frequently Asked Questions

What's the difference between kW and kWh, in one sentence?

kW is power (the rate); kWh is energy (the total over time). A 6 kW system running at full output for one hour produces 6 kWh.

Why does my installer keep saying "battery-ready"?

It means they've installed a hybrid inverter that can accept a battery later, but haven't added the battery yet. Useful for spreading the cost; just confirm the inverter is genuinely compatible with the battery brand you'd want.

If my power goes out, will my solar keep working?

No, not on a standard grid-tied system. Anti-islanding protection shuts solar off during a blackout for safety. You need a battery with explicit backup capability (and the right inverter setup) to keep the lights on.

Is "off-grid" the goal?

For 99% of NZ homes, no. Grid-tied with a battery gives you most of the independence at a fraction of the cost and complexity. Off-grid only makes sense when you have no economical grid connection.

What's a realistic NZ buy-back rate?

It varies by retailer and can change. Rather than memorising numbers that go stale, check the live comparison on our Dynamic Tariff & Buy-Back Engine.

What does "LiFePO4" actually mean for me as a homeowner?

It means a safer chemistry (very low fire risk), a longer lifespan (often 6,000+ cycles), and the assurance that you're buying current-generation tech rather than older lithium-ion.

How do I know if I have single-phase or three-phase power?

Check your main switchboard or ask your electrician. Three-phase will typically have three thicker live conductors entering the board. Most urban NZ homes are single-phase.

Are these terms used differently in NZ than overseas?

Yes, in important ways. We don't have classic net metering, our buy-back rates are retailer-set rather than government-mandated, overseas rebate and certificate schemes don't apply here, and our lines companies are regional. Be cautious of international advice; the maths is different in Aotearoa.

Bottom Line

You don't need to memorise every term on this page. You just need to know where to look when an installer drops one on you. Once you can translate the jargon, the rest of the buying process gets dramatically easier: you ask sharper questions, compare quotes properly, and spot when a number has been quietly stretched.

That's the whole reason this page exists. Solar should be a clear, confident purchase, not a guessing game.