Plug-in solar glossary

Most of these definitions are drawn from the draft Technical Bridging Standard (clause 3) and the consultation paper, put into everyday words. Where a term has a wider meaning outside plug-in solar, I have kept to the meaning that matters here.

A

AC (alternating current)

The kind of electricity in your power points. In WA homes it is nominally 230/240 V at 50 Hz, the range the draft standard covers. A plug-in kit’s inverter turns the panels’ DC into AC.

Anti-islanding

A safety function that makes an inverter stop supplying power when the grid goes down, so it cannot keep a cut-off section of the network live (draft clause 3.1). Plug-in inverters must pass the AS/NZS IEC 62116 anti-islanding test.

Apparent power

Voltage multiplied by current, measured in volt-amperes (VA). See VA.

AS/NZS 3112

The Australian and New Zealand standard for the Type I plug, the normal three-pin plug used here. The draft requires plug-in kits to use a Type I plug to AS/NZS 3112:2025 with half-insulated pins.

AS/NZS 4777.2

The standard for how inverters connected to the low-voltage grid must behave, including the tests makers run to prove it. The draft requires plug-in inverters to use its region B settings in Western Power’s area and region C in Horizon Power’s, with the reactive power, volt-var and demand response clauses left out.

B

Balcony solar

The everyday name for plug-in solar, from Germany, where many kits hang on apartment balconies. It means the same thing as a plug-in generator on this site.

BMS (battery management system)

The electronics that monitor a battery’s charge, temperature and safety, and disconnect it from the inverter if anything goes outside its limits. The draft requires the BMS to act on its own and fail safe.

Building and Energy

The WA Government’s building and electrical safety regulator, part of the Department of Local Government, Industry Regulation and Safety (LGIRS). LGIRS is consulting on the plug-in solar rules with DEED.

D

DC (direct current)

Electricity that flows one way, as produced by solar panels and stored in batteries. The draft limits a kit’s panels and battery to 2,000 W DC combined.

DEED and Energy Policy WA

The Department of Energy and Economic Diversification. Its Energy Policy WA team prepared the draft standard and runs the consultation.

DIN VDE V 0126-95

Germany’s technical specification for plug-in solar devices, “Part 95: Safety requirements and tests”. The WA draft is based on it, with changes for Australian plugs, wind loads, grid codes and batteries. Where the two differ, the WA standard takes priority.

E

EESS (Electrical Equipment Safety System)

The national scheme for household electrical equipment safety, which WA takes part in. Under it, a registered Australian or New Zealand “responsible supplier” declares equipment safe and applies the RCM. The plan is for plug-in kits to be certified through EESS like any other appliance.

Embedded network

A private electricity network inside a site, behind one connection to the grid. The FAQ gives “apartments, strata and caravan parks” as examples, and says metering in embedded networks is one reason there are no export payments for now.

F

Feed-in tariff

A payment for electricity you send to the grid. In WA, rooftop solar owners may get a buyback payment under the Distributed Energy Buyback Scheme (DEBS) from Synergy or Horizon Power. The FAQ says plug-in systems would get no export payments for now.

H

Horizon Power

The utility responsible for generation, distribution and sale of electricity outside the SWIS, in regional and remote WA. It runs the North West Interconnected System in the Pilbara, the Esperance network and over 30 smaller networks. Plug-in owners in its area would notify Horizon Power.

Household

In the draft, “a single dwelling unit with its own electricity supply and switchboard”. Each apartment with its own switchboard counts as a separate household. Only one plug-in generator is allowed per household.

I

Inverter

The box that turns DC from solar panels or a battery into AC for your home. A plug-in kit’s inverter is a “supplementary supply inverter”: it matches the grid and cannot create a supply of its own. The draft caps it at 800 VA and 3.5 A.

K

kW (kilowatt)

1,000 watts. A measure of power at a moment in time. The draft allows up to 2 kW of panels and battery on the DC side.

kWh (kilowatt-hour)

A measure of energy: 1 kW running for one hour. It is the “unit” on your power bill and how battery size is measured. The government expects most plug-in batteries to be 5 kWh or less.

L

LFP (lithium iron phosphate)

A lithium battery chemistry the draft allows for plug-in batteries. The draft bans NMC (nickel manganese cobalt) chemistry.

M

MCB (miniature circuit breaker)

A switch in your switchboard that cuts a circuit off if too much current flows. The draft describes a modern board as having an MCB per circuit with a shared RCD upstream, or an RCBO per circuit.

Microinverter

The everyday name for the small inverter used with one or a few panels. The draft simply calls it the inverter.

N

NATA

The National Association of Testing Authorities, which describes itself as “Australia’s leading national accreditation body, recognised by government”. Under the proposal, plug-in kits would be type-tested by NATA-accredited labs.

P

Plug-in generator

The draft standard’s term for a plug-in solar and battery system: panels, inverter, mounting and a cable with a Type I plug, with an optional battery on the DC side. Formally, “a device that conforms to this TBS”.

R

RCBO

A residual current breaker with overcurrent protection: a safety switch and circuit breaker in one, for a single circuit.

RCD (residual current device)

A safety switch. It cuts power when it detects current leaking out of a circuit, such as through a person. Type AC RCDs are an older kind that the consultation paper says DC leakage could “blind”. Western Power says type AC must not be installed in Australia from 30 April 2023, with type A required instead.

RCM (Regulatory Compliance Mark)

The tick inside a triangle on electrical products. In-scope electrical equipment must not be sold in Australia without it. Under the proposal, certified plug-in kits would carry it.

S

Sodium-ion (Na-ion)

A battery chemistry that uses sodium in place of lithium. The draft allows it for plug-in batteries, alongside LFP.

Switchboard

The box with your home’s circuit breakers and safety switches. The draft defines it as the assembly containing the protective devices for the final circuits. Plug-in kits come with a green label to stick on it.

SWIS (South West Interconnected System)

WA’s main grid, running from Kalbarri in the north to Albany in the south and Kalgoorlie in the east, including Perth. Western Power runs its network. More than 40% of homes on it already have rooftop solar, according to the ABC.

Synergy

The retailer that sells electricity and generates power in the SWIS. It sends the bill. It is not the network operator you would notify about a plug-in kit.

T

Technical Bridging Standard (TBS)

The draft WA standard for plug-in solar and battery systems, DR EPWA-TBS-75-001, Version 1, October 2026. It “bridges the gap” until national standards are updated. Version 2 is expected by February 2027.

Type test

A test on a sample of a product design to show the design meets the standard. Plug-in kits must be type-tested before they can be registered.

V

VA (volt-ampere)

The unit of apparent power, used for the 800 VA inverter limit. For small solar inverters, which make little reactive power, my reading is that VA and watts come out close. That is why the government FAQ says 800 W while the draft says 800 VA.

W

W (watt)

The unit of power that does useful work. 1,000 W is 1 kW.

Western Power

The government-owned corporation that builds, maintains and operates the electricity network in the SWIS, covering Perth and the South West. Plug-in owners in its area would notify Western Power.

Wind region

An area in the wind loading standard AS/NZS 1170.2, used to set how strong structures must be. The draft requires mounts to be checked up to region B. Cyclone regions C and D, in parts of the Kimberley, Gascoyne and Pilbara, are proposed to be left out of mandatory testing.